DOCSLIB.ORG

Restoration of the Root Canal Treated Tooth

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Restoration of the Root Canal Treated Tooth Restoration of the root IN BRIEF • Provides a synopsis of the effects of root canal treatment on the strength of teeth. PRACTICE canal treated tooth • Summarises the available literature pertaining to the restoration of root filled teeth. S. Eliyas,*1 J. Jalili2 and N. Martin3 • Gives practitioners information on how to choose the appropriate temporary, interim and definitive restorations VERIFIABLE CPD PAPER required for anterior and posterior root filled teeth. When considering endodontically treated teeth, the quality of the restoration is important from the outset. It sheds light into possible causes of pulp necrosis or failure of endodontic treatment and influences the outcome of future endodontic treatment. A tooth undergoing endodontic treatment requires an effective coronal seal during and following completion of endodontic treatment. This paper discusses, using the available literature, the maintenance of optimal coronal seal and coronal integrity during and after root canal treatment. INTRODUCTION Table 1 The importance of a good coronal seal (GE = good endodontics, GR = good Root canal treatment involves the removal restoration) of necrotic and infected tissue followed by Study Measure of No. of teeth Outcome the provision of a well-condensed obtura- coronal seal tion to prevent further microbial prolifera- Ray & Trope90 Rads 1,010 (no post + cores) GR more important than GE tion within the canal system.1 The potential Tronstad et al.91 Rads 1,000 (post + cores GE more important than GR ingress of microbes into the canal system included) will compromise the outcome of endodontic Kirkevang et al.92 Rads 773 Better periapical status with GR treatment. The importance of an effective coronal seal in endodontics is well docu- Hommez et al.62 Exam & rads 745 Better periapical status with GR mented (Table 1). Boucher et al.63 Rads 5,373 No coronal restoration more periapical A root filled tooth is unlike a vital tooth areas due to the effect of endodontic treatment. It Segura-Egea et al.93 Rads 93 Better periapical status with GR is thought that endodontic treatment leads to ‘weakening’ of the remaining tooth struc- Tavares et al.94 Rads 1,035 Better periapical status with GR ture as a result of various factors: changes Ng et al.11 Exam & rads 1,452 Better periapical status with GR in tooth architecture, changes in the prop- erties of dentine and changes in proprio- ception. Although the effects are similar for susceptible to fracture. In anterior teeth, no Proprioception is also purportedly affected both anterior and posterior teeth, the con- difference in fracture susceptibility of root- by endodontic treatment with higher pain sequences are different due to the difference filled and non-root-filled anterior teeth has threshold seen in non-vital teeth and there- in tooth morphology and loading patterns. been shown.2 In posterior teeth endodontic fore increased loading of non-vital teeth. It The changes in tooth architecture are often procedures were shown to reduce the stiffness is thought that proprioception is reduced by attributed to the access cavity preparation of teeth by 5%, however, the presence of an 30% after endodontic treatment as a result and removal of the vital tissues, suppos- occlusal restoration reduced stiffness by 20% of pulpal nerves being involved in regulating edly rendering the tooth weaker and more and the presence of a mesio-occluso-distal masticatory load.8 The periodontal ligament restoration reduced tooth stiffness by 63%.3 It may act as a protective feature. The rele- 1Locum Consultant in Restorative Dentistry, Glenfield is the loss of the marginal ridges and occlusal vance of loading forces may be more prudent Hospital, University Hospitals of Leicester NHS Trust, 3,4 Groby Road, Leicester, LE3 9QP; 2Specialist Registrar in isthmus that leads to weakening of teeth. in parafunctional patients as parafunctional Restorative Dentistry, Charles Clifford Dental Hospital, Some have theorised that obtaining straight- loads can be six times the normal chewing Sheffield Teaching Hospitals NHS Foundation Trust, line access may weaken adjacent cusps;5 force (1.5 to 7 kg) for an excess of 35 min- Wellesley Road, Sheffield, S10 2SZ; 3Professor and Hon Consultant in Restorative Dentistry, Academic Unit others have suggested that post preparation utes in 24 hours, whereas normally teeth of Restorative Dentistry, School of Clinical Dentistry, removes radicular dentine, which weakens come together for chewing and empty swal- University of Sheffield teeth6 or that excess force during canal obtu- lows (eight minutes) for about 17.5 minutes *Correspondence to: Miss Shiyana Eliyas 7 Email: [email protected] ration causes tooth weakening. However, it every 24 hours. Chewing forces are predomi- must be remembered that most teeth requiring nantly vertical, but in parafunction they can Refereed Paper endodontic treatment have already suffered also be horizontal,9 though in anterior teeth Accepted 12 November 2014 DOI: 10.1038/sj.bdj.2015.27 caries, cracks, trauma and previous restora- there is a much greater horizontal vector ©British Dental Journal 2015; 218: 53-62 tions which may be the cause of weakness. of force depending on the guidance on the BRITISH DENTAL JOURNAL VOLUME 218 NO. 2 JAN 23 2015 53 © 2015 Macmillan Publishers Limited. All rights reserved PRACTICE anterior teeth. However, nothing is reported in the literature in relation to parafunction Table 2 The incidence of pulp death under crown and bridgework and failure of endodontically treated teeth. Study Number of teeth Method of Follow up Pulp death Pulp death The process of endodontic treatment pre- assessment (crowns) (bridges) dominantly results in collagen depletion; this Bergenholtz & Nyman95 417 crowns Notes & rads 4-13 years 3% 15% affects the elasticity of the dentine and pre- 255 bridge abutments disposes to fracture during shearing forces. A Karlsson96 944 bridge abutments Exam & rads 10 years - 10% number of steps in the protocol of root-canal treatment have a negative effect on collagen Jackson et al.97 202 crowns Exam & rads 2-6 years 5.7% including the use of sodium hypochlorite 235 bridge abutments (NaOCl), with concentrations over 2% hav- Valderhaug et al.98 46 crowns Rads 25 years 17% 10 ing more deleterious effects. There is a syn- 112 bridges ergistic effect of ethylenediaminetetraacetic Saunders & Saunders99 458 crowns Rads ? 19% - acid (EDTA) and NaOCl.10 The use of calcium hydroxide (Ca(OH) ) dressing can reduce the 2 Cheung et al.100 284 crowns Exam & rads 7-21 years 16% 33% flexural strength of dentine and microbial 102 bridges products themselves can degrade collagen.10 Heat created during treatment can further denature collagen and dehydrate the tooth Table 3 Detecting the quality of the coronal seal before and after dismantling restorations structure, although the loss of pulp or loss (Abbott 2004)22 of moisture per se has not been shown to Before restoration removal After restoration removal affect biomechanical properties of dentine.10 NaOCl, EDTA and Ca(OH)2 are essential for Caries 47 (19.2%) 211 (86.1%) the successful outcome of root-canal treat- ment11 yet affect the strength and restorative Cracks 57 (23.3%) 147 (60%) viability of the remaining dentine. Marginal breakdown 96 (39.2%) 244 (99.6%) It is noteworthy that although all root filled teeth are somewhat ‘weakened’ often as a result of injury before endodontic treat- crown has been present for any length of breakdown from clinical and radiographic ment, the anterior and posterior teeth are time, the loss of vitality or failure of endo- examinations (Table 3).22 This highlights the loaded differently in function and therefore dontic treatment may be as a result of leak- importance of coronal disassembly to deter- interim and definitive restorations on root age which is likely to go undetected if the mine the suitability for treatment and prog- filled teeth should provide favourable load coronal restoration is not dismantled. In few nosis before endodontic treatment, especially distribution as to prevent potential fracture exceptional situations, there may be a need with crowns and conventional cements. It is of the remaining tooth structure. The same to maintain the restoration and access the the authors’ experience that the true status type of restoration is not ideal for both canal system through the existing restora- of the cement interface can only be visual- anterior and posterior teeth. The restora- tion, such as the need for endodontic treat- ised once the restoration is sectioned and tive component of endodontic treatment ment following very recent provision of a removed, thus enabling an accurate assess- should optimise the tooth’s survival with a cuspal coverage restoration. ment to be made. good coronal seal, cuspal protection where The retention of the restoration will be Although maintaining the restoration required and prevention of further primary affected by the act of making an access cav- may be seen as advantageous for retaining disease. This article outlines the available ity within the restoration. In anterior teeth rubber dam clamps, the presence of crowns evidence for the restoration of root filled there may be up to a 60% decrease in the and large amalgam restorations can hinder treated teeth, both during and after endo- retention of crowns following endodontic visibility significantly. Where crowns are dontic treatment. access through the existing crown.18 Based present, there may also be loss of orienta- on the effect of
Load more

Recommended publications
  • Dental Amalgam: Public Health and California Dental Association 1201 K Street, Sacramento, CA 95814 the Environment 800.232.7645 Cda.Org July 2016
    Dental Amalgam: Public Health and California Dental Association 1201 K Street, Sacramento, CA 95814 the Environment 800.232.7645 cda.org July 2016 Issue Summary but no cause-and-effect relationship has been established between the mercury in dental amalgam and any systemic illnesses in either Dental amalgam is an alloy made by combining silver, copper, tin patients or dental health care workers. and zinc with mercury. Amalgam has been used to restore teeth Federal, state and local environmental agencies regulate for levels of affected by decay for more than a hundred years. More recently, “total mercury” because it does not degrade and can change from other materials, such as composite resins, have provided dentists one form to another, allowing it to migrate through the environment, and patients with an option other than amalgam, and because though there is insufficient scientific evidence that dental amalgam in composite restorations can match tooth color, they have become more the environment is a significant source of methylmercury. popular than the silver colored dental amalgam. However, because of its greater durability and adaptability than alternative materials, Nonetheless, it is prudent for dentistry to take steps to reduce the amalgam is still considered the best option for certain restorations, release of amalgam waste or any potentially harmful materials to the especially where the filling may be subjected to heavy wear, or where environment because dentistry’s role as a public health profession it is difficult to maintain a dry field during placement. Also, because naturally includes environmental stewardship. Organized dentistry amalgam material is less costly than composite material, it often encourages and supports constructive dialogue with individuals and represents a more economical choice for patients.
    [Show full text]
  • Mercury Release from Dental Amalgams Into Continuously Replenished Liquids
    dental materials Dental Materials 19 (2003) 38±45 www.elsevier.com/locate/dental Mercury release from dental amalgams into continuously replenished liquids T. Okabea,*, B. Elvebaka, L. Carrascoa, J.L. Ferracaneb, R.G. Keaninic, H. Nakajimad aDepartment of Biomaterials Science, Baylor College of Dentistry, Texas A&M University Health Science Center, 3302Gaston Avenue, Dallas, TX 75246,USA bDepartment of Biomaterials and Biomechanics, Oregon Health Sciences University, Portland, OR, USA cDepartment of Mechanical Engineering and Engineering Science, University of North Carolina at Charlotte, Charlotte, NC, USA dDepartment of Dental Materials Science, Meikai University School of Dentistry, Sakado, Japan Received 20 June 2000; revised 15 October 2001; accepted 11 December 2001 Abstract Objective: Studies have been performed using high- and low-copper amalgams to measure the amounts of mercury dissolution from dental amalgam in liquids such as arti®cial saliva; however, in most cases, mercury dissolution has been measured under static conditions and as such, may be self-limiting. This study measured the mercury release from low- and high-copper amalgams into ¯owing aqueous solutions to determine whether the total amounts of dissolution vary under these conditions when tested at neutral and acidic pH. Methods: High- and low-copper amalgam specimens were prepared and kept for 3 days. They were then longitudinally suspended in dissolution cells with an outlet at the bottom. Deionized water or acidic solution (pH1) was pumped through the cell. Test solutions were collected at several time periods up to 6 days or 1 month and then analyzed with a cold vapor atomic absorption spectrophotometer. After dissolution testing, the specimens were examined using SEM/XEDA for any selective degradation of the phases in the amalgam.
    [Show full text]
  • DEPARTMENT of HEALTH and HUMAN SERVICES Food and Drug Administration 21 CFR Part 872 [Docket No. FDA-2008-N-0163] (Formerly Dock
    DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration 21 CFR Part 872 [Docket No. FDA-2008-N-0163] (formerly Docket No. 2001N-0067) RIN 0910-AG21 Dental Devices: Classification of Dental Amalgam, Reclassification of Dental Mercury, Designation of Special Controls for Dental Amalgam, Mercury, and Amalgam Alloy AGENCY: Food and Drug Administration, HHS. ACTION: Final rule. SUMMARY: The Food and Drug Administration (FDA) is issuing a final rule classifying dental amalgam into class II, reclassifying dental mercury from class I to class II, and designating a special control to support the class II classifications of these two devices, as well as the current class II classification of amalgam alloy. The three devices are now classified in a single regulation. The special control for the devices is a guidance document entitled, “Class II Special Controls Guidance Document: Dental Amalgam, Mercury, and Amalgam Alloy.” This action is being taken to establish sufficient regulatory controls to provide reasonable assurance of the safety and effectiveness of these devices. Elsewhere in this issue of the FEDERAL REGISTER, FDA is announcing the availability of the guidance document that will serve as the special control for the devices. DATES: This rule is effective [insert date 90 days after date of publication in the FEDERAL REGISTER]. 2 FOR FURTHER INFORMATION CONTACT: Michael E. Adjodha, Food and Drug Administration, Center for Devices and Radiological Health, 10903 New Hampshire Ave., Bldg. 66, rm. 2606, Silver Spring, MD 20993-0002, 301-796-6276. SUPPLEMENTARY INFORMATION: I. Background A. Overview 1. Review of Scientific Evidence a. Evidence Related to the Population Age Six and Older i.
    [Show full text]
  • Dental Restorative Materials: the Choices Fillings
    Dental Restorative Materials: The Choices fillings. No scientific studies have shown any link between amalgam fillings and any health effects. Organizations including the National Dental Restorations Institutes of Health, US Public Health Service, Center for Disease Control There are two types of dental restorations: direct and indirect. and Prevention and the US Food and Drug Administration have all supported this conclusion. Nonetheless, where there is allergy to mercury Direct restorations are fillings placed into a prepared cavity in a single visit. and in instances where there may be sensitivity to mercury such as in They are usually soft and are hardened by a chemical reaction or a bright light. children from conception to the age of six, parents may want to discuss Most often these fillings are made of metal or resin. filling material options with their dentists. Indirect restorations (i.e.: inlays, onlays, veneers, crowns and bridges) are large, more involved, often require two or more visits to complete, are cemented or Available Filling Material Options bonded into place, and are usually made of metal, resin or ceramic materials. Amalgam and “composites” are the most common dental material options. The chart on the reverse side of this brochure provides information on all of Composites are mixtures of plastic resins that are normally white or “tooth- these restoration techniques. The following discussion focuses on the more colored”. In recent years there has been a marked increase in the development of common direct restoration techniques. composites. More information on the characteristics and risks and benefits of these materials is presented in the chart on the reverse of this page.
    [Show full text]
  • Dental Amalgam Facts
    DENTAL AMALGAM FACTS What is dental amagam? Most people recognize dental amalgam as silver fillings. Dental amalgam is a mixture of mercury, an alloy of silver, tin and copper. Mercury makes up about 45-50 percent of the compound. Mercury is used to bind the metals together and to provide a strong, hard durable filling. After years of research, mercury had been found to be the only element that will bind these metals together in such a way that can be easily manipulated into a tooth cavity. The small squeaking sound that you hear when a amalgam filling is being placed is the squeezing of the mixture, which expresses the excess mercury from the filling. This excess mercury discarded and only small amounts are left bound to the other metals. Is the mercury in dental amalgam safe? The safety of dental amalgams has been reviewed extensively over the past ten years. When mercury is combined with other materials in dental amalgam, its chemical nature changes, so it is essentially harmless. The amount released in the mouth, under the pressure of chewing and grinding is extremely small and no cause for alarm. In fact, it is less than what patients are exposed to in food, air and water. Ongoing scientific studies conducted over the past 100 years continue to prove that amalgam is not harmful. Why do dentists use dental amalgams? Dentists use dental amalgams because they achieve greater longevity and are less costly to place. Dental amalgam have withstood the test of time, which is why it is the material of choice.
    [Show full text]
  • Retrieval of Amalgam from the Root Canal Space Iris Slutzky-Goldberg, DMD1/Joshua Moshonov, DMD2
    Slutzky-Goldberg.qxd 3/27/06 4:23 PM Page 318 QUINTESSENCE INTERNATIONAL Retrieval of amalgam from the root canal space Iris Slutzky-Goldberg, DMD1/Joshua Moshonov, DMD2 Removal of foreign objects from the root canal can be very frustrating. The use of a variety of instruments and techniques has been suggested for the retrieval of obstacles from root canals during endodontic treatment. This article describes a method for retrieving a large mass of amalgam restoration that was wedged into the root canal. The amalgam, which had served as the provisional restorative material during apexification of an immature ante- rior tooth, was inadvertently pushed into the root canal. After the mass was bypassed, the amalgam was loosened with the aid of copious irrigation, chelation, and flotation. Hedstrom files twisted around the object allowed sufficient grip for its retrieval, enabling completion of the root canal treatment. (Quintessence Int 2006;37:318–321) Key words: amalgam, bypass, chelation, foreign object, retrieval, root canal Removal of foreign objects from the root obstructing object cannot be grasped, since canal is a complicated procedure. Fractured by so doing there is a possibility to loosen posts, silver points, and separated instru- and retrieve the object.3 ments are the main obstructions found, and Reamers and files should be used to these must either be removed from the root bypass the object, and solvents can be canal without changing the canal’s morphol- applied to loosen its cementation.4 Alterna- ogy or be bypassed.1 Careful instrumenta- tively, after the object is bypassed, two or tion, irrigation, and flotation are used to three Hedstrom files can be used alongside remove these obstructions.2 the bypassed instrument and twisted around According to the literature, a variety of it, so as to provide a sufficient grip for its instruments and techniques facilitate the retrieval.3,5 removal or bypass of an obstructing object in Use of ultrasonic devices may be helpful the root canal.
    [Show full text]
  • Corrosion of Amalgams in Oral Cavity
    Number2 Volume 17 April 2011 Journal of Engineering CORROSION OF AMALGAMS IN ORAL CAVITY Ghassan L.Yusif Mechanical department University of Baghdad ABSTRACT This paper is a study of the effect of natural saliva (oral cavity) and a fluoride mouthwash on dental amalgams .Two types electrodes were made the first was of a high copper amalgam while the second was made from a low copper amalgam. They were immersed in two types of electrolytes for twelve hours and the whole galvanic cell was connected to a computer via a potentiosat. Their corrosion currents, corrosion voltage and corrosion resistance was recorded and compared to find which medium that is usually has the most severe effect on the amalgams corrosion. اﻟﺨﻼﺻﺔ ﺗﻢ ﻓﻲ هﺬا اﻟﺒﺤﺚ دراﺳﺔ ﺗﺄﺛﻴﺮ ﻣﺤﻠﻮل اﻟﻔﻠﻮراﻳﺪ واﻟﻠﻌﺎب اﻟﻄﺒﻴﻌﻲ ﻋﻠﻰ ﺳﺒﻴﻜﺔ ﺣﺸﻮﻩ اﻟﺴﻦ اﻟﺰﺋﺒﻘﻴﺔ ﺣﻴﺚ ﺗﻢ ﺻﻨﺎﻋﺔ ﻧﻮﻋﻴﻦ ﻣﻦ اﻟﺤﺸﻮات اﻟﺰﺋﺒﻘﻴﺔ اﻷوﻟﻰ ﻋﺎﻟﻲ اﻟﻨﺤﺎس واﻟﺜﺎﻧﻲ واﻃﺊ اﻟﻨﺤﺎس . ﺗﻢ ﻏﺮﺳﻬﻤﺎ ﻓﻲ ﻣﺤﻠﻮﻟﻴﻦ اﻟﻤﺬآﻮرﻳﻦ ﻗﺎﺑﻠﻴﻦ ﻟﻠﺘﻮﺻﻴﻞ اﻟﻜﻬﺮﺑﺎﺋﻲ ﻟﻔﺘﺮة اﺛﻨﺎ ﻋﺸﺮ ﺳﺎﻋﺔ وﺗﻢ إﻳﺠﺎد ﻣﻘﺎوﻣﺘﻬﻤﺎ ﻟﻠﺘﺂآﻞ واﻟﺘﻴﺎر اﻟﻤﻘﺎوم ﻟﻠﺘﺂآﻞ وﻓﻮﻟﺘﻴﺔ اﻟﺘﺂآﻞ ﻣﻊ اﻟﻤﻘﺎرﻧﺔ ﺑﻴﻨﻬﻤﺎ وإﻳﺠﺎد إي اﻟﻤﺤﻠﻮﻟﻴﻦ ﻟﻪ اﻟﺘﺄﺛﻴﺮ اﻻﺳﻮء ﻓﻲ ﻋﻤﻠﻴﺔ اﻟﺘﺂآﻞ ﻟﻠﺤﺸﻮ ﺗﻴ ﻦ اﻟﺰﺋﺒﻘﻴﺘﻴﻦ. KEYWORDS: amalgam, dental materials, corrosion of teeth fillings, saliva effect on amalgams 366 Ghassan L.Yusif Corrosion of Amalgams In Oral Cavity INTRODUCTION: is that it can react with water and produce zinc oxide (ZnO2) and hydrogen gas, if it is produced Amalgams are found in posterior sites in the inside the amalgam and contribute to tooth failure. mouth. Dental amalgams are alloys that contain The beneficial effect is that the zinc makes the Mercury (Hg), Tin (Sn) and Silver (Ag) as the amalgams mixture more plastic and easy to handle main alloy ingredients.
    [Show full text]
  • Dental Amalgam Dr.Hasan AL- Rammahi Lec
    2nd class Dental Amalgam Dr.Hasan AL- Rammahi Lec. 6 Dental amalgam is a powder of silver-tin alloy mixed with mercury. Composition of the Conventional amalgam (Traditional). Silver (Ag) 65%: Advantages: increasing strength, promoting setting when mixed with mercury(increasing the setting time ,reducing the flow and resisting the tarnish and corrosion . Disadvantage: high degree of setting expansion. b- Tin (Sn) 25-29%: Advantages aids in amalgamation process because it has great affinity to mercury and decrease expansion within practical limit. Disadvantage: Large amount of tin cause decrease strength, prolong the setting time ,decrease corrosion resistance and increase flow of amalgam. c- Copper (Cu) 6%: increase strength and hardness and setting expansion but decrease flow d- Zinc (Zn) 0-2 %: Its presence is not essential, advantage: It prevents oxidation during alloy ingot manufacture. Disadvantage: It gives rise to delayed or secondary expansion if zinc containing alloys are contaminated with moisture. e-Palladium: 0-1 %: It improves the corrosion resistance and the mechanical properties. f- Indium: 0-4 %: In high copper alloy it enhances the clinical performance of amalgam restoration as it reduces the evaporation of mercury and the amount of mercury required to wet the alloy particles . Property Ingredient Sliver Tim Copper Zinc Strength Increases Decreases Increases Expansion Increases Decreases Increases Flow Decreases Increases Decreases Setting time Decreases Increases Decreases Corrosion Decreases Increases Decreases Workability Increases Increases Classifications of the types of the amalgam according to : I-Shape of the particles: 1-Lath-cut particles alloys( fig a) 2-S.u,herical particles alloys (fig b) 3- admixed particles alloys (Disperse alloy): mixture of lathe-cut with spherical alloy(fig-c) II-Zinc present 1- Zinc- containing alloys ---------------Alloy which contain more than 0.01 % 2- Zinc free; non zinc alloys).
    [Show full text]
  • The Dental Amalgam Controversy: a Review George Feuer, Phd, Cmsc, FRIC* H Stephen Injeyan, Msc, Phd, DC*
    0008-3194/96/169-178/$2.000/©JCCA 1996 The dental amalgam controversy: a review George Feuer, PhD, CMSc, FRIC* H Stephen Injeyan, MSc, PhD, DC* In spite ofthe long history ofmercury amalgam as a En depit de 1'historique e'tendu de l'amalgame au dental restorative material, its use continues to be mercure a titre de materiel de restauration dentaire, son controversial. utilisation demeure controverse'e. L'amalgame dentaire Mercury vapour is continuously releasedfrom dental rejette continuellement des vapeurs de mercure qui, en amalgam and is ultimately absorbed into a variety of bout de ligne, sont absorbe'es par une varie'te de tissus. tissues. Experimental data have demonstrated that the Les donne'es expe'rimentales ont de'montre' que uptake, tissue retention and excretion ofmercuryfrom 1'absorption, la retention par les tissus et I'excrition du dental amalgam is significant. Evidence has mercure a partir des amalgames dentaires etaient accumulated indicating a relationship between tissue significatives. Des preuves ont ete' accumule'es indiquant mercury levels and a multitude ofclinical une relation entre le niveau de mercure des tissus et une manifestations. However, the clinical significance of multitude de manifestations cliniques. Cependant, la mercury toxicityfrom dental amalgams is a matterfor signification clinique de la toxicite du mercure a' partir debate. The literature is devoid ofrandomized clinical des amalgames dentaires reste un sujet de debat. La trials that are rigorously designed to address this issue. documentation a' ce sujet est de'pourvue de'tudes Thus, although research data renders the notion of cliniques re'parties au hasard qui sont rigoureusement amalgam safety questionable, the dental community conCues pour evaluer ce probleme.
    [Show full text]
  • Longevity of Amalgam Build-Up Restorations in Endodontically Treated Teeth
    Original Article Longevity of Amalgam Build-Up Restorations in Endodontically Treated Teeth H. Kermanshah 1, S. Ghabraei 2, MJ. Kharrazifard 3, M. Monjazeb 4 , N. Farahmandpour 5 . 1 Associate Professor, Dental Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran; Department of Operative Dentistry, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran 2 Assistant Professor, Department of Endodontics, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran 3 Research Member, Dental Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran 4 Dentist, Private Practice, Sydney, Australia 5 Restorative Dentistry Specialist, Hjørring, Denmark Abstract Background and Aim: Restoration of endodontically treated teeth is one of the most important and challenging topics in restorative dentistry. Longevity of such restorations is an essential factor in treatment planning. Amalgam build-up is a conservative method for restoration of endodontically treated teeth. Therefore, this study aimed to assess the longevity of this type of restoration in endodontically treated molar teeth. Materials and Methods: In this retrospective study, 110 endodontically treated molar teeth of 98 patients that had received amalgam build-up restorations with at least one cusp coverage with 3-10 years of longevity were evaluated. The restorations included mesio-occluso-distal (MOD;40%), disto-occlusal (DO;23%), mesio-occlusal (MO;17%) and complex amalgam restorations (20%). Binary logistic regression and Kaplan-Meier tests were used for statistical analysis. Results: Of all restorations, cracks were observed in 22.7% of restorative materials and 10.9% of teeth. Secondary caries was found in 29% of the teeth.
    [Show full text]
  • Amalgam Alloy Constituents Effects
    --Amalgam Alloy Constituents Effects Amalgam alloy consists of different elements depending on the type of amalgam, but almost the three basic elements (Ag, Sn, Cu) exist, and sometimes Zn, Pd, and In. 1. Silver Silver reacts with mercury forming (Ag2Hg3) (γ1) phase which is the matrix of the dental amalgam structure and has a strong influence on both the mechanical behavior of the amalgam and its interaction with the environment. Silver increases strength and expansion, and has good corrosion resistance. 2. Tin In low copper amalgam tin reacts with mercury forming a network of (Sn7Hg) phase (γ2), the γ2 phase in the structure of the set amalgam was the principal phase undergoing corrosive breakdown. Because the γ2 phase formed a coherent network in the amalgam, the corrosion continued throughout the amalgam structure with time. γ2 phase have been eliminated by increasing the copper content, where tin reacts with copper forming η phase (Cu6Sn5) which has better properties than γ2 phase. Tin decreases strength and expansion and lengthens the setting time. 3. Copper Copper increases strength, reduces tarnish and corrosion, and reduces creep and, therefore, marginal deterioration. Copper accomplishes these effects by tying up tin, preventing the formation of gamma 2(γ2), the weakest, most tarnish- and corrosion-prone phase, and the phase with the highest creep values. In addition, it reduces creep by tying up tin and forming copper-tin (Cu6Sn5), the eta phase( η), whose crystals interlock to prevent slippage and dislocations at the grain boundaries of gamma-1( γ1) particles which is a major cause of creep in amalgam.
    [Show full text]
  • The Choices You Have Mercury Amalgam and Other Filling Materials
    Composite (resin) Advantages: Composite is a mixture of plastic resin. These Gold is extremely strong. Fillings made of gold fillings are also called plastic or “white fillings.” alloy will last a long time. This type of material may be either self-hardening www.ct.gov/deep/mercury or may be hardened by exposure to blue light. Gold alloy may have porcelain fused to the 79 Elm Street outside surface to make it tooth colored. Hartford, CT 06106-5127 Composite is used for fillings, inlays and veneers. Sometimes it is used for replacing parts of broken No toxic or environmental effects have been teeth. identified to date. Fillings: Advantages: Disadvantages: The Choices You Have These fillings are the color of natural teeth. Gold has a high cost, more than all other Composite may be used on either front or back materials. teeth. More than one dental appointment is needed to Fillings are usually done in one visit. complete these fillings. Composite is a relatively strong material. Fillings are gold colored if not covered with Disadvantages: Porcelain This type of filling can break and wear out more Porcelain is a mix of glass-like materials. easily than metal fillings, especially in areas of Sometimes it is called ceramic. It is used for tooth heavy biting forces. As a result, composite colored crowns, bridges, inlays and onlays. Fillings fillings may need to be replaced more often than made of porcelain are made in a dental lab and sent metal fillings. back to the dentist to cement into place. Compared to other fillings, composite fillings are Advantages: sometimes difficult and time-consuming to place.
    [Show full text]