Rajiv Gandhi University of Health Sciences s82

RAJIV GANDHI UNIVERSITY OF HEALTH SCIENCES

BANGALORE, KARNATAKA

ANNEXURE – II

PROFORMA FOR REGISTRATION OF SUBJECTS FOR

DISSERTATION

1 NAME OF THE CANDIDATE AND ADDRESS IN (BLOCK LETTERS)

2 NAME OF THE INSTITUTION

3 COURSE OF STUDY AND SUBJECT

4 DATE OF ADMISSION TO THE COURSE

5 TITLE OF THE TOPIC

6.1 NEED FOR THE STUDY:

The main objective of the study is to measure the color changes and flexural strength of heat polymerized acrylic resin after its immersion in denture cleansers, simulating a 180-day use. care instructions provided to patients during the denture placement appointment help in maintenance of a healthy oral mucosa. Beyond the concern for esthetics, the lack of adequate denture hygiene can cause biofilm accumulation and oral infections such as denture stomatitis of prosthesis by micro-organisms. methods, and their efficacy in removing stains and reducing biofilm formation on the surface irregularities of dentures have been reported.

The effervescent tablets are classified as chemical soak-type products, and when dissolved in water the sodium perborate readily decomposes to form an alkaline peroxide solution. This peroxide solution subsequently releases oxygen, thereby enabling a mechanical cleaning by the oxygen bubbles in addition to the chemical cleaning. are not used correctly. The whitening effect relates to the high temperature of the water used in the solution. Irregularities and porosities present on denture surfaces offer a favorable niche to retain stain and microbial plaque cleansers and disinfecting solutions may decrease the flexural strength of acrylic resins . Several studies have shown alterations in flexural strength when using hot water to prepare the cleansing solution

6.2 REVIEW OF LITERATURE

This study was conducted to measure the color change and flexural strength of heat-polymerized acrylic resin after its immersion in denture cleansers, simulating a 180-day use Thirty disk-shaped (15 mm x 4 mm) and 30 rectangular samples (65 mm x10 mm x3.3 mm) were prepared from heat-polymerized acrylic resin and immersed in Corega Tabs, Bony Plus, and distilled water. Color measurements (∆E) were determined by a colorimeter. The flexural strength (S) was measured using a 3-point bending test on universal testing machine. The ∆E and S values were submitted to statistical analysis by ANOVA, followed by a Student–Newman–Keuls test .The color changes were significantly higher for the Corega Tabs than for the control group. The mean DE values quantified by the National Bureau of Standards (NBS) were classified as Trace (0.0–0.5). The Bony Plus group had significantly higher surface roughness than the other groups. Corega Tabs and Bony Plus groups presented lower flexural strength than the control group. Although the color changes after the immersion in denture cleansers were clinically insignificant, the Corega Tabs group showed higher color differences. The Bony Plus group showed significantly increased surface roughness. Both effervescent tablets Corega Tabs and Bony Plus significantly diminished the flexural strength of the acrylic resin.

A study was conducted to assess flexural strength and color alteration of acrylic resins immersed in denture cleansers for different periods of time. Rectangular specimens (65x10x3mm) made from three heat-polymerized acrylic resins (Lucitone 550, QC-20 and Triplex) were assigned to three denture cleansers groups (Bony Plus, Corega Tabs and Efferdent Plus) and a control group (immersion in water). Soaking trials of 15 min and 8 h simulated 30 days of use. Flexural strength testing was carried out with 105 specimens on a universal testing machine. Color alterations were 1 visually assessed by examination of photographs taken from 21 specimens. Flexural strength means (in MPa) were analyzed statistically by analysis of variance and Tukey’s test at 5% significance level. There were significant differences (p<0.01) among the resins Lucitone (89.439 ± 7.962), Triplex (88.024 ± 5.167) and QC-20 (83.379 ± 7.153). No significant differences (p>0.05) were found either among the denture cleansers (Bony Plus = 87.693 ± 6.943; Corega Tabs = 86.955 ± 7.114; Efferdent Plus =86.195 ± 7.865 and control = 86.536 ± 7.012) or between the soaking periods (15 min = 86.875 ± 7.625 and 8 h = 87.432 ± 7.355) throughout the soaking cycles simulating 30 days of use. No color alterations were identified by visual examination. The findings of this study showed that chemical denture cleansers used according to the manufacturers’ specifications did not cause flexural strength alterations or color changes in heat-polymerized acrylic resins submitted to soaking cycles that simulated 30 days of use.

A study was conducted for hygienic maintenance of dentures is important to the continuing health of oral mucosa, A regular denture cleaning method is needed to remove microbial plate, preventing its reaccumulation while removing mucin, calculus, and stain,''Dentures may be cleaned both mechanically or chemically.'" Chemical cleansing agents are routinely used, although dentists and denture wearers have found that a whitening of the denture color occurs after varying periods of use,'' This phenomenon been correlated with the regular use of chemical 2 denture cleansers, and patients find this esthetically compromising. The most important disadvantages of using alkaline peroxides and alkaline hypochlorides as chemical cleansing agents are tarnish and corrosion of the metal denture components. Corrosion from such cleansers can substantially alter tbe form and durability of the metal components. It has been reported that clasp fracture, as well as wear of all framework parts, can result,''"'Acrylic resin whitening is an accompanying disadvantage of these solutions.

This study was conducted to evaluate color stability, surface roughness and flexural strength of acrylic resin specimens after immersion in alkaline peroxide and alkaline hypochlorite, simulating a period of one and a half year of use of overnight immersion. Sixty disc-shaped(16x4mm) and 80 rectangular specimens (65x10x3.3 mm) were prepared from heat-polymerized acrylic resin (Lucitone 550) and distributed into 4 groups (n=20): C1: without immersion, C2: 8 h immersion in distilled water; AP: 8 h immersion in alkaline peroxide effervescent tablet; SH: 8 h immersion in 0.5% NaOCl solution. Properties were evaluated at baseline and after the immersion. Color data were also calculated according the National Bureau of Standards (NBS). And were analyzed statistically by ANOVA and Tukey’s HSD test (α=0.05). AP (2.34 ± 0.41) caused color alteration significantly higher than C2 (0.39 ±0.30) and SH (1.73 ± 0.52). The mean ΔΕ values were classified as indicial for C2 (0.36± 0.29) and noticeable for AP (2.12 ± 0.39) and SH (1.59 ± 0.48). SH (0.0195 ± 0.0150) caused significantly higher ΔRa (p=0.000) than the C2 (0.0005 ± 0.0115) and PA (0.0005± 0.0157) groups. There was no statistically significant difference (p=0.063) among the solutions for flexural strength (C1: 105.43 ± 14.93, C2: 100.30 ± 12.43, PA: 97.61 ± 11.09,SH: 95.23 ± 10.18). Overnight immersion in denture cleansing solutions simulating a year and a half of use did not alter the flexural strength of acrylic resin but caused noticeable color alterations, higher for alkaline peroxide. The 0.5% NaOCl solution caused increase in surface roughness.

A study conducted for Color stability is an important property of denture base acrylic resin. Color changes indicate 3 the influence of denture cleansers on the color stability of acrylic resins. acrylic resin. direct reline acrylic resin (TokusoLite-Rebase) were evaluated. Five specimens of each material 10 x 10 x 2 mm, were immersed in 1 of 9 commercial denture cleanser solutions or distilled water (control). Color changes were measured with a colorimeter and evaluated using the CIE L*a*b* colorimetric system. Data were analyzed using 1-way and 3-way ANOVA and the Student- Newman- Keuls test (α=.05). denture base acrylic resins increased with time. The ΔE of the AP acrylic resin was larger than that of the other acrylic resins. The least discoloration was found with ZTC denture cleanser (acid type). The influence of alkaline peroxide-type denture cleanser (Steradent) on the color stability of HP acrylic resin and AP acrylic resin was significantly greater ( cleansers. These results suggest that the color stability of denture base acrylic resins is influenced by polymerization type and the type of denture cleanser used.

The study was conducted to quantify biofilm on the internal surface of upper complete dentures following six possible cleansing methods. Thirty-six edentulous subjects were submitted to a time- series trial and dentures were cleansed according to six methods: (i) rinsing with water; (ii) soaking in an alkaline peroxide solution (Bonyplus); (iii) brushing with dentifrice (Dentu-Creme) and soft Johnson and Johnson’s toothbrush; (iv) combination between soaking and brushing according to methods 2 and 3; (v) brushing with dentifrice (Dentu-Creme) and soft Oral B toothbrush; (vi) combination between soaking and brushing according to methods 2 and 5. Each method was randomly used throughout 21 days. Denture biofilm was disclosed by 1% neutral red solution and quantified by means of digital photos taken from the internalsurface. The six methods presented significant differences in percentage of biofilm coverage (repeated measures ANOVA, P < 0Æ0001). Method 1 showed the highest values, 2 was intermediate and other results were the lowest. The most efficacious approach was 6. Biofilm tended to accumulate predominantly over specific zones of the denture base, but this pattern did not change regardless of the method employed. It can be concluded that brushing alone was more effective than the chemical method employed. The best results were obtained by a combination of methods. 4

5 6 6.3 AIMS AND OBJECTIVES OF THE STUDY

This study is aimed to asses the effect of denture cleansers on physical properties of heat polymerised acrylic resin.

OBJECTIVES:

The objectives of this study are to evaluate the color change and flexural strength of heat polymerized acrylic resin after its immersion in denture cleansers.

MATERIALS AND METHODS:

7) 7.1 SOURCE OF DATA:

Two commercially available Denture cleansers to be used in this study are 1)Corega tabs( GSK Mfd by Stafford Miller-Ireland) 2)Fittydent ( Dr Reddy’s laboratory LTD. INDIA)

And one commercially available Heat polymerized acrylic resin to be used 1)Trevalon HI (Dentsply India Pvt.Ltd)

7.2 METHOD OF COLLECTION OF DATA(Including specimen fabrication, sampling, immersion procedure and analysis)

SPECIMEN FABRICATION:

x 10mm x3.3mm.

After the setting of stone, the flasks halves will be separated, the wax is removed and the stone mold is cleansed. Two coats of separating medium (DPI cold mould seal) will be applied to both dental stone surfaces. pressed into mold according to manufacturer’s instructions. The heat polymerization method is to be carried out. All flasks will be allowed to cool to room temperature before opening. After polymerization of the resin, the specimens are to be removed from the molds and immersed in distilled water for residual monomer elimination. The excess resin is trimmed with a tungsten carbide bur using a hand piece at low speed. One of the surfaces will be finished using 180,220,360 and 400 grit sandpaper and polished on wet rag wheel with slurry of pumice.

SAMPLING

IMMERSION PROCEDURE:

1- Corega tabs (10 disk and 10 rectangular ) 2- Fitty dent (10 disk and 10 rectangular) 3- Control Group( distilled water) (10 disk and 10 rectangular)

covered all specimen. The effervescent cleansers have to be prepared according to manufacturer’s directions, by adding one tablet to 200ml of warm tap water (40 specimens will be removed from the chemical solutions, thoroughly washed in running water, completely dried with absorbent paper, and then the procedure of immersion are to be repeated. be kept in distilled water, at room temperature (23+_ 2

Analysis : calibrated according to the manufacturer’s instructions using the supplied white calibration standard.

1mm/min. The flexural strength of each rectangular specimen will be later calculated.

DURATION OF THE STUDY:

STATISTICAL ANALYSIS:

7.3 Does the study require any investigation or interventions to be conducted on patients or human or animals? If so describe briefly

8 LIST OF REFERENCES:

1 Amanda Peracini MSc, Letı´cia Resende Davi MSc*, Natha´lia de Queiroz Ribeiro DDS, Raphael Freitas de Souza PhD, Cla´udia Helena Lovato da Silva PhD, Helena de Freitas Oliveira Paranhos PhD; Journal of Prosthodontic Research 54 (2010) 78–83

2 Sato S, Cavalcante MRS, Orsi IA, Paranhos HF, Zaniquelli O. Assessment of flexural strength and color alteration of heat-polymerized acrylic resins after simulated use of denture cleansers. Braz Dent J 2005;16:124–8.

3 U¨ nlu¨ A, Altay OT, Sahmali S. The role of denture cleansers on the whitening of acrylic resins. Int J Prosthodont 1996;9:266–70.

4 Helena de Freitas Oliveira Paranhos, Amanda Peracini, Marina Xavier Pisani, Viviane de Cássia Oliveira, Raphael Freitas de Souza, Cláudia Helena Silva- Lovato ; Brazilian Dental Journal (2013) 24(2): 152-156

5 Guang Hong, DDS, PhD,a Hiroshi Murata, DDS, PhD,b YingAi Li, DDS, PhD,c Sinshuke Sadamori, DDS, PhD,d and Taizo Hamada, DDS, PhDe J Prosthet Dent 2009;101:205-213

6 Paranhos H.F.O, Silva-lovato C. H, Souza R .F., Cruz P.C, Freitas. K. M & Peracini; A Journal of Oral Rehabilitation 2007 34; 606–612 9 SIGNATURE OF THE CANDIDATE

1 REMARKS OF THE GUIDE 0

1 NAME AND DESIGNATION OF DR.SHARNBASAPPA C.NAGARAL MDS 1 GUIDE (IN BLOCK LETTERS) PROFFESSOR AND HOD. DEPARTMENT OF PROSTHODONTICS INCLUDING CROWN AND BRIDGE. AL-BADAR RURAL DENTAL COLLEGE AND HOSPITAL. GULBARGA.

1 SIGNATURE 2

1 CO-GUIDE (IF ANY) 3 1 SIGNATURE 4

1 HEAD OF THE DEPARTMENT DR.SHARNBASAPPA C.NAGARAL MDS 5 PROFFESOR AND HOD. DEPARTMENT OF PROSTHODONTICS INCLUDING CROWN AND BRIDGE. AL-BADAR RURAL DENTAL COLLEGE & HOSPITAL, GULBARGA. KARNATAKA

1 SIGNATURE 6

1 REMARKS OF PRINCIPAL 7

1 SIGNATURE OF PRINCIPAL 8