Dissertation Branch Iv Conservative Dentistry And

A COMPARATIVE EVALUATION OF MICROLEAKAGE

AROUND CLASS V CAVITIES RESTORED WITH FIVE

DIFFERENT TOOTH COLOURED RESTORATIVE

MATERIALS – AN IN VITRO STUDY

DISSERTATION

submitted to

THE TAMILNADU Dr.M.G.R.MEDICAL UNIVERSITY

In partial fulfilment of the degree of

MASTER OF DENTAL SURGERY

BRANCH IV

CONSERVATIVE DENTISTRY AND ENDODONTICS

2017 – 2020

CERTIFICATE

This is to certify that this dissertation titled “A Comparative Evaluation of

Microleakage Around Class V Cavities Restored With Five Different Tooth

Coloured Restorative Materials – An In Vitro Study” is a bonafide record of the work done by Dr. L.ASHOK under our guidance during his post graduate study during the period of 2017-2020 under The Tamil Nadu Dr. M.G.R Medical

University, Chennai, in partial fulfilment for the degree of Master Of Dental

Surgery in Conservative Dentistry and Endodontics, Branch IV. It has not been submitted (partial or full) for the award of any other degree or diploma.

Dr RAJESH S, MDS Dr. J. MANO CHRISTAINE ANGELO, MDS

Professor,HOD &Guide Professor &Co-Guide Department of Conservative Department of Conservative Dentistry &Endodontics, Dentistry & Endodontics, Sree Mookambika Institute of Dental Sree Mookambika Institute of Dental Sciences, Sciences, Kulasekharam. Kulasekharam.

CERTIFICATE II

This is to certify that this dissertation work titled “A Comparative

Evaluation of Microleakage Around Class V Cavities Restored With Five

Different Tooth Coloured Restorative Materials – An In Vitro Study” of the candidate Dr. L.ASHOK, with registration number 241717251 for the award of

Master of Dental Surgery in the branch of Conservative Dentistry and Endodontics,

[Branch- IV]. I personally verified the urkund.com website for the purpose of plagiarism Check. I found that the uploaded thesis file contains from introduction to conclusion pages and result shows 7 percentage of plagiarism in the dissertation.

Guide & Supervisor sign with Seal.

Date:

Place:

SREE MOOKAMBIKA INSTITUTE OF DENTAL

SCIENCES, KULASEKHARAM

ENDORSEMENT BY THE PRINCIPAL / HEAD OF THE

INSTITUTION

This is to certify that the dissertation entitled “A Comparative Evaluation of

Microleakage Around Class V Cavities Restored With Five Different Tooth

Coloured Restorative Materials – An In Vitro Study” is a bonafide research work done by Dr. L.ASHOK the guidance of Dr. Rajesh S., M.D.S, Professor and Head of the Department, Department of Conservative Dentistry and Endodontics, Sree

Mookambika Institute of Dental Sciences, Kulasekharam.

Dr.Elizabeth Koshi, MDS, PRINCIPAL Sree Mookambika Instituteof Dental Sciences, V.P.M Hospital Complex, Padanilam, Kulasekharam, Kanyakumari District, Tamil Nadu - 629161

Date:

Place:

DECLARATION

I hereby declare that this dissertation “A Comparative Evaluation of

Microleakage Around Class V Cavities Restored With Five Different Tooth

Coloured Restorative Materials – An In Vitro Study” is a bonafide record of work undertaken by me and that this thesis or a part of it has not been presented earlier for the award of degree, diploma, fellowship or similar title of recognition.

Dr. L.ASHOK PG Student Department of Conservative Dentistry & Endodontics Sree Mookambika Institute of Dental Sciences Kulasekharam.

ACKNOWLEDGEMENT

I would like to Thank Lord Almighty for his guidance and blessings given to complete this research study successfully.

I would like to express my deep gratitude and sincere thanks to our

Chairman Dr. C.K Velayuthan Nair , M.B.B.S., M.S and Director Dr. Rema V.Nair

M.B.B.S., M.D, D.G.O for their academic support and facilities provided for me to complete my study .

I would like to thank our Trustees Dr.Vinu Gopinath .M.B.B.S., M.S.,M.Ch and Dr. R.V Mookambika M.B.B.S.,M.D.,D.M., for their help and support to complete my study.

I would like to extend my profound gratitude and sincere thanks to my guide

Dr.Rajesh.S MDS, Professor & Head Of The Department ,Department Of

Conservative Dentistry And Endodontics , for his skillful suggestions ,boundless patience ,timely help, constant advice, and emotional support all through my study as well as during my post-graduation period.

I express my sense of gratitude and heartfelt thanks to my co-guide Dr. Mano

Christaine Angelo Professor, Department Of Conservative Dentistry And

Endodontics, for his brilliant advices, and constant support throughout my postgraduation period and throughout this study.

I would like to acknowledge my heartfelt gratitude and respect to Dr. Vijay

Mathai, M.D.S, professor, Department Of Conservative Dentistry And Endodontics for his help and support to complete my study.

I would like to express my gratitude to Dr.Vineet.R.V M.D.S., Dr.Sarah

Christopher M.D.S., Reader, Dr.Vineesh K M.D.S., Dr.Mohammed Riyaz., M.D.S.,

Dr.Elizabeth Issac M.D.S., Senior lecturers and Dr.Manoj Kumar B.D.S for their constant encouragement and inspiring guidance throughout the course of this study.

I would like to thank Dr. Rimal issac, Assistant professor, Noorul Islam

Centre For Higher Education, Kumarakovil, for his constant encouragement and guidance throughout the course of this study.

I would like to extend my sincere thanks to Dr.Radhika, Assistant Professor

Department of Pathology and Dr Vishwajyothi, Post graduate student, College of

Agriculture, Vellayani, Thiruvanathapuram for their guidance in doing stereomicroscopic analysis.

I would like to extend my thanks to Dr. Porchelvan and Dr.Sharath Babu for helping me with statistical works.

I would like to thank my seniors, Dr.Soumya .T.S, Dr.Sreelekshmi.V.J. MDS

Dr. Priya Alice Mathew and Dr. Sanjana Paul for their constant moral support and encouragement.

I would like to thank my fellow post graduates Dr.Swathi.V.S, Dr. Rajesh S,

Dr. Nandhini.G, Dr. Reshve P Verghese, Dr. R. Deepak for their whole hearted cooperation and encouragement.

I would like to thank my parents and relatives for their love, prayers and continuing support rendered throughout my post-graduation period.

CONTENTS

Sl. No TITLE PAGE NO

1 List of Tables i

2 List of Figures ii

3 Abstract iii

4 Introduction 1-5

5 Aims & Objectives 6

6 Review of Literature 7-33

7 Materials & Methods 34-38

8 Results & Observations 39-40

9 Discussion 41-48

10 Summary & Conclusion 49-50

11 Tables iv-xi

12 Figures xii-xx

13 Bibliography xxi-xxviii

LIST OF TABLES

Table-1 Mean occlusal microleakage scores

Table-2 Mean gingival microleakage scores

Occlusal and gingival Microleakage scores of all the tested Table-3 specimens

Table-4 (a) Oneway statistical analysis of gingival microleakage

Table-4(b) Post Hoc analysis of gingival microleakage scores

Table-4(c) Non parametric statistical test of gingival microleakage scores

Table-5(a) Oneway statistical analysis of occlusal microleakage

Table-5(b) Post Hoc analysis of occlusal microleakage scores

Table-5(c) Non parametric statistical test of occlusal microleakage scores

LIST OF FIGURES

Fig. 1 Selected specimens

Fig 2 Conventional galss ionomer

Fig 3 Zirconomer

Fig 4 Giomer

Fig 5 Cention N

Fig 6 Ionoseal

Fig 7 Silver nitrate dye

Fig 8 Specimen immersed in a dye for dye penetration

Fig 9 Cross section of specimen for microleakage evaluation

Fig 10 Stereomicroscope examination of specimens

Fig 11 Stereomicroscopic picture of Conventional GIC restoration

Fig 12 Stereomicroscopic picture of Zirconomer restoration

Fig 13 Stereomicroscopic picture of Giomer restoration

Fig 14 Stereomicroscopic picture of Cention N restoration

Fig 15 Stereomicroscopic picture of Ionoseal restoration

Fig16 Mean Comparision of Occlusal Microleakage scores

Fig 17 Mean Comparision of Gingival Microleakage scores

ABSTRACT Abstract

Aim: The aim of this study is to compare and evaluate the microleakage of five different tooth coloured restorative materials.

Methodology: Forty caries free human permanent maxillary premolar of comparable dimensions extracted for orthodontic purposes were selected divided into five groups of 8 each. Class V cavities were prepared and restored using

Conventional GIC (Group I), Zirconomer (Group II) and Giomer (Group III),

Cention N (Group IV), Ionoseal (Group V) restorative materials. All samples were then submitted to thermocycling. The external surfaces of each tooth were coated with nail varnish except a 1 mm wide margin surrounding the restoration. Samples were then immersed in 50% Wt silver nitrate dye for 6 hours in a dark container at room temperature for dye penetration. Specimens were sectioned buccolingually through the restoration and evaluated under stereomicroscope 30X magnification for microleakage.

Statistical Analysis Used: One way analysis of variance (ANOVA) followed by post hoc Tukey HSD test and non-parametric Kruskal-wallis test to determine the significant difference at occlusall and gingival margin. P< 0.05 will be considered to be statistically significant.

Results: Stereomicroscopic evaluation shows maximum microleakage is seen in

Conventional GIC (Group I) and minimum microleakage seen in Ionoseal

(GroupV), a resin reinforced light cure glass ionomer composite.

Conclusion: Under the limitation of this in vitro study, among all the groups

Ionoseal, a resin reinforced light cure glass ionomer showed the least microleakage at the gingival and occlusal wall.

iii

INTRODUCTION Introduction

The fundamental goal of a restoration is to restore the proper function, tooth form and esthetics while maintaining the physiologic integrity of the teeth in harmony with the oral environment. The integrity and durability of the marginal seal is an important factor in the longevity of dental restorative materials.1 A marginal gap is left between the cavity wall and the restorative material leading to microleakage.2

Microleakage is defined as the clinically undetectable passage of bacteria, molecules or ions, fluids between the cavity wall and the restorative materials.3

Microleakage is the major clinical cause for the failure of restorations in class V cavities, as margins of such restorations are generally located in dentin/cementum. The ideal requirements for restorative material are that it should have a coefficient of thermal expansion and biocompatibility similar to that of natural tooth structure, have a good color stability, excellent marginal seal, and the ability to adhere chemically to enamel and dentin.4

According to Bergenholtz et al., Microleakage has been used to evaluate the success of any restorative material used in the oral cavity since it is a major contributing factor to secondary caries and pulpal irritation.

Microleakage induced by polymerisation shrinkage continues to be a major concern for the clinical longevity of dental restorations.5

With the constant increase in aesthetic demands, tooth coloured restorative materials are widely used in restoration of class V cavities.6

Introduction

Tooth coloured aesthetic restorative materials commonly used in practice are

Conventional Glass Ionomer cements, Zirconomer, Giomer, Ionoseal, Cention N etc.,

Glass Ionomer Cements (GICs) was invented by Wilson and kent in early

1970s. Advantages of glass ionomer cement include, ability to bond chemically to dental hard tissues and release of fluoride. Co-efficient of thermal expansion of glass ionomers are similar to tooth structure provides good marginal adaptation, good retention of restoration and less microleakage in clinical conditions.3

Giomers are hybrid between resin composites and glass ionomers. Giomers have several advantages includes increased wear resistance, increased radiopacity, improved light diffusion, shade conformity, high fluoride release and fluoride rechargability which are similar to GIC. Giomers uses pre-reacted glass filler technology where fluroaluminosilicate glass fillers are pre reacted with polyacrylic acid to form a “wet siliceous hydrogel” stable phase, which is then freeze dried, milled, silane treated and ground to form PRG fillers. Depending on the degree of reaction of the glass ionomer cement with acid PRG fillers are divided into two types, S-PRG and F-PRG. In S-PRG (surface reaction type) reaction occurs only on the surface and it has the benefits of fluoride release and recharge, reinforcement of tooth structure, remineralization of dentin acid buffering capacity and antiplaque effect. In F-PRG (full reaction type) reaction occurs throughout. F-PRG undergo degradation faster than S-PRG.3 Beautifil II uses S-PRG (surface reaction type) where only the surface of the glass filler is attacked by polyacrylic acid and a glass core remains unaltered.4

Introduction

Zirconomer defines a recently introduced class of restorative glass ionomer that promises the strength and durability of amalgam with the protective benefits of glass ionomer while completely eliminating the hazard of mercury and overcome the disadvantages of traditional glass ionomer. The incorporation of zirconia fillers in the glass component of zirconomer reinforces the structural integrity of the restoration and imparts enhanced mechanical properties for the restoration of posterior load bearing areas where the conventional restorative of choice is amalgam. Hence, it is also termed as White Amalgam.5 Combination of outstanding strength, sustained fluoride protection and durability deems it ideal for permanent posterior restoration in patients with high caries incidence as well as cases where strong structural cores and bases are required.

Cention N is a newer class of restorative material offers tooth-coloured esthetics together with high flexural strength. Cention N belongs to the materials group of Alkasites. Material is supplied as powder and liquid. The liquid composed of dimethacrylates and initiators. Powder consists of initiators, patented glass fillers and pigments. This patented alkaline filler (Isofiller) increases the release of hydroxide ions to regulate the pH value during acid attacks, thereby, preventing the demineralization. The Moreover, the release of large numbers of fluoride and calcium ions are responsible for the remineralization of dental enamel. The highly cross-linked polymer structure is responsible for the high flexural strength. The initiator system enables good chemical self-curing. It has optional additional light curing. The ratio of organic/inorganic content and monomer composition of the material is also responsible for the low volumetric shrinkage leading to decreased microleakage.6

Introduction

Ionoseal is a resin reinforced glass ionomer liner. It is a light-curing glass ionomer composite cement used for lining under restorations, extended fissure sealing and smaller lesions. Ionoseal has several advantages includes time saving, easy, quick and hygienic application, ready for use one-component material, It has high compressive strength (226 mpa), High biocompatibility, important property of fluoride release against secondary caries and Radiopaque. Ionoseal is delivered in the

NDT-syringe (Non-Dripping-Technology) which is used for fine flowing materials.

After having applied pressure to it, it pulls back, preventing any running or dripping of the syringe. The desired amount of Ionoseal can be dosed and and helps to place the material precisely. In addition, proven properties of Ionoseal, are high compressive and transverse strength, have been maintained while its viscosity was improved and least microleakage.

The relationship between marginal leakage in restorations and type of

restorative materials used has been extensively studied both in laboratorical and

clinical experiments. In the absence of definitive clinical data, laboratory

microleakage studies are a well-accepted method of screening adhesive restorative

materials for marginal seal.

Thus, the creation of a perfect seal on the restoration-tooth interface is still

one of the prime goals of restorative dentistry in order to prevent the penetration of

contaminants and attain the lost peripheral seal of dentin.2

The utmost important criteria of a restorative material is to provide a

adequate seal in tooth-restoration interface to prevent the ingress of microorganisms,

oral fluids, molecules or ions beneath the restoration thereby to improve the

longevity of restoration.

Introduction

Microleakage around dental restorative materials is a major problem in clinical dentistry.7 Microleakage can cause a variety of adverse effects, such as secondary caries, higher sensitivity of the restored tooth, and interfacial staining leading to pulp pathology.8

Tooth-colored restorative materials have gained popularity due to increasing demand of esthetics.9 It is an elemental goal to determine the microleakage of such materials to maintain the physiological integrity of the teeth. This study was done to comparatively evaluate the microleakge of five tooth coloured restorative materials, namely, Conventional Glass Ionomer cements, Zirconomer, Giomer, Ionoseal,

Cention N restored in class V cavities.

AIMS & OBJECTIVES Aims &Objectives

Aim:

To compare and evaluate the microleakage of five different tooth coloured restorative materials.

Objective:

To compare and evaluate the microleakage of five different tooth coloured restorative materials to determine the tooth coloured restorative material showing the least amount of microleakage.

REVIEW OF LITERATURE Review of literature

REVIEW OF LITERATURE

Kaplan et al.199210 compared the microleakage of GIC and a bonded composite resin restoration in retentive and nonretentive cavity preparations of cervical cavities using Ketac Fil GIC (ESPE-Premier, Norristown, Pa.) and

Scotchbond 2 dentinal bonding agent (DBA) (3M Co., St. Paul, Minn.) and Silux

Plus composite resin (3M Co.). Ketac Fil glass ionomer cement (GIG) and

Scotchbond 2 dentinal bonding agent (DBA)/Silux Plus composite resin restorations were inserted in cervical cavity preparations of extracted human teeth. After thermocycling, the specimens were invested and sectioned longitudinally and horizontally through the center of the restoration. Microleakage was evaluated as a ratio of the extent of methylene blue dye penetration at the tooth-restoration interface.and concluded that Both the GIC (Ketac Fil) and the bonded composite resin (Scotchbond 2/Silux Plus) restorations exhibited some leakage. Both types of restorations displayed considerably less overall leakage in retentive than in nonretentive cavity preparations. The most desirable results in this study were recorded with Scotchbond 2 adhesive/Silux Plus composite resin in retentive cavity preparations. Ketac Fil GIC restorations inserted without a matrix strip exhibited less leakage than those inserted with a matrix strip. More teeth with non retentive composite resin restorations showed dye penetration in the dentin toward the pulp than teeth with corresponding glass ionomer restorations.

Hallett & Garcia-Godoy et al.199311 compared the Microleakage of two resin-modified glass ionomer cement (GIC) restorative material with two conventional galss ionomer cement. Forty-five noncarious extracted human molars were prepared with standardized Class V cavity outlines on the buccal and lingual

Review of literature surfaces. The occlusal margin was in enamel and the gingival margin was in dentin/cementum. All were restored according to the manufacturers' instructions.

After thermocycling, 30 teeth were placed in 2% basic fuchsin dye for 24 h, sectioned and viewed with a stereomicroscope to assess microleakage. The other 15 teeth were sectioned, replicated and prepared for marginal gap evaluation using a

SEM and he concluded that resin-modified GIC restorative material showed significantly less microleakage against enamel and dentin/cementum compared to the conventional GIC restorative (p<0.01). Marginal gap formation for both resin modified GIC restorations was limited to the axial wall of the restorations.

Franca FMG et al. 200412 evaluated quantitatively the microleakage in class

V cavities restored with one-bottle and self-etching adhesive systems with and without previous acid etching. Single Bond and Prime & Bond one-bottle adhesive systems and Clearfil Mega Bond self-etching adhesive system were analysed. One hundred and twenty sound human premolar teeth were randomly divided into 6 groups, and 20 class V restorations were prepared in the root dentin to test each bonding system. Each bonding system was used with and without acid etching.

Specimens were prepared, dyed with 2% methylene blue, sectioned, triturated, and evaluated with an absorbance spectrophotometer test in order to quantify the infiltrated dye. Results showed that No significant differences in microleakage val- ues were found among the adhesive systems when no etching agent was used. Single

Bond showed statistically lower microleakage than Clearfil Mega Bond and Prime

& Bond 2.1 when 37% phosphoric acid was used to acid etch the dentin. Single

Bond and Clearfil Mega Bond adhesive systems presented the same behavior when

Review of literature the manufacturers instructions were followed, the first used with previous etching and the latter with no etching.

Mali P et al.20067 evaluated and compared the microleakage of glass ionomer, composite resin and compomers in class V cavities using silver nitrate dye penetration and analysed under stereomicroscope. Class V cavities were made in thirty intact caries free premolars and restored with restorative materials to be tested respectively. The teeth were thermocycled and subjected to silver nitrate dye penetration. They were subsequently sectioned buccolingually. Microleakage was evaluated under a stereomicroscope. Study concluded that microleakage was evident in all restorative materials, with glass ionomer showing maximum leakage followed by composite resin. Compomer demonstrated the best results with minimum leakage.

Awliya & El-Sahn et al.200813 investigated the leakage pathway of facial and lingual Class V cavities restored with different flowable resin composites bonded with one bonding agent by examining the resin/dentin interface in Class V cavities. Flowable composites used were Grandio Flow, Filtek Flow and Admira

Flow. Hybrid composite used is Z250. Forty Class V cavities were etched with 37% phosphoric acid gel; Single Bond dental adhesive was applied, then the cavities were randomly divided into four groups (n=10). Three groups were restored with one of three flowable resin composites (Grandio Flow, Filtek Flow and Admira Flow). The fourth group was restored with Z250 (hybrid resin composite) to serve as a control.

The specimens were then placed in 50% w/v silver nitrate solution for 24 hours and immersed in a photo developing solution for eight hours. Thereafter, the specimens were sectioned bucco-lingually, polished, mounted on stubs, gold sputter coated and

Review of literature examined by scanning electron microscope. Silver particle penetration length with and without gap formation was measured directly on the scanning electron microscope monitor and calculated as a percentage of the total length of the cut dentin surface that was penetrated by silver nitrate.And concluded that Filtek Flow and Admira Flow resin composite showed a significant microleakage pattern with gap formation at the restoration/dentin interface. Grandio Flow showed a similar leakage pattern to Z250 hybrid resin composite, where no gaps were seen at the restoration/dentin interface. Silver ions penetrated beneath the resin impregnated layer, which is consistent with nanoleakage. The bonding system used in this study did not achieve perfect sealing at the restoration/dentin interface.

Eden E et al .200914 evaluated the reliability of marginal leakage assessment

of self-etch adhesive Class II resin composite restorations in primary molars

prepared in vivo using the micro-CT. Fourteen primary molars, divided over seven

ART and seven traditional resin composite Class II restorations, were subjected to

marginal leakage test using a 50% (w/v) silver nitrate solution for 4 hours by a

micro-CT. Two evaluators selected the image with the deepest marginal dye

penetration for each restoration from the occlusal and proximal surfaces on

consensus. The deepest dye penetration depth and total length of the axial cavity

wall from both the occlusal and from the proximal surface were measured

manually using morphometric quantification software by three evaluators

independently. Results concluded that there was no marginal leakage found in five

traditional and one ART restoration. The percentage of silver nitrate penetration

depth from the cervical-proximal site ranged from 10.2-92.6%. There was only a

statistically significant difference observed in measuring total axial wall length

Review of literature from the cervical-proximal site between the three evaluators (P = 0.02). This explanatory investigation showed that the micro-CT was a very useful device for developing a standardized method for measuring marginal leakage from samples obtained in vivo. In combination with 50% (w/v) silver nitrate and 4-hour immersion, marginal leakage along the restoration-tooth tissue interface was accurately and reliably measured.

Abd El Halim S et al.201115 compared the microleakage and adaptation of

Class V cavity preparations restored with three types of glass-ionomer materials as a function of time. A total of 144 sound, freshly-extracted human premolars were used for the study. One clinician prepared all the teeth for Class V-type cavities on the buccal surface of each tooth. The preparations measured 3 mm long, 2 mm wide and 1.5 mm deep, with the gingival margin in dentin and the occlusal margin in enamel. All the prepared teeth were randomly divided into three groups of 48 teeth, according to the type of glass-ionomer material used: Group (A): Ketac

N100 glass ionomer, Group (B): Vitremer glass ionomer and Group (C): Photac Fil

Quick glass ionomer. The restorative materials were used according to their manufacturers' recommendations. The teeth were placed in one increment and photocured for 40 seconds. All of the restored teeth were then stored in artificial saliva. Each group was subdivided into three subgroups according to the testing periods (7, 30, 60 days). Next, they were thermocycled at 5°C–55°C for 100 cycles. The teeth used for the dye penetration test were immersed in 1%methylene blue solution for eight hours. They were then sectioned longitudinally in a buccolingual direction. The extent of dye penetration at the occlusal and gingival margins of each restoration was studied under a stereomicroscope at 25×

Review of literature

magnification. Randomly selected samples from each group were prepared for

scanning electron microscopic evaluation. Dye penetration scores were analysed.

Results concluded that the light-curing nanofilled glass ionomer (Ketac N100)

showed the least microleakage.

Rekha C et al.201216 evaluated and compare the tensile bond strength and

microleakage of Fuji IX GP, Fuji II LC, and compoglass and to compare bond

strength with degree of microleakage exhibited by the same materials. Occlusal

surfaces of 96 noncarious primary teeth were ground perpendicular to long axis of

the tooth. Preparations were distributed into three groups consisting of Fuji IX GP,

Fuji II LC and Compoglass. Specimens were tested for tensile bond strength by

mounting them on Instron Universal Testing Machine. Ninety-six primary molars

were treated with Fuji IX GP, Fuji II LC, and compoglass on box-only prepared

proximal surface. Samples were thermocycled, stained with dye, sectioned, and

scored for microleakage under stereomicroscope. Results concluded that Fuji II LC

and compoglass can be advocated in primary teeth because of their superior

physical properties when compared with Fuji IX GP.

Gupta et al .201217 evaluated the microleakage of nano‑filled resin‑modified glass ionomer restorative in comparison with that of conventional glass ionomer cement (CGIC), and resin‑modified glass ionomer cement (RMGIC). Forty‑five standardized Class V cavity preparations were prepared on sound extracted human molar teeth. Teeth were randomly assigned to three experimental groups of 15 teeth each and restored as follows: Group 1, CGIC; Group 2, RMGIC; and Group 3, nano‑filled RMGI. The specimens were placed in a solution of 2% Rhodamine‑B dye for 24 h at room temperature under vacuum. Staining along the tooth restoration

Review of literature interface was recorded. Study concluded that no material was able to completely eliminate microleakage at enamel, dentin, or cementum margin. Nano‑filled RMGI showed least microleakage compared to other two cements at gingival margins.

Poggio et al.201318 evaluated the microleakage in Class II composite restorations with gingival cavosurface margin below the CEJ (cemento-enamel junction) and restored with different techniques. Filtek TM Supreme XTE Flowable

(3MESPE) + Universal Filtek Supreme XTE (3MESPE), GrandioSO Heavy Flow

(Voco) + GrandioSo (Voco), SDR™ (Dentsply Caulk) + Esthet-X® HD (Dentsply

Caulk), SonicFill (Kerr), Grandio (Voco) was analysed. Fifty human teeth were used. In each tooth two standardized Class II slot cavities (on mesial and on distal surfaces) were prepared: the buccolingual extension of the cavities was 4 mm; the gingival wall was located in dentin/cementum (2 mm beyond the CEJ). The prepared teeth were randomly assigned to 5 experimental groups (of 10 specimens and 20 cavities each) and restored. Group 1: Filtek TM Supreme XTE Flowable

(3MESPE) + Universal Filtek Supreme XTE (3MESPE), Group 2: GrandioSO

Heavy Flow (Voco) + GrandioSo (Voco), Group 3: SDR™ (Dentsply Caulk) +

Esthet-X® HD (Dentsply Caulk), Group 4: SonicFill (Kerr), Group 5: Grandio

(Voco). After thermocycling, the specimens were immersed in a 0.5% basic fuchsine dye solution and incubated at 37°C for 24 hours. The teeth were subsequently sectioned mesiodistally. All specimens were examined at 25× in a stereomicroscope and standardized digital images were obtained. Dye penetration was measured from gingival margins. Study concluded that none of the restorative techniques tested completely eliminated microleakage dye penetration in dentin margins; marginal

Review of literature adaptation in Class II composite restorations with gingival wall below the CEJ varied in both substrates and from different restorative techniques used.

Donmez et al. 201319 investigated the effect of different Er:YAG laser pulse modes on the microleakage of composite resin restorations using self-etch adhesive systems in class V cavities. The teeth were randomly divided into three groups:

Group 1; acid etching, Group 2; Er:YAG laser etching with MSP mode, Group 3:

Er:YAG laser etching with QSP mode. Cavities were restored with a hybrid composite. Standard class V adhesive cavities were prepared on the buccal and lingual surfaces of sound human premolar teeth. The cervical cavity margins were below the CEJ. The teeth were randomly divided into three groups: Group 1; acid etching, Group 2; Er:YAG laser etching with MSP mode, Group 3: Er:YAG laser etching with QSP mode. Cavities were restored with a hybrid composite (Clearfil

sectioned bucco-lingually. Dye penetration was then scored. Study concludes that none of the group did not completely eliminate microleakage, Er:YAG laser etching with QSP mode was better than conventional acid-etching and MSP mode, however, there were no statistically significant differences between them.

Sooraparaju et al. 201420 compared and evaluated the microleakage in class V

lesions restored with composite resin with and without liner and injectable nanohybrid

composite resin. 60 class V cavities were prepared in 30 freshly extracted teeth.

After etching and application of bonding agents these cavities were divided into

three groups: Group A (푛 = 20)—restored with composite resin, Group B (푛 =

20)—flowable composite resin liner + composite resin, and Group C (푛 = 20)—

Review of literature

restored with injectable composite resin. After curing all the specimens were

subjected to thermocycling and cyclic loading. Specimens were stained with 0.5%

basic fuchsin and evaluated for dye penetration. and he concluded that none of the

three materials were free from microleakage. All the three materials showed more

microleakage at gingival margins compared to occlusal margins. Among all the groups

G-aenial Flo showed the least microleakage at the gingival wall.

Diwanji et al.201421 compared the microleakage of glass ionomers

(conventional and resin modified) with that of recently introduced nano-ionomers

Standardized class I and class V cavities were prepared on 120 young permanent teeth. Samples were equally divided into group I (class I restorations) and group II

(class V restorations), and further divided into subgroups. The subgroups were restored with Fuji IX, Fuji II LC, and newly introduced Ketac™ N 100 (KN 100).

Samples were thermocycled and submerged in Acridine dye for 24h. Samples were sectioned to view under fluorescent microscope and evaluated the marginal leakage.

He concluded that Fuji IX showed the maximum microleakage. KN 100 showed minimum leakage, better sealing ability, and was more consistent.

Hussein et al. 20149 investigated the effect of acidic solution on surface roughness and microleakage of tooth-colored restorative materials. A 160 box- shaped cavities were prepared on the buccal surfaces of 160 human molars, and assigned to four groups: Group A restored with Ketac™ Molar Easymix, Group B with Fuji II™ LC, Group C with Ketac™N100, and Group D with Filtek™ Z250, and subdivided into study and control groups (n = 20). Study groups were immersed in lemon juice (pH = 2.79) for 24 h, whilst controlgroups in deionized distilled water. All samples were immersed in 2% methylene blue dye, sectioned into two

Review of literature equal halves for surface roughness, and microleakage tests. and results showed that there was a significant difference in surface roughness of Ketac™ Molar, Fuji

II™LC, and Ketac™N100. No significant difference was found in microleakage of

Ketac™ Molar and Fuji II™LC; however, there were significant differences in the gingival margin of Ketac™ N100, and the occlusal margin of Filtek™Z250.

Giray et al. 201422 evaluate the microleakage of the new glass ionomers

ChemFil™Rock and IonoluxAC in comparison to Fuji IX GP Extra and the composite AeliteTMLS Posterior in permanent teeth. Class V standardised U-shaped cavities were made on a total of 40 freshly extracted teeth and restored with different glass ionomer materials (4 groups of 10 samples each) After thermocycling, the teeth were immersed in 0.5% basic fuchsin for 24h. They were then sectioned in the buccolingual direction. Microleakage was assessed for the occlusal and gingival margins under a microscope at 40x magnification.and he concluded that the cavities filled with a conventional glass ionomer (Fuji IX GP Extra) had significantly less leakage than cavities filled with the new glass ionomers (ChemFil™ Rock and

IonoluxAC), these results do not reflect all the variables present in vivo conditions.

As the in vitro evaluation of new materials does not always reveal their full limitations or possibilities, clinical testing of new systems remains the ultimate proof of effectiveness.

Effat Khodadadi et al.201423 compared the microleakage of flow able resin reinforced glass ionomer (Ionoseal) with other materials used as fissure sealants. In this in vitro study, 50 premolar teeth of human free of any caries were selected.

Fissurotomy was done with fissure bur. The samples were randomly categorized into five groups (Fissurit FX, Fuji II light-cured,Grandio flow, Ionoseal). Ionoseal was

Review of literature assessed by using two methods: with and without etching and bonding agent prior to sealant application. After sealant placement, all surfaces of the teeth except 2 mm area around the sealant margins were covered with two layers of nail polish. The specimens were thermocycled, and they were sectioned after immersing into a 0.5 % basic fuchsine solution. The amount of microleakage was examined by stereomicroscope. And he concluded that By considering isolation difficulties in children and observing high amount of Ionoseal microleakage (without etching and bonding application), the samples need to be etched and bonded like other resin- based materials before Ionoseal placement in order to achieve clinically desirable microleakage outcomes.

Parolia et al.201424 compared the microleakage around class V cavities restored with silorane and dimethacrylate-based composite resins. Teeth were randomly divided into 3 groups depending on the restorative materials used,

Silorane-based composite resin (Filtek P90-SIL), dimethacrylate-based composite resin (Solare P-SOLP) and light-cure glass ionomer cement (GC Fuji II LC -

LCGIC). Standard Class V cavities were prepared on the buccal surface of 60 noncarious human molars. Teeth were randomly divided into 3 groups (n=20) depending on the restorative materials used, Silorane-based composite resin (Filtek

P90-SIL), dimethacrylate-based composite resin (Solare P-SOLP) and light-cure glass ionomer cement (GC Fuji II LC -LCGIC). The restored teeth with these tooth- coloured restorative materials were thermo-cycled and then immersed in 2%

Rhodamine B dye under vacuum pressure for 48 hours. All teeth were bisected longitudinally in a bucco-lingual direction and observed under stereo-microscope at

30X magnification for the evidence of dye penetration. Study concluded that

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Silorane-based composite exhibited least microleakage in restoring class V cavities compared to dimethacrylate-based composite resin and light-cured glass ionomer cement.

Shruthi et al.201525 evaluated the microleakage among conventional, resin modified glass ionomer cements (GIC), and compomer cements in primary teeth.

Teeth randomly divided into three groups. Group A: GC Fuji II; Group B: Vitremer;

Group C: Compoglass F. Forty-five over retained non carious primary molars beyond exfoliation time were collected and randomly divided into three groups (n =

15). Group A: GC Fuji II; Group B: Vitremer; Group C: Compoglass F. A standard

Class V cavity was prepared on the buccal surface of each tooth with no mechanical retention and restored accordingly. Then all the samples were subjected to thermocycling for 250 cycles at different temperatures and covered with nail varnish. Later, samples were immersed in 0.5% methylene blue dye for 24 h. Teeth were sectioned buccolingually through the center of the restoration and studied under a stereomicroscope for dye penetration. and concluded that none of the three

GICs was free from microleakage.

Rengo et al.201526 analysed Class V composite restorations marginal leakage measurements obtained with microcomputed tomography (micro-CT) and scanning electron microscopy (SEM) observations. Tooth restored using Optibond

FL (Kerr, Orange, CA, USA) and Premise Flowable (Kerr). Class V cavities were prepared on 10 human molars and restored using Optibond FL(Kerr, Orange, CA,

USA) and Premise Flowable (Kerr). Sealing ability was evaluated by assessing silver-nitrate penetration depth along enamel and dentin margins. Leakage was quantified using a scoring system. Micro-CT analysis provided 502 cross-sectional

Review of literature images for each tooth. Microleakage evaluation was performed first on three cross- sections corresponding to the sections examined by SEM, then on all 502 of the obtained micro-CT images. SEM observations were performed first at 20 magnification, then, if showing a zero score, at 80X magnification. Results shows

Micro-CT presents as a valid, non-destructive in vitro method to quantitatively evaluate marginal leakage of adhesive restorations.

Niranjan et al.201627 investigated microleakage of three different bases under composite resin in sandwich technique using dye penetration and dentin surface interface using scanning electron microscope (SEM). Teeth were divided into 3 groups. Group 1 ‑ glass ionomer cement (GIC); Group 2 ‑ mineral trioxide aggregate (MTA); Group 3 ‑ Biodentine™ was placed as a base under composite.

Sixty extracted deciduous molars were stored in distilled water and Class I cavities with a width of about one‑fourth of intercuspal distance and a depth of 0.5–1 mm below the dentino‑enamel junction was prepared without bevels. In Group 1 ‑ glass ionomer cement (GIC); Group 2 ‑ mineral trioxide aggregate (MTA); Group 3 ‑

Biodentine™ was placed as a base under composite. Teeth were longitudinally sectioned in two halves, through the centers of the restoration, immersed in 2% methylene blue and microleakage was evaluated under stereomicroscope and surface interface between base and dentin was evaluated under SEM. Study concluded that

Biodentine™ exhibits superior marginal sealing ability as well as marginal adaptation under composite resin as compared to MTA and GIC.

Sakri et al.201628 evaluated the impact of bulk or incremental curing of hybrid composite resin with different intermediate layers on interfacial microleakage. The recently extracted, sixty noncarious human mandibular molars

Review of literature were selected for the study. The standardized mesio‑occluso‑distal cavity with the occlusal cavity of 2 mm depth, 3 mm buccolingual width and proximal box dimension of 4 mm buccolingual width and 2 mm depth was prepared on all experimental teeth. The samples were divided into six groups of ten each. Group I was without an intermediate layer. Group II and III had 1 mm flowable composite liner, with incremental and bulk curing cycle, respectively. The Group IV, V, and VI had a self‑cure composite liner with incremental and bulk curing. The teeth subjected to thermocycling and kept in 0.5% basic fuchsine dye for 24 h. The teeth were sectioned and observed under a stereomicroscope to grade them according to the extent of microleakage. Within the limitation of the study, it was concluded that intermediate flowable composite with incremental curing was better suited to reduce microleakage.

Motevaselian et al.201629 compared microleakage of three resin bonding agents namely a universal adhesive, two-step self-etch system and two-step total- etch system. Class V cavities were prepared in the buccal or lingual surfaces of the teeth with occlusal margins in the enamel and gingival margins in dentin. The teeth were then randomly divided into four groups. Group A: Adper Single Bond 2, group

B: Clearfil SE Bond, group C: Scotchbond Universal adhesive (self-etch) and group

D: Scotchbond Universal adhesive (total-etch). This in vitro, experimental study was conducted on 68 human molars. Class V cavities were prepared in the buccal or lingual surfaces of the teeth with occlusal margins in the enamel and gingival margins in dentin. The teeth were then randomly divided into four groups of 17.

Group A: Adper Single Bond 2, group B: Clearfil SE Bond, group C: Scotchbond

Universal adhesive (self-etch) and group D: Scotchbond Universal adhesive (total-

Review of literature etch). The teeth were then restored using different bonding agents and a microhybrid composite resin. The specimens were then subjected to 1000 thermal cycles between

5-55°C. The entire restoration surface except for 1mm around the margins was coated with nail varnish. The teeth were immersed in 2% methylene blue for 24 hours and sectioned longitudinally in a buccolingual direction and observed under a stereomicroscope to determine microleakage. The teeth were then restored using different bonding agents and a microhybrid composite resin. Results shows different adhesive systems tested in this study showed similar microleakage at the enamel and dentinal margins.

E. Ozel et al.201630 investigated how two cavity-filling techniques affect microleakage in class II resin restorations prepared with Er:YAG laser and diamond bur. Samples were divided into 4 groups. Group-1 Herculite XRV Ultra-burprepared cavity(bp), Group-2 Herculite XRV Ultralaser- prepared cavity(lp), Group-3

(SonicFill-(bp), or Group-4 SonicFill-(lp). For Groups 2 and 4, cavitieswere prepared by using an Er:YAG laser with a wavelength of 2.94mm, output power of

200 mJ/pulse, and repetition rate of 20Hz. Teeth were restored with a one-step, self- etch adhesive material (OptiBond All-in-One), a nanohybrid composite (Herculite

XRV Ultra), and a bulk-fill composite (SonicFill) according to the manufacturer’s instructions. Five teeth from each group were chosen for microleakage investigation and two teeth for scanning electron microscope evaluation. Results shows cavities prepared with Er:YAG laser exhibited greater microleakage than those conventionally prepared with bur at both occlusal and cervical margins in this study, regardless of restorative material. At the same time, cervical regions exhibited significantly higher microleakage than occlusal ones in all groups tested. The bulk-

Review of literature fill resin composite (i.e., SonicFill) thus reduced microleakage compared with the nanohybrid composite for both occlusal and cervical margins.

Govil et al. 20162 evaluated the microleakage of four tooth coloured

restorative materials in 80 restored Class V cavities. 40 human premolar teeth

samples were selected and eighty standardized class V cavities were prepared on

them. These were further divided into four groups, each group comprising of 20

prepared cavities, and were restored with four experimental tooth colored

restorative materials (Glass ionomer cement, Resin Modified Glass ionomer

cement, Hybrid composite resin and Nano composite resin) respectively. The

restored teeth were subjected to thermocycling for 500cycles in 37°C neutral

bath,5ºC cold water bath and 55°C hot water bath followed by 2% methylene blue

dye penetration for 24 hours at room temperature. Each crown was then sectioned

bucco-lingually and the sections were stored in 100% humidity before being

examined under stereomicroscope (16 x magnification) to measure the depth of

dye penetration. The results showed that minimal microleakage in Group II(Fuji

IXGP) followed by Group IV (Z350), Group III(Z100) and Group I(Fuji II LC)

showed maximum microleakage.

Somani et al. 201631 determined the microleakage of the 6th, 7th, and 8th generation dentin bonding agents. Forty‑five extracted human premolars were taken for the study. Standardized Class V cavities were prepared on all the teeth. The samples were divided into three groups according to the generation of bonding agent used. Group I was bonded with the 6th generation, Group II with the 7th generation, and Group III with the 8th generation dentin bonding agent. All the Class V

Review of literature preparations were restored with a nano‑ceramic composite restorative (Ceram X).

The samples were then thermocycled between 5 and 55 ± 2°C for 100 cycles and immersed in 2% methylene blue for 48 h for evaluation of microleakage under a stereomicroscope. The results concluded that the 8th generation dentin bonding showed statistically significant results in terms of lesser microleakage as compared to the 6th and 7th generation dentin bonding agents.

Bollu et al.201632 evaluated microleakage in Class V cavities which were restored with Resin Modified Glass Ionomer Cement (RMGIC), Giomer and Nano-

Ionomer. This in-vitro study was performed on 60 human maxillary and mandibular premolars which were extracted for orthodontic reasons. A standard wedge shaped defect was prepared on the buccal surfaces of teeth with the gingival margin placed near Cemento Enamel Junction (CEJ). Teeth were divided into three groups of 20 each and restored with RMGIC, Giomer and Nano-Ionomer and were subjected to thermocycling. Teeth were then immersed in 0.5% Rhodamine B dye for 48 hours.

They were sectioned longitudinally from the middle of cavity into mesial and distal parts. The sections were observed under Confocal Laser Scanning Microscope

(CLSM) to evaluate microleakage. Depth of dye penetration was measured in millimetres and he concluded that Nano-Ionomer and RMGIC showed significantly less leakage and better adaptation than Giomer and there was no statistically significant difference between Nano Ionomer and RMGIC.

Rajisha KR et al. 201633 evaluated the effect of two curing modes on the microleakage of a bulk-fill flowable composite resin, Surefil SDR Flow.

Standardized class V cavities were prepared on buccal and palatal surfaces of each tooth and restored with the flowable composite, Surefil SDR Flow. Based on the

Review of literature curing protocol the teeth were divided into two groups. Extracted maxillary premolars were used for this study. Standardized class V cavities were prepared on buccal and palatal surfaces of each tooth and restored with the flowable composite,

Surefil SDR Flow. Based on the curing protocol the teeth were divided into two groups. Restoration on the buccal surface of the teeth were subjected to low power polymerization, were grouped as the group I and the restorations on the palatal surfaces were subjected to soft start polymerization and were grouped as group II.

All the samples were immersed in 0.5% basic fuchsin solution and was subjected to microleakage assessment. The samples were then sectioned, evaluated under a stereomicroscope and scored for microleakage. Analysis of variance (ANOVA) has been used to find the significance of study parameters between the groups and concluded that the soft start polymerization mode offered a distinctive advantage over the low power curing protocol using Bluephase curing unit.

Tavangar M et al.201734 compared the microleakage of class V cavities restored with the newly introduced Embrace WetBond class V (EWC) composite resin and conventional Opallis composite resin. In this in vitro study, class V cavities were prepared on 30 extracted bovine incisors, with the gingival floor and the coronal margin of the cavities 1 mm apical and coronal to the cementoenamel junction (CEJ) respectively. The cavities measured 3 mm in length, 2 mm in width, and 1.5 mm in depth. The teeth were randomly divided into two groups. In group I, the cavities were restored with Opallis composite resin in association with ExciTE adhesive system (total-etch); in group II, the EWC composite resin was used for restorations. After 500 thermocycling procedures, the teeth were immersed in 0.5% fuchsin solution for 24 hours. Then, the samples were placed within a polyester

Review of literature model and sectioned in the buccolingual direction. The samples were evaluated under a stereomicroscope at ×30 for the penetration of dye. The enamel and dentin margins were evaluated separately. The results concluded that Despite the high speed and the short process of restoration with Embrace WetBond, it is not a reliable restorative material for class V cavities due to its inadequate marginal seal.

Lagisetti et al. 20175 evaluated and compared the sealing ability of

EndoSequence BC RRM fast set putty, Proroot mineral trioxide aggregate (MTA), and

Zirconomer in the repair of furcal perforation by measuring dye leakage under stereomicroscope. A standard access cavity was made on forty‑eight extracted mandibular and maxillary first molars followed by creating a furcal perforation in the center of the pulp chamber by using No. 4 round bur (creating a perforation of 2 mm diameter). Teeth were categorized into 4 groups containing 12 samples in each group based on material used for furcation repair. Group 1 – Endosequence BC

RRM‑fast set putty; Group 2 – Zirconomer; Group 3‑MTA (positive control); Group

4 – negative control. All groups were covered with two layers of clear varnish except for 2 mm around the perforation region. All the teeth were immersed in 2% methylene blue dye for 48 h for dye penetration. Teeth were sectioned buccolingually using a diamond disk. The sectioned teeth were examined under stereomicroscope with ×10 magnification for dye penetration and results showed that

Endosequence and MTA showed less microleakage hence can be used as furcation repair materials. Due to higher microleakage, Zirconomer should be avoided as furcation repair material. Due to its favorable cost, ready availability, and almost similar outcome as bioceramics, MTA is considered as an alternative to Endosequence and is the gold standard in furcation repair.

Review of literature

Kathal et al. 201735 evaluated and compared the microleakage of three different restorative cements, namely zirconomer, amalgomer CR, and conventional glass ionomer cement (GIC, type II). A total of 45 human noncarious primary molars were selected. The selected teeth were extracted for the reason of overretention or orthodontic purpose. Total samples were divided into three groups:

15 samples in each group – group I: zirconomer (Shofu Inc., Kyoto, Japan), group

II: amalgomer CR (Advance Health Care, Ltd., Tonbridge, UK), and group III: conventional GIC (Medicept Type II, Ltd., India). Hand scalers were used to remove calculus if present on the root surface and the teeth were stored in glass container containing normal saline. In all the samples class I cavity was prepared on the occlusal surfaces of the extracted noncarious primary molars using high-speed hand piece. From the previously divided three groups, i.e., groups I, II, and III, each group contains 15 teeth. All teeth were restored with either of the three restorative materials. Restored samples from the three groups were then subjected to thermocycling. The teeth were immersed in an aqueous solution of methylene blue for 48 hours and then sectioned longitudinally in a buccolingual direction through the center of both cavities using a low-speed diamond saw. The dye penetration depth along the occlusal margin was evaluated for each group. Dye penetration scores were analyzed by two calibrated and blinded evaluators and concluded that none of the material was free from microleakage. Although the new materials have certain advantage of strength, they lack microleakage.

Samanta et al. 201736 compared and evaluated the microleakage in class V cavity filled with flowable composite resin, glass ionomer cement and cention. Class

V cavities were prepared in 30 freshly extracted teeth.Teeth were randomly assigned

Review of literature into three experimental groups (n = 10).Group 1 -Restored with Flowable

Composite. Group 2-Restored with Glass Ionomer cement.Group 3- Restored with

Cention N. All the specimens were subjected to thermocycling. Specimens were stained with 0.1% Methylene Blue Dye and evaluated for dye penetration under stereomicroscope. The results concluded that All materials showed some microleakage at the cervical margin of restoration. However, Group 3(Cention N) exhibited lowest microleakage.

Dennis et al.201737 evaluated the effect of microleakage in class V cavity using self-adhering flowable composite/self-adhesive with the addition of acid etch.

The teeth were prepared in class V cavities and filled with self-adhering flowable composite, total-etch adhesive system and flowable composite resin. All the teeth were randomly assigned into 3 groups. Study was conducted on extracted 27 lower premolars. The teeth were prepared in class V cavities and filled with self-adhering flowable composite, total-etch adhesive system and flowable composite resin. All the teeth were randomly assigned into 3 groups: Group 1: 9 cavities restored with self-adhering flowable composite without etching, Group 2: 9 cavities restored with self-adhering flowable composite with etching only and Group 3: 9 cavities restored with flowable composite with total etch system. After being polished, the teeth were thermocycled 200 times, then it was coated with nail polish and immersed in methylene blue for 24 hours. They were sectioned longitudinally and using the stereomicroscope with 20 times magnification dye penetration was measured. The results concluded that Self-adhering flowable composite alone was enough to establish good marginal sealing with enamel margins but was inadequate to establish good marginal sealing with dentin margins.

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Athanasios Synarellis et al.201738 compared the degree of microleakage on enamel and dentin margins of class V cavities prepared with either a high-speed drill or an Er,Cr:YSGG laser (2780 nm) and to associate their use with a beveling method for the margin. Sixty bovine incisors were randomly distributed into three groups.

Group 1 (G1) cavities were laser prepared and bur beveled, group 2 (G2) cavities were bur prepared and beveled, while cavities of group 3 (G3) were laser prepared and beveled. Cavities were restored with selective enamel etching, using the same bonding agent and nano-hybrid resin composite for all groups. After thermocycling, microleakage was assessed using a methylene blue dye penetration method. Results shows The conventional cavity preparation method seems to perform better in terms of microleakage than the Er,Cr;YSGG laser. Laser-prepared cavities could perform better in terms of microleakage if an additional step of enamel bur-beveling is performed prior to restoration.

Shathi et al.201739 compared the marginal microleakage of ormocer

restorative material with that of giomer in vivo. The results showed that no

microleakage (score 0) was detected in 15 ormocer and 5 giomer restorations. The

remaining restorations were associated with dye penetration which was due to gap

formation as seen in stereoscopic and scanning electron microscopic observations.

The differences between ormocer and giomer restorative materials in respect to dye

penetration were statistically significant. It can be concluded that ormocer

restorative material shows less microleakage than that of giomer.

Khamverdi et al.201740 evaluated the microleakage in class V composite resin restorations using two bulk filled resin-composites and one conventional composite. In this study, in the buccal and lingual surfaces of 30 extracted

Review of literature premolars, V-shaped cavities were prepared and samples using a single bond bonding were restored in three groups as follows: Group 1: Composite bulk filled

(Filtek). Group 2: Composite bulk filled (X-tra base). Group 3: conventional composite Grandio. After thermocycling of the samples, microleakage was evaluated on occlusal and gingival of the restorations by dye penetration technique under a microscope with a magnification of 20. The results of this study showed that the use of Bulk filled composites rather than conventional composites in class V cavities expanded on the root surface reduced leakage. But there was no statistical difference between Bulk filled composites (X-tra base and Filtek).

Bansal et al.201741 measured the microleakage of class V glass ionomer restorations over two different periods of enamel microabrasion. Microabrasion treatment was performed with Opaluster (Ultradent Product Inc.,South Jordan, UT,

USA) for 0 (control no treatment), 60 and 120 s. the teeth were classified into six groups (n = 20). Microabrasion treatment was performed with Opaluster (Ultradent

Product Inc., South Jordan, UT, USA) for 0 (control no treatment), 60 and 120 s.

Then, teeth were thermocycled between 5°C and 55°C, immersed in rhodamine B solution (24 h), and sectioned longitudinally in buccolingual direction. Dye penetration was examined with stereomicroscope (×10). Microleakage scores were statistically analyzed. Study concluded that the least microleakage scores were observed in occlusal margins of control groups (without microabrasion). Moreover, in both restorations, the microleakage scores in occlusal margins were higher than gingival margins.

Mohita Gupta et al.201742 evaluated microleakage associated with three

placement techniques for compomer restorations in primary molars. This

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experimental study assessed the microleakage associated with bulk‑fill,

horizontal‑incremental, and oblique‑incremental compomer placement techniques.

Result shows microleakage was observed with all the three techniques but was

comparatively lower with the incremental placement techniques. The

oblique‑incremental technique offered the least microleakage.

Paul George et al.201843 evaluated the microleakge of a newly introduced restorative material, Cention N, with the commonly used posterior restorative materials. Teeth were randomly assigned into five experimental groups and restored using amalgam, GIC, packable composite, cention with adhesive and without adhesive.50 single rooted premolars free of caries or any other defects and extracted for orthodontic reasons were chosen for the study. Subsequently class 2 cavities were prepared and teeth were randomly assigned into five experimental groups (n =

10) and restored using amalgam, GIC, packable composite, cention with adhesive and without adhesive,respectively. All the specimens were subjected to thermocycling. Specimens were stained with 0.1% Methylene Blue Dye and evaluated for dye penetration under stereomicroscope. The study therefore showed

Cention N to have lesser microleakage compared to GIC and composite restorations, thereby having better sealing ability.

Hussin et al.201844 evaluate the in vitro microleakage of new modified glass ionomer cement (GIC) nanozirconia‑silica‑hydroxyapatite

(GIC‑nanoZrO2‑SiO2‑HA) hybrid material by comparing the depth of microleakage with conventional GIC (Fuji IX). Forty samples of standardized oval‑shaped cavity preparation (4 mm × 3 mm × 2 mm) on buccal or lingual surfaces of freshly extracted human premolar and molar teeth were prepared. The samples were divided

Review of literature in two groups (n = 20) by simple random sampling method and restored with the new modified GIC‑nanoZrO2‑SiO2‑HA hybrid material and Fuji IX (control), respectively; following the manufacturer’s recommendations. All samples were then submitted to thermocycling (500 cycles at 5°C–55°C). The external surfaces of each tooth were coated with nail varnish except a 1 mm wide margin surrounding the restoration. Samples were then immersed in 2% methylene blue at room temperature for 24 h before rinsed under running water. Each sample was sectioned mesiodistally before microleakage evaluation was done using a stereomicroscope under × 20 magnifications and graded accordingly. and concluded that the new modified GIC‑nanoZrO2‑SiO2‑HA hybrid material was found to have more microleakage than conventional GIC.

Nagy et al.201845 evaluate and compared the marginal seal of Class V composite restored with different cavosurface margins. The teeth were divided into two main groups: group I, cavosurface angle was 90° butt‑joint; group II, beveled enamel and dentin cavosurface margins. Each group subdivided into three subgroups: group A, restored with Filtek bulk‑fill flowable composite. Group B, restored with Filtek bulk‑fill posterior composite. Group C, restored with Filtek

Z250XT Universal composite. Restorations were cured with LED light curing unit.

A standardized Class V cavity, 4 mm wide, 3 mm high, and 3 mm deep, were prepared on the buccal surface of 60 extracted molars with the occlusal margin located in enamel and the gingival margin located in dentin‑cementum 1.0 mm below the cementoenamel junction. The teeth were divided into two main groups: group I, cavosurface angle was 90° butt‑joint; group II, beveled enamel and dentin cavosurface margins. Each group subdivided into three subgroups: group A, restored

Review of literature with Filtek bulk‑fill flowable composite. Group B, restored with Filtek bulk‑fill posterior composite. Group C, restored with Filtek Z250XT Universal composite.

Restorations were cured with LED light curing unit. All specimens were stored in

37°C and 100% humidity for 24 h, thermo cycled for 600 cycles with baths held between 5 and 55°C, a dwell time of 30 s and a transfer time of 10 s. The restored coronal portion were cut 3 mm beyond the cementoenamel junction, each specimen were sectioned in bucco–lingual direction through the center of each restoration resulting in two sections. The cut surfaces were examined at the occlusal and gingival margins using a stereomicroscope at 30× magnification with an attached digital camera.results shows There was significant inverse correlation between flowable bulk‑fill and conventional composite and high significant between occlusal and gingival margin and there is no need for a bevel in Class V carious lesions.

Patel et al.201846 compared the marginal sealing of three different bulk‑fill

composite restorations of Class II cavities under in vitro conditions. Class II

cavities were prepared and restored using Filtek Bulk Fill (Group I), Tetric

N‑Ceram Bulk Fill (Group II) and X‑tra Fil Bulk Fill (Group III) composite

materials. Depth of dye penetration along the lateral walls of each specimen was

evaluated under stereomicroscope, and marginal gap was evaluated under scanning

electron microscope and concluded that Filtek Bulk Fill composite material

showed least microleakage and better marginal adaptation.

Salman et al.201947 evaluated the adaptability of new novel restorative material Nano‑ionomer with resin‑modified glass ionomer, Zirconomer, Giomer to tooth surface by measuring the degree of microleakage at gingival and occlusal restorative margins of Class V cavities and compare the same among the groups

Review of literature using stereomicroscopic study. A total of 60 Class V cavities were prepared with occlusal margin in enamel, and the cervical margin in dentin and cementum of sound extracted premolars. Restorations were randomly assigned to one of the four groups (n = 15) and were restored with various type of glass ionomers

(resin‑modified glass‑ionomer cements [RMGIC], Zirconomer, Giomer,

Nano‑ionomer), respectively. Specimens were thermocycled, immersed in

Methylene blue dye, sectioned longitudinally and analyzed for leakage at the occlusal and cervical interfaces. Analysis of variance test, followed by post hoc

Bonferroni Test was used to determine the inter‑ and intra‑group difference and

Paired t‑test was used to determine the significant difference at enamel and cementum margins. It was concluded that all the restorative materials tested shows microleakage to an extent. Nano‑ionomer was better than the other three types of glass ionomers in reducing the microleakage.

Mazumdar et al.201948 compared the microleakage of three different direct restorative materials such as amalgam, glass ionomer cements [GICs], and Cention

N in Class II restorations using stereomicroscope. With the help of a 5mm diameter straw, already cut to 3 mm in length, cylindrical plastic moulds were prepared.

Restorative materials were inserted in different moulds Composite resin and cention

N were polymerized with LED. Moulds filled with materials were covered with a glass slab to provide a flat surface. All the samples were stored in distilled water for

24 hrs. The samples so prepared were divided into groups as follows and subjected to experimentation. The samples were randomly tested with microardness indentor.

Results of the study shows CN a newer restorative material displayed minimum microleakage compared to Amalgam and GICs.

MATERIALS & METHODS Materials and Methods

MATERIALS/INSTRUMENTS/EQUIPMENTS USED IN THE STUDY a) Conventional glass ionomer cement (GC Fuji Type II, GC Corporation,

Tokyo, Japan) b) Zirconomer (Shofu Inc., Kyoto, Japan) c) Ionoseal (VOCO GmbH, Cuxhaven, Germany) d) Beautifil Giomer (Shofu, Kyoto. Japan) e) Cention N (Ivoclar Vivadent, Liechtenstein, Germany) f) Plastic instrument (GDC fine crafted dental Pvt.Ltd, Hoshiarpur, India) g) Agate spatula (API, Delhi, India) h) Mixing paper pad (3M ESPE, St. Paul, Minneapolis) i) Nail polish varnish (Galaxy Nail ColourTM, Vasai, Mumbai) j) Thermocycling chamber k) 50% wt silver nitrate solution (High purity laboratory chemicals Pvt Ltd,

Mumbai, India) l) Micromotor hand piece (Straight hand piece, NSK, Korea) m) Diamond disc (SS White, New Jersey, USA) n) Stereomicroscope ( Sz61, Olympus America Inc, Center Valley, PA, USA) o) Photographic developing solution (Dental X-Ray Developer, Kodak,

Rochester, New York, USA) p) Distilled water ( High purity laboratory chemicals Pvt Ltd, Mumbai, India) q) Digital caliper (Mitutoyo; Suzano, Brazil) r) Light microscope (Carl Zeiss, Gottingen, Germany) s) Carbide bur (Dia-Burs, Mani Inc, Tochigi, Japan)

Materials and Methods

METHODOLOGY

Specimen selection

Forty caries free human permanent maxillary premolar of comparable dimensions extracted for orthodontic purposes were selected for the study to evaluate the microleakage. Specimens with cracks, and restorations were excluded.

Specimens were examined by transillumination and light microscope (Carl Zeiss,

Gottingen, Germany) (4X) to exclude teeth exhibiting enamel fractures as these might allow dye penetration.

Specimen preparation

Surface debridement of the specimen was done with hand scaling instrument, thoroughly cleaned and stored in distilled water (High purity laboratory chemicals Pvt Ltd, Mumbai, India) for 24 hours at room temperature.

Standardized class V cavities of length 4mm, depth 2mm, width 4mm mesiodistally were prepared on the buccal aspect of the specimen. Dimensions were standardized by measuring with digital vernier caliper. The cavity preparation was done using a no.245 carbide bur (Dia-Burs, Mani Inc, Tochigi, Japan), used with high speed airotor and adequate water spray coolant by the same operator to eliminate the operator variability. Bur was replaced after every five cavity preparations.

Materials and Methods

Restorative procedure

The prepared specimens were randomly divided into five experimental groups of eight specimens each (n=8) and the prepared cavities were restored with five different tooth coloured restorative materials, namely,

Conventional GIC (GC Fuji Type II, GC Corporation, Tokyo, Japan), Zirconomer

(Shofu Inc., Kyoto, Japan), Giomer (Shofu, Kyoto, Japan), Cention N (Ivoclar

Vivadent, Liechtenstein, Germany), Ionoseal (VOCO GmbH, Cuxhaven, Germany)

Groups Restorative materials

Group I Class V cavities restored with Conventional GIC

Group II Class V cavities restored with Zirconomer

Group III Class V cavities restored with Giomer

Group IV Class V cavities restored with Cention N

Group V Class V cavities restored with Ionoseal

All the restored specimens were subjected into artificial aging by thermocycling. Specimens were immersed in a thermocycling chamber between 5°C and 55±2°C for 500 cycles with dwelling time of 15 seconds. All the specimens were coated with nail polish varnish (Galaxy Nail ColourTM, Vasai, Mumbai) except on restorative material and tooth structure 1mm from cavosurface margins. Then the specimens were immersed in 50% wt silver nitrate solution (High purity laboratory chemicals Pvt Ltd, Mumbai, India) for 6 hours in a dark container at room temperature for dye penetration. The silver impregnated specimens were then washed under running water, immersed in a photographic developing solution

Materials and Methods

(Dental X-Ray Developer, Kodak, Rochester, NY, USA) and exposed to fluorescent light for 12 hours and thoroughly rinsed with distilled water.

Microleakage analysis

Specimens were sectioned buccolingually through the restoration using diamond disc (SS White, New Jersey, USA) in a low speed micromotor handpiece

(Straight hand piece, NSK, Korea) and examined under stereomicroscope (Sz61,

Olympus America Inc, Center Valley, PA, USA) at 30 X magnification to assess the micro leakage. The evaluation of leakage was made with a three point severity scale as described by Araujo et al. [2001] and Munro et al. [1996].

SCORE CRITERIA

 No microleakage 0  No dye penetration

 Microleakage observed only at the cavity wall of enamel

1  Dye penetration through the cavity margin reaching the enamel or

cementum

 Microleakage observed at the cavity wall of dentin but not on the

2 cavity floor

 Dye penetration through the cavity margin reaching the dentin

 Microleakage observed on the cavity floor 3  Dye penetration through the cavity margin reaching the cavity floor

Materials and Methods

Statistical analysis

The results of microleakage scores were subjected to statistical analysis using Statistical Package for Social Sciences (SPSS) version 20.0. The mean and standard deviation of microleakage scores of five study groups was compared using one way analysis of variance (ANOVA) followed by post hoc

Tukey HSD test and non-parametric Kruskal-wallis test to determine the significant difference at occlusal and gingival margin. P< 0.05 will be considered to be statistically significant.

RESULTS & OBSERVATIONS Results & Observations

The results were tabulated and statistically analysed by using Kruskal–Wallis analysis of variance for multiple group comparison followed by tukey HSD test. The mean and standard deviation of occlusal scores are tabulated in Table 1. The mean and standard deviation of gingival scores are tabulated in Table 2. Distributions of the microleakage scores according to all test groups and margin location, i.e. the occlusal margin (enamel) and the gingival margin (dentin), are shown in Table 3.

All the tested groups shows microleakage around the margins. Results showed that there was a significant difference between the average microleakage in all the five groups (p ≤0.05). The maximum microleakage is for Conventional Glass

Ionomer cement (Group I) and the lowest microleakage relates to Ionoseal (Group

V) in both occlusal and gingival margin.

Microleakage at occlusal and gingival margin is significant (p ≤0.05). In each group, micro leakage at Gingival margin was significantly more compared to the occlusal margin of the restoration.

The inter-group comparison of occlusal and gingival scores of all five study group was done by post hoc Tukey HSD test that showed a highly significant difference between Group I And Group V. The microleakage score is highest for group I (conventional GIC) and least for group V (ionoseal). The order of microleakage from minimum to maximum, IONOSEAL < CENTION N < GIOMER

< ZIRCONOMER < CONVENTIONAL GIC respectively.

The gingival mean rank of Group I - 30.75, Group II - 27.25, Group III -

20.50, Group IV -13.63, Group V - 10.38. Degree of freedom (df) for microleakage using Kruskal–Wallis test was χ2 = 3.654, df = 4.

Results & Observations

The occlusal mean rank of Group I - 30.50, Group II - 22.75, Group III -

19.25, Group IV -16.00, Group V - 9.00. Degree of freedom (df) for microleakage using Kruskal–Wallis test was χ2 = 5.650, df = 4.

Tukey HSD test was applied for pairwise comparision of the significance in microleakage scores between the experimental groups studied listed in table 4(b) and table 5(b) for gingival and occlusal margin respectively .

Thus the results obtained for the study shows maximum microleakage is seen in Conventional GIC and minimum microleakage seen in Ionoseal, a resin reinforced light cure glass ionomer composite.

DISCUSSION Discussion

The important criteria to improve the prognosis by increasing the durability of the restoration is to prevent microleakage, it is achieved by proper adhesion of the restorative material to tooth structure.47 Because of the constant increase in esthetic demands, tooth colour restorative material have been the common choice for restoration of class V cavitites. Formation of interfacial gaps is the major defect of a restorative material which develop as a result of long term thermal and mechanical stress over the restoration. These stresses may alter the thermal and physical property of the material. These dimensional changes in the restoration can lead to microleakage which is a matter of concern because it can lead to hypersensitivity, formation of secondary caries, staining at the margins and pulpal pathosis.20,39

Microleakage is used as a criteria to predict the performance of a restorative material.47 The morphology of class V cavities with margins partly in enamel and partly in dentin/cementum presents a challenging condition for the restorative material. In the present study, noncarious Class V restorations were chosen for evaluation, because that the preparation of Class V cavities is minimal and their restoration is relatively easy, thereby reducing technique-sensitivity and operator- related variability. Secondly, Class V cavities have margins located both in enamel and in dentin. Moreover, class V cavities have high configuration factor (C-Factor).

C-Factor is the ratio of bonded to the unbounded surface area. Class V restorations has high C-Factor (5) which is the reason for the internal bond disruption as well as microfissures around the restoration and cavity walls.

At present, tooth coloured restorative materials recommended to restore class

V cavities are Glass ionomers, Zirconomer, Giomer, ionoseal, Cention N. One of the important property of the ideal restorative material is to resist the microleakage in

Discussion and around the restoration.22 According to Yammazaki et al in 2006,Evaluating the leakage of bacterial fluid is the method most commonly used for assessing the sealing efficiency of the restorative system. A study by Castro et al 2002, stated that, importance of maintaining the marginal seal of the restoration is to avoid the formation of secondary caries, marginal discolouration and post restorative sensitivity. The correlation between marginal leakage and type of restorative materials used in restorations has been critically evaluated both in clinical and laboratory experiments. Because of less clinical data and definitive clinical findings, laboratory microleakage studies are a most accepted method of testing and evaluating the restorative materials for marginal leakage.

In order to prevent the ingress of contaminants and bacterial products into the restoration, creation of perfect marginal seal is an important criteria.

Replacement of lost peripheral dentin is a primary goal to attain a proper margin in restoration-dentin interface.2

Due to the differences in coefficient of thermal expansion between the teeth and restorative material, thermal changes could be an most important considerable factors for effective marginal seal. In order to simulate the temperature changes that take place in oral environment and stress at a marginal seal, it is necessary to apply thermocycling procedure in microleakage studies.49

In thermocycling procedure, two temperature ranges are used. The upper limit of 45-60˚c and lower limit of 4-15˚c. Many authors including Phillips and

Peterson (1996) applied 15 ° and 45 ° to heat cycles, while the study by Grieve and his colleagues (1993) have recommended thermocycling at 5 and 55 degrees. Hot

Discussion and cold baths for 10, 15, 30, 60 or 120 seconds are recommended for immersion of the specimens to simulate oral environment. According to Diwanji et al, thermocycling regimen provides thermal stresses by variation in temperature.

Material reaches thermal equilibrium only on resting bath. This variation likely to increase the leakage by inducing the stress over the material.21 Harper et al. (1980) showed that the actual thermal changes in the mouth are relatively small. And real- time results are obtained when the short duration to be exposed to the whole heat and between the two chambers, enough time should be allowed to sample to return body temperature.50 Stress have been occurred during the process of the thermocycling due to a difference in coefficient of thermal expansion of tooth structure at the interface between the tooth restoration and restorative materials.

According to ISO 11405, the use of 500 thermal cycles between 5°C and 55°C is considered to be suitable to simulate short-term aging of dental materials.51 Thermal cycles ranging between 200 and 1000 were used in some studies (Bertrand et al.,2006; sungertekin and oztas,2010). In this study, the samples are subjected to thermocycling between 5°C and 55±2°C for 500 cycles with dwelling time of 15 seconds.

Several studies have proposed different methods to evaluate the microleakage. Methods include the dye penetration, dye extraction, radioactive isotopes infiltration, acetate peel technique, bacterial leakage, neutron activation analysis, stereomicroscopic analysis, micro-computed tomography, confocal laser scanning microscopy, optical coherence tomography. All these accepted methods come with both advantages and disadvantages. The dye penetration assay using coloured agents and observed under stereomicroscope is the most commonly used

Discussion technique. Despite the controversies, dye penetration studies still remains the best method to evaluate the sealing ability of the materials. It has several advantages over other methods includes, no reactive chemicals were used along with any radiation.

Secondly, it is highly feasible and easily reproducible.47Commonly used stained solutions are, aniline blue, eosin, erythrosine, fluorescein, methelene blue, indian ink, silver nitrate and basic fuschin. 50% weight silver nitrate dye was selected in the study, because it has been accepted as an ideal method for measuring both microleakage and nanoleakage.52

The silver ion is very small 0.059 nm-diameter when compared to the size of a typical bacterium which is 0.5-1.0 μm. Hence it has more penetration and serves as a test material to detect microleakage.53 Edan and others stated that a four hour immersion in a 50% silver nitrate solution allowed accurate and reliable measurements of microleakage.14

The main advantages of silver nitrate dye are the following

1. Easily penetrates water compartment of the tooth

2. Does not react with hard tissues of the tooth

3. Particle size is comparable to the size of micro organisms

4. It is readily detectable under visible light

The limitations of a dye penetration method

1. Results are subjectively evaluated; hence operater expertise is needed

2. Destruction of specimen is necessary

Discussion

In this study, the samples are immersed in 50% wt silver nitrate solution for

6 hours in a dark container at room temperature for dye penetration. Then the samples are washed under running water, immersed in a photographic developing solution and exposed to fluorescent light for 12 hours and thoroughly rinsed with distilled water.

The results obtained in this study showed that all the five tooth coloured restorative materials that were tested exhibited more microleakage on the gingival margins than on the occlusal margins. However, none of the material was able to completely eliminate microleakage at the enamel, dentin, or cementum margin. This finding is in agreement with other studies which concluded that cavity preparations with enamel margin result in consistently stronger bonds. Unique challenges are encountered with dentin surface bonding due to enamel that is 92% inorganic hydroxyapatite and dentin that is 45% inorganic by volume.

In this study, there was no statistically significant difference in the microleakage of groups V (Ionoseal) and IV (Cention N) at both occlusal and gingival margins. This finding is in accordance with previous studies.48 However, few studies have shown that there is statistically significant difference in microleakage of these materials.23 This could be due to difference in experimental designs and testing methods used in these studies.

In the present study maximum microleakage was observed in Conventional

GIC restoration (GROUP I) being attributed to the inherent nature of the material itself. The cohesive strength of glass ionomer cement is found to be lower than adhesive strength. The porous nature of the material may be an important factor that enhances potential for microleakage.7According to the study by Abd El Halim and

Discussion

Zaki D.,Glass ionomer cements are adhesive bioactive restorative materials with therapeutic action that were developed during the late 1970s.15 The anticariogenic property resulting from fluoride release turned out to be the most attractive aspect of this dental material.54 However, conventional GICs have been noted by several negative characteristics, such as prolonged setting time that restricts finishing and polishing for approximately 24 hours, sensitivity to moisture during initial hardening, strength, dehydration, rough surface texture, opaqueness, low fracture toughness, and poor wear resistance.16 An experimental in-vitro study by Hallett &

Garcie-Godoy explained that microleakage of GIC in the gingival margin exhibited greater leakage than the occlusal margin. This finding is in accordance with previously reported in vitro studies of microleakage of GIC restorations (Alperstein et al., 1983; Gordon et al., 1986; Thornton et al., 1988;Tsunekawa et al., 1992).11

The microleakage score of Zirconomer indicated that it has more microleakage score than Giomer. These findings were according to the results obtained in a study by Patel et al.,55 who evaluated almost similar outcomes when they tested the dye penetration of Zirconomer in human molar teeth. This could be explained due to the fact that the chemical structure of Zirconomer which comprises ceramic particles (zirconia) as fillers. It is possible that the zirconia fillers would cause interference in the chelating reaction between the calcium ions (Ca2+) of hydroxyapatite and carboxylic group (−COOH) of polyacrylic acid, another possible explanation may be the bigger size of the filler particle in Zirconomer prevents proper adaptation of this material to the tooth structure.

The giomer showed maximum microleakage scores, which was relates with the study by Deliperi et al56and Yadav et al57A study by Karim et al58 said that the

Discussion reason for maximum microleakage may be the high filler content, without bonding of the resin with S‑PRG filler (surface pre‑reacted glass). Reduced marginal adaptation of giomer in the present in vitro study may also be due to polymerization shrinkage resembling its typical resin composite like nature. Some authors suggest that the hygroscopic expansion which is an intrinsic property of this restorative material is the main cause of marginal deterioration of giomer restorations.59 In‑vivo studies conducted by U. M. Abdel‑Karim et al60also shown marginal deterioration of giomer restorations over a period of 3 years of clinical evaluation.47

Cention N is self-curing tooth coloured restorative material. Cention N is a full volume replacement material, designed to be applied conveniently in bulk and quickly. In this context, it is important that the material exhibit low polymerization shrinkage and low shrinkage force. Cention N contains a special patented filler

(partially functionalized by silanes) which keeps shrinkage stress to a minimum.

This Isofiller, which is also used in Tetric N-Ceram Bulk Fill, acts as a shrinkage stress reliever which minimizes shrinkage force, whereas the organic/inorganic ratio as well as the monomer composition of the material, is responsible for the low volumetric shrinkage. Fillers are responsible for imparting restorative materials with the adequate strength to withstand the stresses and strains of the oral cavity and to achieve acceptable clinical longevity. Cention N Powder contains the filler composition of Cention N . The fillers of Cention N were chosen to achieve strength but also to obtain the desired handling characteristics of the mixed material. All the fillers therefore (except ytterbium trifluoride) are surface-modified to ensure wettability by the liquid and incorporation into the polymer matrix.48 Due to its low

Discussion elastic modulus (10 GPa) the shrinkage stress reliever within Cention N reduces polymerization shrinkage and microleakage.43

IONOSEAL (resin reinforced light cure glass ionomer) is a new technical development that combines the benefits of a resin‑modified light‑cure glass ionomer and bonded nanofiller technology. The composition of ionoseal includes

Fluoroalminumsilicate, Bis-GMA, HEMA, TEDMA, champherechinon, amine.

Ionoseal showed less leakage than all other tested material at gingival margins. This may be due to the higher filler loading in the nano‑filled type that may result in lower polymerization shrinkage and lower coefficient of thermal expansion, thus improving the long‑term bonding to tooth structure. According to Effat khodadadi experimental study, The microleakage rate may be affected by the amount of resin content and filler particles. Ionoseal showed less microleakage when it is placed after etching and bonding agent application. Hence, it is essential for this material to be used in etching and bonding similar to resin based groups to reach clinically proper microleakage results. It is suggested that the other properties of this material such as microhardness, bond strength and so on can be investigated in future studies.

SUMMARY & CONCLUSION Summary and Conclusion

Marginal integrity of restorative materials provides better sealing ability for enamel and dentin and plays an important role in success of restoration in Class V cavities. Restorative material with good marginal adaptation improves the longevity of restorations.

This study was done to comparatively evaluate leakage pathway in occlusal and gingival margins of Class V cavities restored with five tooth coloured restorative materials, namely, Conventional Glass Ionomer cements, Zirconomer, Giomer,

Ionoseal, Cention N restored in class V cavities.

Class V cavities were prepared with occlusal margin in enamel, and the gingival margin in dentin and cementum of sound extracted premolars and randomly assigned into five experimental groups(n=8). Five different tooth coloured restorative materials were restored in respective groups.

Specimens were thermocycled, immersed in silver nitrate dye, sectioned longitudinally and analysed for leakage at the occlusal and gingival interfaces.

Depth of dye penetration along the lateral walls of each specimen was evaluated under stereomicroscope.

Based on the findings of this study, microleakage at Gingival margin was significantly more compared to the occlusal margin of the restoration of all the five groups. The microleakage score is highest for conventional GIC group and least for ionoseal group.

Summary and Conclusion

Within the limitations of this in-vitro study, we can conclude the following:

 None of the five materials were free from microleakage.

 All the five materials showed more microleakage at gingival margins

compared to occlusal margins.

 Among all the groups IONOSEAL a resin reinforced light cure glass

ionomer showed the least microleakage at the gingival and occlusal wall.

TABLES Tables

GROUP MEAN SD

CONVENTIONAL GIC 2.5 0.535

ZIRCONOMER 1.25 0.463

GIOMER 1 0.756

CENTION N 0.75 0.463

IONOSEAL 0.25 0.463

TABLE 1 OCCLUSAL MICROLEAKAGE

GROUP MEAN SD

CONVENTIONAL GIC 2 0.756

ZIRCONOMER 1.63 0.518

GIOMER 1.13 0.835

CENTION N 0.63 0.518

IONOSEAL 0.38 0.518

TABLE 2 GINGIVAL MICROLEAKAGE

Tables

GROUP GINGIVAL (n=8) OCCLUSAL (n=8)

CONVENTIONAL 3 2 1 2 3 2 1 2 2 3 2 3 3 2 2 3

GIC

ZIRCONOMER 2 1 2 2 1 1 2 2 1 1 2 1 1 2 1 1

GIOMER 0 2 1 0 2 1 1 2 2 0 1 1 0 2 1 1

CENTION N 1 0 1 0 1 1 1 0 1 0 1 1 1 1 0 1

IONOSEAL 1 0 0 0 1 0 1 0 0 0 1 0 0 1 0 0

TABLE 3 MICROLEAKAGE SCORES

Tables

GROUP N MEAN STD. STD. 95% CONFIDENCE MIN MAX INTERVAL FOR DEVIATION ERROR MEAN

LOWER UPPER BOUND BOUND

CONVENTIONAL 8 2.00 0.756 0.267 1.37 2.63 1 3 GIC

ZIRCONOMER 8 1.63 0.218 0.183 1.19 2.06 1 2

GIOMER 8 1.13 0.835 0.295 0.43 1.82 0 2

CENTION N 8 0.63 0.518 0.183 0.19 1.06 0 1

IONOSEAL 8 0.38 0.518 0.183 -0.06 0.81 0 1

TOTAL 40 1.15 0.864 0.137 0.87 1.43 0 3

SUM OF df MEAN SQUARE F SIGNIFICANCE SQUARES

BETWEEN 14.600 4 3.650 8.810 .000 GROUPS

WITHIN 14.8500 35 0.414 GROUPS

TOTAL 29.100 39

TABLE 4 (A) ONEWAY ANALYSIS OF GINGIVAL MICROLEAKAGE

Tables

Tukey HSD (I)Group (J)Group MEAN STD.ERROR SIG. 95% CONFIDENCE DIFFERENCE INTERVAL

(I-J) LOWER UPPER BOUND BOUND

CONVENTIONAL GIC ZIRCONOMER 0.375 0.322 0.771 -0.55 1.30

GIOMER 0.875 0.322 0.071 -0.05 1.80

CENTION N 1.375* 0.322 0.001 0.045 2.30

IONOSEAL 1.625* 0.322 0.000 0.70 2.55

ZIRCONOMER CONVENTIONAL GIC - 0.375 0.322 0.771 -1.30 0.55

GIOMER 0.500 0.322 0.536 -0.43 1.43

CENTION N 1.000* 0.322 0.029 0.07 1.93

IONOSEAL 1.250* 0.322 0.004 0.32 2.18

GIOMER CONVENTIONAL GIC - 0.875 0.322 0.071 -1.80 0.05

ZIRCONOMER -0.500 0.322 0.536 -1.43 0.43

CENTION N 0.500 0.322 0.539 -0.43 1.43

IONOSEAL 0.750 0.322 0.159 -0.18 1.68

CENTION N CONVENTIONAL GIC - 1.375* 0.322 0.001 -2.30 -0.45

ZIRCONOMER -1.000* 0.322 0.029 -1.93 -0.07

GIOMER -0.500 0.322 0.536 -1.43 0.43

IONOSEAL 0.250 0.322 0.936 -0.68 1.18

IONOSEAL CONVENTIONAL GIC - 1.625 0.322 0.000 -2.55 -0.70

ZIRCONOMER -0.500 0.322 0.004 -2.18 -0.32

GIOMER 0.500 0.322 0.159 -1.68 0.18

CENTION N 0.750 0.322 0.936 -1.18 0.68

*THE MEAN DIFFERENCE IS SIGNIFICANT AT THE 0.05 LEVEL Table 4(b) Post Hoc

vii

Tables

Kruskal-Wallis Test RANKS GROUP N MEAN RANK CONVENTIONAL GIC 8 30.75 ZIRCONOMER 8 27.25 GIOMER 8 20.50 CENTION N 8 13.63 IONOSEAL 8 10.38 TOTAL 40 Table 4 (c) NPar Tests

Test Statistics Gingival chi square 19.674 df 4 Asymp. sig .001 a. Kruskal wallis b. Grouping variable : GROUP

viii

Tables

GROUP N MEAN STD.DEVIATION STD.ERROR 95% CONFIDENCE MIN MAX INTERVAL FOR MEAN

LOWER UPPER BOUND BOUND

CONVENTIONAL 8 2.50 0.535 0.189 2.05 2.95 2 3 GIC

ZIRCONOMER 8 1.25 0.463 0.164 0.86 1.64 1 2

GIOMER 8 1.00 0.756 0.267 0.37 1.63 0 2

CENTION N 8 0.75 0.463 0.164 0.36 1.14 0 1

IONOSEAL 8 0.25 0.463 0.164 -0.14 0.64 0 1

TOTAL 40 1.15 0.921 0.146 0.86 1.44 0 3

SUM OF df MEAN SQUARE F SIGNIFICANCE SQUARES

BETWEEN 22.600 4 5.650 18.833 .000 GROUPS

WITHIN 10.500 35 0.300 GROUPS

TOTAL 33.100 39

TABLE 5 (A) ONEWAY ANALYSIS OF OCCLUSAL MICROLEAKAGE

Tables

Tukey HSD (I)Group (J)Group MEAN STD.ERROR SIG. 95% CONFIDENCE DIFFERENCE INTERVAL

(I-J) LOWER UPPER BOUND BOUND

CONVENTIONAL GIC ZIRCONOMER 1.250* 0.274 0.001 0.46 2.04

GIOMER 1.500* 0.274 0.000 0.71 2.29

CENTION N 1.750* 0.274 0.000 0.96 2.54

IONOSEAL 2.250* 0.274 0.000 1.46 3.04

ZIRCONOMER CONVENTIONAL GIC - 1.250* 0.274 0.001 -2.04 -0.46

GIOMER 0.250 0.274 0.890 -0.54 1.04

CENTION N 0.500 0.274 0.376 -0.29 1.29

IONOSEAL 1.000* 0.274 0.007 0.21 1.79

GIOMER CONVENTIONAL GIC - 1.500* 0.274 0.000 -2.29 -0.71

ZIRCONOMER -0.250 0.274 0.890 -1.04 0.54

CENTION N 0.250 0.274 0.890 -0.54 1.04

IONOSEAL 0.750 0.274 0.068 -0.04 1.54

CENTION N CONVENTIONAL GIC - 1.750* 0.274 0.000 -2.54 -0.96

ZIRCONOMER -0.500 0.274 0.376 -1.29 0.29

GIOMER -0.250 0.274 0.890 -1.04 0.54

IONOSEAL 0.500 0.274 0.376 -0.29 1.29

IONOSEAL CONVENTIONAL GIC - 2.250* 0.274 0.000 -3.04 -1.46

ZIRCONOMER -1.000* 0.274 0.007 -1.79 -0.21

GIOMER -0.750 0.274 0.068 -1.54 0.04

CENTION N -0.500 0.274 0.376 -1.29 0.29

*THE MEAN DIFFERENCE IS SIGNIFICANT AT THE 0.05 LEVEL Table 5(b) Post Hoc

Tables

Kruskal-Wallis Test RANKS GROUP N MEAN RANK CONVENTIONAL GIC 8 30.50 ZIRCONOMER 8 22.75 GIOMER 8 19.25 CENTION N 8 16.00 IONOSEAL 8 9.00 TOTAL 40 Table 5(c) NPar Tests

Test Statistics OCCLUSAL chi square 25.413 df 4 Asymp. sig .000 a. Kruskal wallis b. Grouping variable : GROUP

FIGURES Figures

FIGURE : 1 SELECTED SPECIMENS

xii

Figures

FIGURE : 2 CONVENTIONAL GLASS IONOMER

FIGURE : 3 ZIRCONOMER

xiii

Figures

FIGURE : 4 GIOMER

FIGURE : 5 CENTION N

FIGURE : 6 IONOSEAL

xiv

Figures

FIGURE : 7 SILVER NITRATE DYE

FIGURE : 8 SPECIMEN IMMERSED IN A DYE FOR DYE PENETRATION

Figures

FIGURE : 9 CROSS SECTION OF SPECIMEN FOR MICROLEAKAGE EVALUATION

FIGURE : 10 STEREOMICROSCOPE EXAMINATION OF SPECIMENS

xvi

Figures

FIGURE : 11 STEREOMICROSCOPIC PICTURE OF CONVENTIONAL GIC RESTORATION

FIGURE : 12 STEREOMICROSCOPIC PICTURE OF ZIRCONOMER RESTORATION

xvii

Figures

FIGURE : 13 STEREOMICROSCOPIC PICTURE OF GIOMER RESTORATION

FIGURE : 14 STEREOMICROSCOPIC PICTURE OF CENTION N RESTORATION

xviii

Figures

FIGURE : 15 STEREOMICROSCOPIC PICTURE OF IONOSEAL

RESTORATION

FIGURE : 16 MEAN COMPARISION OF OCCLUSAL MICROLEAKAGE SCORES

xix

Figures

FIGURE : 17 MEAN COMPARISION OF GINGIVAL MICROLEAKAGE SCORES

BIBILOGRAPHY Bibliography

1. K Trelles, J Arnabat, T España-Tost. Microleakage in Class V cavities with self-

etching adhesive system and conventional rotatory or laser Er,Cr:YSGG Laser

Ther. 2012 Dec 26; 21(4): 255–26.

2. Govil S, Gupta V, Bhatt A. A comparative evaluation of micro-leakage of

different tooth colored restorative materials. An in-vitro study. IJCPHR 2016;

1(1):10-14.

3. Najma Hajira NSW, Meena N.,GIOMER- The Intelligent Particle (New

Generation Glass Ionomer Cement). Int J Dent Oral Health.2015,2(4).

4. Indira Priyadarshini Bollu et al.,Comparative Evaluation of Microleakage

Between Nano-Ionomer, Giomer and Resin Modified Glass Ionomer Cement in

Class V Cavities- CLSM Study. Journal of Clinical and Diagnostic Research.

2016 May, Vol-10(5): ZC66-ZC70.

5. Lagisetti AK, Hegde P, Hegde MN. Evaluation of bioceramics and zirconia-

reinforced glass ionomer cement in repair of furcation perforations: An in vitro

study. J Conserv Dent 2018;21:184-9.

6. Soumita S, Utpal KD, Aditya M. Comparison of Microleakage In Class V Cavity

Restored with Flowable Composite Resin, Glass Ionomer Cement and Cention N.

IJIR 2017;3(8).

7. Mali P, Deshpande S, Singh A. Microleakage of restorative materials: An in vitro

study. J Indian Soc Pedod Prev Dent 2006;24:15-8.

8. AlHabdan AA. Review of microleakage evaluation tools. J Int Oral Health

2017;9:141‑5.

xxi

Bibliography

9. Hussein TA, Bakar WW, Ghani ZA, Mohamad D. The assessment of surface

roughness and microleakage of eroded tooth-colored dental restorative materials.

J Conserv Dent 2014;17:531-5.

10. Kaplan I, Mincer HH, Harris EF, Cloyd JS. Microleakage of composite resin and

glass ionomer cement restorations in retentive and nonretentive cervical cavity

preparations. The Journal of Prosthetic Dentistry. 1992 Oct;68(4):616–23.

11. Hallett KB, Garcia-Godoy F. Microleakage of resin-modified glass ionomer

cement restorations: An in vitro study. Dental Materials. 1993 Sep 1;9(5):306–11.

12. França FMG, Aguiar FHB, Santos AJS dos, Lovadino JR. Quantitative

evaluation of microleakage in class V cavities using one-bottle and self-etching

adhesive systems. Braz oral res. 2004 Sep;18(3):253–9.

13. Awliya WY, El-Sahn AM. Leakage Pathway of Class V Cavities Restored With

Different Flowable Resin Composite Restorations. Operative Dentistry. 2008 Jan

1;33(1):31–6.

14. Eden E, Topaloglu-Ak A, Cuijpers V, Frencken JE. Micro-CT for measuring

marginal leakage of Class II resin composite restorations in primary molars

prepared in vivo. Am J Dent 2008;21:393-7.

15. Abd El Halim S, Zaki D. Comparative evaluation of microleakage among three

different glass ionomer types. Oper Dent 2011;36:36-42.

16. Rekha C, Varma B, Jayanthi. Comparative evaluation of tensile bond strength

and microleakage of conventional glass ionomer cement, resin modified glass

ionomer cement and compomer: An in vitro study. Contemporary clinical

dentistry. 2012 Jul 1;3:282–7.

xxii

Bibliography

17. Gupta SK, Saraswathi V, Ballal V, Acharya S. Comparative evaluation of

microleakage in Class V cavities using various glass ionomer cements: An in

vitro study. Journal of Interdisciplinary Dentistry. 2012 Sep;2:164–9.

18. Poggio C, Chiesa M, Scribante A, Mekler J, Colombo M. Microleakage in Class

II composite restorations with margins below the CEJ: In vitro evaluation of

different restorative techniques. Med Oral. 2013;e793–8.

19. Donmez N et al. Microleakage of composite resin restorations in Class V

Cavities etched by Er-YAG laser with different pulse modes. J. LA&HA, Vol.

2013, No. 1; pp. 6-10.

20. Sooraparaju SG, Kanumuru PK, Nujella SK, Konda KR, Reddy KBK,

Penigalapati S. A Comparative Evaluation of Microleakage in Class V Composite

Restorations. International Journal of Dentistry. 2014;2014:1–4.

21.Diwanji A, Dhar V, Arora R, Madhusudan A, Rathore A. Comparative

evaluation of microleakage of three restorative glass ionomer cements: An in

vitro study. J Nat Sc Biol Med. 2014;5(2):373.

22. Giray FE, Peker S, Durmus B, Kargül B. of new glass ionomer restorative

materials in permanent teeth. EUROPEAN JOURNAL OF PAEDIATRIC

DENTISTRY. 2014;15:122.

23. Khodadadi E, Esmaeili B, Karimian N, Khafri S. Evaluation of microleakage of

Ionoseal filling material as a fissure sealant agent. CJDR. 2014;3(2).

24. Parolia A. A Comparative Evaluation of Microleakage around Class V Cavities

Restored with Different Tooth Colored Restorative Materials. 2014;13(1):7.

xxiii

Bibliography

25. Shruthi A, Nagaveni N, Poornima P, Selvamani M, Madhushankari G, Subba

Reddy V. Comparative evaluation of microleakage of conventional and

modifications of glass ionomer cement in primary teeth: An in vitro study. J

Indian Soc Pedod Prev Dent. 2015;33(4):279.

26. Rengo C, Goracci C, Ametrano G, Chieffi N, Spagnuolo G, Rengo S, et al.

Marginal Leakage of Class V Composite Restorations Assessed Using

Microcomputed Tomography and Scanning Electron Microscope. Operative

Dentistry. 2015 Jun;40(4):440–8.

27. Niranjan B, Shashikiran N, Singla S, Thakur R, Dubey A, Maran S. A

comparative microleakage evaluation of three different base materials in Class I

cavity in deciduous molars in sandwich technique using dye penetration and

dentin surface interface by scanning electron microscope. J Indian Soc Pedod

Prev Dent. 2016;34(4):324.

28. Sakri M, Koppal P, Patil B, Haralur S. Evaluation of microleakage in hybrid

composite restoration with different intermediate layers and curing cycles. J Dent

Allied Sci. 2016;5(1):14.

29. Motevaselian F, Tehran, Iran, et al. In Vitro Microleakage of Class V Composite

Restorations in Use of Three Adhesive Systems. J Islam Dent Assoc Iran. 2016

Jan 1;28(1):14–9.

30. Ozel E, Tuna EB, Firatli E. The effects of cavity-filling techniques on

microleakage in class II resin restorations prepared with Er:YAG laser and

diamond bur: A scanning electron microscopy study: Microleakage prepared with

Er:YAG laser and diamond bur: SEM study. Scanning. 2016 Sep;38(5):389–95.

xxiv

Bibliography

31. Somani R, Jaidka S, Arora S. Comparative evaluation of microleakage of newer

generation dentin bonding agents: An in vitro study. Indian J Dent Res.

2016;27(1):86.

32. Kr Rajisha. An in vitro evaluation of microleakage of a bulk fill composite resin

in class V cavities cured by two pulse modes. International Journal of Applied

Dental Sciences.2016; 2(4): 19-22.

33.Tavangar M, Zohri Z, Sheikhnezhad H, Shahbeig S. Comparison of

Microleakage of Class V Cavities restored with the Embrace WetBond Class V

Composite Resin and Conventional Opallis Composite Resin. The Journal of

Contemporary Dental Practice. 2017 Oct;18(10):867–73.

34.Kathal S, Bhayya DP, Gupta S, Rao A, Pal A, Saxena ST. Comparative

Evaluation of Microleakage of Zirconomer, Amalgomer CR, and Conventional

Glass Ionomer (Type II) as Restorative Cements in Primary Teeth: An in vitro

Study. Kumar A, editor. IJOCRWEB. 2017;5(3(Supplement)):376–82.

35. Samanta S, Das UK, Mitra A. Comparison of Microleakage In Class V Cavity

Restored with Flowable Composite Resin, Glass Ionomer Cement and Cention N.

2017;3(8):4.

36. Dennis D, Aswal D, Anastasia A. The effect of microleakage in class v cavity

using self-adhering flowable composite with the addition of acid etch. jemds.

2017 Feb 23;6(16):1276–80.

37. Synarellis A, Kouros P, Koulaouzidou E, Strakas D, Koliniotou-Koumpia E. In

Vitro Microleakage of class V Composite Restorations prepared by Er,Cr:YSGG

Laser and Carbide BUR. Balkan Journal of Dental Medicine. 2017 Mar

1;21(1):24–31.

xxv

Bibliography

38. Shathi IJ, Hossain M, Gafur MdA, Rana MdS, Alam MdS. A comparative study

of microleakage between giomer and ormocer restoration in class I cavity of first

permanent premolar teeth in vivo. Bangabandhu Sheikh Mujib Medical Univ J.

2017 Nov 25;10(4):214.

39. Khamverdi Z, Fazelian N, Aghaei M. Comparative Evaluation of Micro Leakage

in Class V Composite Resin Restorations Using Two Bulk Filled Resin-

Composites and One Conventional Composite (Grandio). International Journal of

Scientific Study. 2017;5(8):7.

40. Bansal D, Mahajan M. Comparative evaluation of different periods of enamel

microabrasion on the microleakage of class V resin-modified glass ionomer and

compomer restorations: An In vitro study. Indian J Dent Res. 2017;28(6):675.

41. Gupta M, Rao D, Hegde S. An in vitro evaluation of microleakage associated

with three different compomer placement techniques in primary molars. Contemp

Clin Dent. 2017;8(1):48.

42. Dr Paul George. “A Comparative Microleakage Analysis of a Newer Restorative

Material – An Exvivo Study”.” IOSR Journal of Dental and Medical Sciences

(IOSR-JDMS), vol. 17, no. 12, 2018, pg 56-60.

43. Hussin H, Bakar WW, Ghazali NM, Sajjad A. Microleakage assessment of a

new modified glass ionomer cement-nanozirconia-silica-hydroxyapatite

restorative material. J Int Oral Health. 2018;10(3):138.

xxvi

Bibliography

44. Nagy I, El-Sayed H, Shalaby M. Evaluation of marginal seal of different

composite restored class V cavity preparations with different cavosurface

margins. Tanta Dent J. 2018;15(3):140.

45. Patel M, Bhatt R, Makwani D, Dave L, Raj V. Comparative evaluation of

marginal seal integrity of three bulk-fill composite materials in Class II cavities:

An In vitro study. Adv Hum Biol. 2018;8(3):201.

46. Salman Km, Naik S, Kumar Nk, Merwade S, Brigit B, Jalan R. Comparative

evaluation of microleakage in Class V cavities restored with giomer, resin-

modified glass ionomer, zirconomer and nano-ionomer: An In vitro study. J Int

Clin Dent Res Organ. 2019;11(1):20.

47.Mazumdar P, Das A, Das U. Comparative evaluation of microleakage of three

different direct restorative materials (Silver Amalgam, Glass Ionomer Cement,

Cention N), in Class II restorations using stereomicroscope: An In vitro Study.

Indian J Dent Res. 2019;30(2):277.

48. International standard organization (ISO) TR 11405. Dental materials –

Guidance on testing of adhesion to tooth structure First ed. 1994;12-15.

49. Alani AH, Toh CG (1997) Detection of microleakage around dental restorations:

a review. Oper Dent 22: 173-185.

50. De Munck J, Van Landuyt K, Peumans M, Poitevin A, Lambrechts P, et al.

(2005) A critical review of the durability of adhesion to tooth tissue: methods and

results. J Dent Res 84: 118-132.

51. Mair LH (1991) Staining of in vivo subsurface degradation in dental composite

with silver nitrate Journal of Dental Research 70(3) 215-220.

xxvii

Bibliography

52. Li H, Burrow MF & Tyas MJ (2002) The effect of thermocycling regimens on

the nanoleakage of dentin bonding systems Dental Materials 18(3) 189-196.

53. Bona AD, Pinzetta C, Rosa V. Microleakage of acid etched glass ionomer

sandwich restorations. J Minim Interv Dent 2009 Jan;2(1):36-44.

54. Patel MU, Punia SK, Bhat S, Singh G, Bhargava R, Goyal P, et al. An in vitro

evaluation of microleakage of posterior teeth restored with amalgam, composite

and zirconomer – A stereomicroscopic study. J Clin Diagn Res 2015;9:ZC65‑7.

55. Deliperi S, Bardwell DN, Wegley C, Congiu MD. In vitro evaluation of giomers

microleakage after exposure to 33% hydrogen peroxide: Self‑etch vs. total‑etch

adhesives. Oper Dent 2006;31:227‑32.

56. Yadav G, Rehani U, Rana V. A comparative evaluation of marginal leakage of

different restorative materials in deciduous molars: An in vitro study. Int J Clin

Pediatr Dent 2012;5:101‑7.

57. Karim UM, Eraky ME, Etman WM. Threeyear clinical evaluation of two

nanohybrid giomer restorative composites. Tanta Med J 2014;11:21322.

58. Sunico MC, Shinkai K, Katoh Y. Two‑year clinical performance of occlusal and

cervical giomer restorations. Oper Dent 2005;30:282‑9.

59. Abdel‑Karim UM, El‑Eraky M, Etman WM. Three‑year clinical evaluation of

two nano‑hybrid giomer restorative composites. Tanta Dent J 2014;11:213‑22.

xxviii