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Recent advances in the field of endodontics have greatly improved the outcome and success rate of dental materials. For last three decades, there has been great interest in the development of bioactive dental material with the ability to interact and induce surrounding dental tissues to promote regeneration of pulpal and periradicular tissues. As these bioactive materials are mainly based on calcium silicates, they are also referred to as Calcium Silicate materials. The first material introduced was Mineral Tri-oxide Aggregate, which, due to its favourable biological properties, gained importance initially. However, later, due to its drawbacks, liked is colouration, long setting time and difficult manipulation, several modifications were done and newer bioactive materials, such as Biodentine, BioAggregate, Endosequence, Calcium-Enriched Mixture etc., were developed. The main applications of these materials are for pulp capping (direc t/indirec t), pulpotomy, perforation repair, resorption defects, apexogenesis and as retrograde filling materials, apexification and endodontic sealers. This review discusses the various types of bioactive materials, their composition, setting mechanism, and literature evidence for current applications.

Introduction: The purpose of this study was to evaluate the two-body wear resistances of natural enamel and four dental materials in vitro., Methods: The testing machine was modified to form a type of pin-on-disk wear test apparatus. Four dental material specimens (Au-Pd alloy, Ag-Pd alloy, FiltekTMP60 and FiltekTMZ350 composite resins) and enamel were used as the pins, and a steatite ceramic grinding wheel was used as the abrasive counter face. The wear volume loss and the rigidity value was measured. The worn surface and the element analysis of the debris were analyzed., Result: The wear volume loss of Au-Pd alloy and its steatite antagonists were the nearest to those of the dental enamel. SEM microphotographs showed that, the main wear mechanism of the dental materials was abrasive and adhesive wear., Conclusions: Au-Pd alloy had good wear resistance and was more suitable for dental applications than other three dental materials., (Copyright © 2017 National Medical Association. Published by Elsevier Inc. All rights reserved.)

Objectives:   Composites can be classified differently, according to manufacturer information, filler particle size, resin-monomer base, or viscosity, for example. Using clinical trial data, network meta-analyses aim to rank different composite material classes. Dentists then use these ranks to decide whether to use specific materials. Alternatively, annual failure rates (AFRs) of materials can be assessed, not requiring any classification for synthesis. It is unclear whether different classification systems lead to different rankings of the same material (ie, erroneous conclusions). We aimed to evaluate the agreement of material rankings between different classification systems., Methods:   A systematic review was performed via MEDLINE, Cochrane Central Register of Controlled Trials, and EMBASE. Randomized controlled trials published from 2005-2015 that investigated composite restorations placed in load-bearing cavitated lesions in permanent teeth were included. Network meta-analyses were performed to rank combinations of composite classes (according to manufacturer, filler particle size, resin-monomers, viscosity) and adhesives. Material combinations were additionally ranked using AFRs., Results:   A total of 42 studies (6088 restorations, 2325 patients) were included. The ranking of most material class combinations showed significant agreement between classifications ( R 2 ranged between 0.03 and 0.56). Comparing material combinations using AFRs had low precision and agreement with other systems. AFRs were significantly correlated with follow-up periods of trials., Conclusion:   There was high agreement between rankings of identical materials in different classification systems. Such rankings thus allow cautious deductions as to the performance of a specific material. Syntheses based on AFRs might lead to erroneous results because AFRs are determined by follow-up periods and have low precision.

Objective: To provide a reference for a suitable alternative treatment choice for implant-supported prostheses, and to explore the influence of 3 types of prosthetic material on the stress distribution around implant. Methods: The implant-abutment analogs were embedded individually into photoelastic resin blocks, which were medical pure titanium castings reproducing the surface and outline of implant (diameter 4.3 mm, length 11.5 mm) and esthetic abutment (regular profile, 1 mm). The prostheses were divided into 3 groups according to the type of prosthetic material. Each group consisted of 5 samples. The samples of composite resin ceramic and zirconia group were milled by chair-side computer aided design and computer aided manufacture (CAD/CAM) system. The samples of porcelain-fused-to-metal crown group were made manually and a pre-arranged silicone rubber impression of CAD/CAM crown would guide to shape the veneer porcelain. Each set was submitted to a 300 N compressive load axially or obliquely (75°). The stress value in the peri-implant bone at the level of the neck, neck1/3, middle1/3 and root1/3 of the sections (0.5, 1.5, 2.5, 3.5 mm) from implant was analyzed by digital photoelasticity, and the stress cushioning effect of 3 types of prosthetic material was comprehensively evaluated. Results: The time spent reaching the stress peak of composite resin ceramic group [(1.58±0.08) s, axially; (2.75±0.21) s, obliquely] was larger than that of the zirconia group [(1.40±0.12) s, axially; (2.30±0.25) s, obliquely] ( P< 0.05) under the same download mode. Although there were no significant differences in equivalent stress values of the measurement points among the three groups ( P> 0.05), a downward trend of equivalent stress values of composite resin ceramic group was observed compared to zirconia group, regardless of load type. When loaded obliquely, the highest degree of stress concentration at the level of the neck of implant were found in the porcelain-fused-to-metal crown group. Conclusions: Within the limitations of this study, composite resin ceramic was more beneficial to the biomechanical behavior of implant in stress buffer compared to zirconia.

Objectives: This study aimed to evaluate the quality of posterior restorations (amalgam or composite) placed in adults from a birth cohort and its association with clinical and socioeconomic determinants experienced during their life course., Methods: A representative sample (n=539) of all 5914 births occurring in Pelotas (Brazil) in 1982 was prospectively investigated. Quality of posterior restorations (satisfactory or unsatisfactory) was assessed at 31 yrs-old, using modified USPHS criteria. Trained and calibrated dentists performed clinical examination. Explanatory variables included demographic and socioeconomic, oral health and dental service utilization patterns during the life course. Tooth related variables (type of tooth, material, size of cavity) were also analyzed. Untreated caries and socioeconomic status were assessed by group-based trajectories analyses. Multilevel Regression models were used to determine factors associated with restoration outcomes., Results: In total 2123 restorations (53% composite) were evaluated of which 107 (5%) were assessed as failed. The main reasons for failure were tooth/restoration fracture (50.5%) and secondary caries (30.7%). Failures in posterior restorations showed a significant association with socioeconomic aspects (lower tertile of income at age 30 - prevalence ratio (PR) 2.21 [95% CI 1.19-4.09]), clinical variables (trajectory of higher untreated caries - PR 2.11 [95% CI 1.23-3.61]) and also with tooth-related factors (Restorations involving three or more surfaces - PR 5.51 [95% CI 3.30-9.19]) after adjustment for each other., Conclusions: These findings suggest that, although tooth-related variables have an important role in restoration longevity, patient-related factors, such as socioeconomic variables and untreated caries are also associated with failure and should be taken into account when evaluating longevity of posterior restorations., Clinical Significance: This was the first study assessing long-term trajectory of untreated caries, showing an association between higher experience of caries during the life-course and unsatisfactory restorations. The findings suggest that individual related factors should be considered when planning treatment and in future research evaluating the longevity of dental restorations., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Objectives: This study aims at evaluating and comparing mechanical, chemical, and cytotoxicological parameters of a commercial brand name composite material against two 'own brand label' (OBL) composites., Methods: Parameters included depth of cure, flexural strength, degree of conversion, polymerization shrinkage, filler particle morphology and elemental analyzes, Vickers hardness, surface roughness parameters after abrasion, monomer elution, and cytotoxicity., Results: The conventional composite outperformed the OBLS in terms of depth of cure (p<0.001), degree of cure at the first and last time intervals (p<0.001), hardness (p<0.001), and post-abrasion roughness (p<0.05). The polymerization volumetric shrinkage ranged from 2.86% to 4.13%, with the highest shrinkage seen among the OBLs. Both Monomer elution from the OBLs was statistically significantly higher (p<0.001). Statistically significantly higher cytotoxicity combined with altered morphology and loss of confluence was detected in the cells exposed to extracts from the OBLs., Conclusions: The OBLs were in general outdone by the conventional composite., Clinical Significance: OBLs restorative materials have become pervasive in the dental market. Manufacturers often promise equal or better characteristics than existing brand-name composites, but at a lower price. Dentists are highly recommended to reconsider utilization of OBLs lacking sound scientific scrutiny, and our findings underscore this recommendation., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Older adults are retaining an increasing number of natural teeth, and nearly half of all individuals aged 75 and older have experienced root caries. Root caries is a major cause of tooth loss in older adults, and tooth loss is the most significant negative impact on oral health-related quality of life for the elderly. The need for improved preventive efforts and treatment strategies for this population is acute.

The indications for and composition of today's dental ceramic materials serve as the basis for determining the appropriate class of ceramics to use for a given case. By understanding the classifications, composition, and characteristics of the latest all-ceramic materials, which are presented in this article in order of most to least conservative, dentists and laboratory technicians can best determine the ideal material for a particular treatment.

Classification systems for all-ceramic materials are useful for communication and educational purposes and warrant continuous revisions and updates to incorporate new materials. This article proposes a classification system for ceramic and ceramic-like restorative materials in an attempt to systematize and include a new class of materials. This new classification system categorizes ceramic restorative materials into three families: (1) glass-matrix ceramics, (2) polycrystalline ceramics, and (3) resin-matrix ceramics. Subfamilies are described in each group along with their composition, allowing for newly developed materials to be placed into the already existing main families. The criteria used to differentiate ceramic materials are based on the phase or phases present in their chemical composition. Thus, an all-ceramic material is classified according to whether a glass-matrix phase is present (glass-matrix ceramics) or absent (polycrystalline ceramics) or whether the material contains an organic matrix highly filled with ceramic particles (resin-matrix ceramics). Also presented are the manufacturers' clinical indications for the different materials and an overview of the different fabrication methods and whether they are used as framework materials or monolithic solutions. Current developments in ceramic materials not yet available to the dental market are discussed.

Dental restoration begins with removing carries and affected tissues with air-turbine rotary cutting handpieces, and later restoring the lost tissues with appropriate restorative materials to retain the functionality. Most restoration materials eventually fail as they age and need to be replaced. One of the difficulties in replacing failing restorations is discerning the boundary of restorative materials, which causes inadvertent removal of healthy tooth layers. Developing an objective and sensor-based method is a promising approach to monitor dental restorative operations and to prevent excessive tooth losses. This paper has analyzed cutting sounds of an air-turbine handpiece to discriminate between tooth layers and two commonly used restorative materials, amalgam and composite. Support vector machines were employed for classification, and the averaged short-time Fourier transform coefficients were selected as the features. The classifier performance was evaluated from different aspects such as the number of features, feature scaling methods, classification schemes, and utilized kernels. The total classification accuracies were 89% and 92% for cases included composite and amalgam materials, respectively. The obtained results indicated the feasibility and effectiveness of the proposed method.

Resin-based composites are an integral component of contemporary pediatric restorative dentistry. They can be utilized effectively for preventive resin restorations, moderate Class II restorations, Class III restorations, Class IV restorations, Class V restorations, and strip crowns. Tooth isolation to prevent contamination is a critical factor, and high-risk children may not be ideal candidates for resin-based composite restorations. Important factors to consider during composite placement are isolation, polymerization shrinkage, and extent of restoration. When utilized correctly, resin-based composites can provide excellent restorations in the primary and permanent dentition. The purpose of this paper was to update previous publications that addressed the use of resin-based composites in children with accepted recommendations through a Pediatric Restorative Dentistry Consensus Conference.

Dental materials, especially in restorative dentistry, must not only be cost-effective, they must also meet many other requirements: biocompatibility, durability, excellent shade and light effects, abrasion resistance, hardness, mechanical strength under pressure, chemical resistance, surface density, ease of manufacture, and easy intraoral maintenance.

Purpose: The execution of adjustments on ceramic restorations is sometimes necessary for either correction of occlusion and/or inadequate contours or esthetical improvements. Clinically, the surfaces undergo weariness through fine grinding diamond burs which remove the superficial glazing layer. Several materials for ceramic polishing have been used in an attempt to reach a satisfactory surface smoothness. The aim of this study was to perform a literature review on different polishing protocols of several dental ceramics., Study Selection: This is a literature review performed through scientific articles published between 2004 and 2012, indexed in MEDLINE, PubMed and Scielo databases. The study selected and analyzed a total of 20 relevant articles that evaluated different types of ceramics, polishing treatment and surface roughness., Results: After an extensive literature review, this study observed: 1 - after the rupture of the glazing layer due to the adjustments of the restorations, the best choice for the polishing of the surface will depend on the type of ceramics used; 2 - glazing procedure provide excellent results regarding to the superficial smoothness; however, if reglazing is impossible, either abrasive rubber cups/points or sandpaper discs followed by the use of diamond polishing pastes results in a satisfactory superficial smoothness; 3 - clinical studies that take into account the behavior of the protocols polishing are scarce and should be encouraged; 4 - the large number of variables influence the final outcome of polishing should be considered., Conclusions: The necessity in standardization of methodologies to enable a comparison among researches., (Copyright © 2014 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.)

Objectives: This study aimed to evaluate posterior restorations placed in young adults, investigating the association between social determinants experienced during the life course and the quality of tooth fillings., Methods: A representative sample (n=720) of all 5914 individuals who were born in Pelotas in 1982 was prospectively investigated, and posterior restorations were assessed at 24 years of age. Exploratory variables included demographic and socioeconomic, oral health and dental service payment mode during the life course. Tooth-related variables (type of tooth, material and size of cavity) were also analysed., Results: Multilevel logistic regression models showed that individuals who were always poor from birth to age 23 [odds ratio (OR) 2.35 (1.38-4.00)] and whose mothers had less years of education at their birth (OR 2.60 (1.44-4.68)) were with unsatisfactory restorations in posterior teeth more often. In addition, caries presence at age 15 (high decayed, missing, filled teeth (DMFT) tertile) (OR 1.95 (1.25-3.03)) and cavities with four or more surfaces (OR 18.67 (9.25-37.68)) were associated with the outcome., Conclusions: These results show that socioeconomic characteristics of the individuals play an important role in restoration failures, reinforcing the need for preventive dental strategies and public policies to reduce inequalities as a major topic of oral health. In addition, the size of cavity appears as the most important determinant for restoration failure., Clinical Significance: Individual socioeconomic characteristics were associated with failure in posterior restorations in detriment of other clinical variables such as restorative material and type of tooth., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

As the economy has receded in recent years, many patients have been inclined to reject dental treatment beyond what they feel is the minimal amount necessary. Increasingly, there has been reluctance to take on the expense of full-mouth restorations and time-consuming procedures. Consequently, clinicians can benefit from innovative, conservative, interim solutions that enable them to provide segment treatment with long-term stability and esthetics, with lower initial cost. The bonded functional esthetic prototype (BFEP) allows fabrication of up to 14 teeth from composite in 1 hour, providing either a pre-treatment restoration or a long-term provisional solution until further treatment can be completed. As demonstrated herein, the BFEP enables superb function, stability, and esthetics in the interim while dispersing the cost of definitive treatment over time.

Many restorative dentists cobble together materials and techniques from different manufacturers to create systems that work for their clinical needs. The author proposes that it may be possible to improve outcomes and continue toward excellence by selecting the ideal restorative solution with materials designed, tested, and intended to be used together. DENTSPLY Caulk's Class II solution is examined in this article as a means for helping in placement of posterior restorations, namely Class II restorations. A case report is explored.

Objectives: The study analyzed the reparability and compatibility of light-curing resin-based composites (RBCs) of the categories "microhybrid," "nanohybrid," and "packable.", Materials and Methods: Six RBCs with different matrix and filler formulation--purely methacrylate-based composites (MBCs), ormocer-based composites (OBCs), and silorane-based composites (SBCs)--were used for the specimens. Every material was combined with itself and with the other five RBCs, resulting in a total of 36 combination groups (n = 20). The specimens were polymerized, aged for 8 weeks in distilled water at 37 °C, and then repaired by means of a repair kit. Shear bond strength and fracture mode were measured after aging of the specimens, undergoing storage for 24 h in distilled water at 37 °C followed by thermocycling (5,000 cycles, 5-55 °C) and an additional 4-week storage in distilled water at 37 °C., Results: Data were statistically analyzed using ANOVA with TUKEY HSD post hoc test (α = 0.05). On average, the OBC Admira reached the highest value as a substrate material (30.41 MPa), and the SBC Filtek Silorane reached the lowest value (8.14 MPa). Filtek Silorane was identified as the repair material with the highest bond strength value (28.70 MPa), while a packable composite reached the lowest bond strength value (15.55 MPa). The analysis of the break modes showed that adhesive breaks are typical when strength is at its lowest (6.27 MPa). A large number of cohesive fractures are conspicuous when identical materials are used for repair, except Filtek Silorane (2 % cohesive fractures)., Conclusions: The study demonstrated that the effect of the different materials on bond strength varies strongly, depending on whether the material is used as filling or as repair material., Clinical Relevance: It is generally advisable but not compulsory to combine identical RBCs.

In the past few decades, there has been an increase in demand for safety evaluation and control of dental materials used daily in dentistry; however, this task is difficult and cumbersome. Dental materials that are passive and do not react with the oral environment will be more stable and have superior durability. It is expected that dental materials will be universally accepted and will not cause harm or injury to the surrounding structures in the oral cavity. This is an entirely negative approach to the material tolerance and biocompatibility, and hides the possibility that some positive gains can be achieved. Side-effects of dental materials are believed to be rare, and generally, those that have been reported are mild. There are wide varieties of materials used in dentistry, which include liners, irrigants, intracanal filling materials, intracanal medicaments, prosthetic materials, restorative materials, subgingival implants, and mouth rinses. Therefore, in this study, the biocompatibility of various commonly-used clinical materials used in contemporary dentistry was discussed., (© 2012 Wiley Publishing Asia Pty Ltd.)

This literature review summarizes the published research regarding the antibacterial agents used in adhesive dentistry. This article provides information about the clinical applications, beneficial effects, and possible disadvantages of antibacterials when used in various bonding situations.

The practice of operative dentistry continues to evolve, to reflect the many changes occurring in society and in dental diseases and conditions. However, the belief that all questionable and early carious lesions should be restored still persists. This belief is largely based upon the concept that the removal of all carious tissue followed by meticulous restoration of the tooth is the treatment of choice for dental caries. Yet restorations are not permanent and do not cure caries, as the causes remain. On the other hand, preventive measures can remove or partially remove the causes, thereby reducing the risks for future caries recurrence at the same site or elsewhere in the mouth.

Molar Incisor Hypomineralization (MIH) is a common condition in New Zealand children and children around the world and can result in a significant defect in first permanent molars. This condition inevitably leads to a large amount of dental treatment for young children and may even result in the removal of their first permanent molars. This lecture will outline the understanding of the physical properties of these teeth and provide an evidence based review of the treatment options for affected teeth.

Objectives: To evaluate whether occlusoproximal restorations with cervical margins apical to the cemento-enamel junction (CEJ) are more prone to failure than restorations with margins coronal to the CEJ, in particular failure due to secondary caries., Methods: A method was developed for scoring cervical margin extension on bitewings, and validated in vitro. Records from patients with at least one occlusoproximal restoration replaced due to secondary caries were selected from an existing database. Cervical margins of approximal restoration sites were scored on bitewings in relation to the CEJ (supra vs. sub CEJ). For all restorations dates of placement, replacement and reason for failure were recorded. Survival times were calculated and Cox-regression analysis was applied to assess influence of selected variables on survival of restorations: extension of cervical margins, number of restored surfaces, restoration material and age of the patient., Results: Records of 84 patients with 1912 restoration sites were examined, 655 failed; 399 supra CEJ and 256 sub CEJ. 257 restorations failed because of secondary caries. Restorations ending below the CEJ showed significantly increased risk for failure (HR=1.28, p=0.020), however, no relation with secondary caries was found (p=0.130). Amalgam restorations showed decreased risk for secondary caries (HR=0.51, p<0.001)., Conclusion: Occlusoproximal restorations with cervical margins apical to the CEJ do not fail more often due to secondary caries. However, those restorations did show larger risk of failure overall compared to restorations with margins coronal to the CEJ. Resin composite restorations showed increased risk for secondary caries compared to amalgam restorations., Clinical Significance: Within the limitations of this study, no association was found clinically between extension of restoration margins below the CEJ and the occurrence of secondary caries., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Introduced more than some 50 years ago, composite resin technology has simplified the manner in which clinicians practice restorative dentistry, offering greater predictability and improved physical properties. Decades of material science and laboratory development along with clinical trials in human subjects have culminated in composite resin being validated as a reliable, multifunctional restorative material. With a wide range of composite resins available today, clinicians can benefit from knowing the infrastructure of a given material in order to determine which type will work best in a particular clinical situation.

Background: The authors conducted a study to quantify the reasons for restoring noncarious tooth defects (NCTDs) by dentists in The Dental Practice-Based Research Network (DPBRN) and to assess the tooth, patient and dentist characteristics associated with those reasons., Methods: Data were collected by 178 DPBRN dentists regarding the placement of 1,301 consecutive restorations owing to NCTDs. Information gathered included the main clinical reason, other than dental caries, for restoration of previously unrestored permanent tooth surfaces; characteristics of patients who received treatment; dentists' and dental practices' characteristics; teeth and surfaces restored; and restorative materials used., Results: Dentists most often placed restorations to treat lesions caused by abrasion, abfraction or erosion (AAE) (46 percent) and tooth fracture (31 percent). Patients 41 years or older received restorations mainly because of AAE (P < .001). Premolars and anterior teeth were restored mostly owing to AAE; molars were restored mostly owing to tooth fracture (P < .001). Dentists used directly placed resin-based composite (RBC) largely to restore AAE lesions and fractured teeth (P < .001)., Conclusions: Among DPBRN practices, AAE and tooth fracture were the main reasons for restoring noncarious tooth surfaces. Pre-molars and anterior teeth of patients 41 years and older are most likely to receive restorations owing to AAE; molars are most likely to receive restorations owing to tooth fracture. Dentists restored both types of NCTDs most often with RBC.

Background: Identifying disaster victims by means of dental records is a well-established technique. In cases in which high temperatures are involved, destruction of the structural relationship of the dentition necessitates that adjunctive aids be used in the identification process. Analysis of tooth fragments by means of scanning electron microscopy with energy dispersive x-ray spectroscopy can reveal evidence of restorative procedures, as well as trace amounts of dental materials remaining on tooth surfaces. In addition, dental materials can be analyzed and identified according to brand, even if the materials have been cremated., Case Description: The authors describe the identification of three victims from the crash of Colgan Air flight 3407, a commuter airplane flying between Newark, N.J., and Buffalo, N.Y. The crash involved a fire, and a portion of the airplane burned for nearly 11 hours. Dental fragments that had restorative material adhering to them were recovered and analyzed. These fragments contained corroborative information that helped confirm the identity of the victims., Clinical Implications: Detailed record keeping is part of clinical practice. The level of detail present in dental records can affect the ability of forensic odontologists to determine the identity of a victim's remains. Documenting the brand names of dental materials used in restorative procedures can make the difference between identifying and not identifying a victim's remains.

The prosthetic treatments play a role in the rehabilitation of patients with congenital and acquired cleft palate. To prepare the surgical field and/or correct inevitable sequelae of the surgery, the rehabilitation with obturator prosthesis is an auxiliary or complementary treatment to surgical treatments. In cases where the surgical treatment is contraindicated, the prosthetic rehabilitation becomes a definitive treatment. The denture is planned and fabricated according to each patient. Therefore, the aim of this study was to discuss the prosthetic rehabilitation performed in patients with oronasal communication.

Objectives: The objective is to review the current state of the art of dental composite materials., Methods: An outline of the most important aspects of dental composites was created, and a subsequent literature search for articles related to their formulation, properties and clinical considerations was conducted using PubMed followed by hand searching citations from relevant articles., Results: The current state of the art of dental composites includes a wide variety of materials with a broad range of mechanical properties, handling characteristics, and esthetic possibilities. This highly competitive market continues to evolve, with the major emphasis in the past being to produce materials with adequate strength, and high wear resistance and polishability retention. The more recent research and development efforts have addressed the issue of polymerization shrinkage and its accompanying stress, which may have a deleterious effect on the composite/tooth interfacial bond. Current efforts are focused on the delivery of materials with potentially therapeutic benefits and self-adhesive properties, the latter leading to truly simplified placement in the mouth., Significance: There is no one ideal material available to the clinician, but the commercial materials that comprise the current armamentarium are of high quality and when used appropriately, have proven to deliver excellent clinical outcomes of adequate longevity., (Copyright © 2010 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.)

Unlabelled: Stress generation at tissue/resin composite interfaces is one of the important reasons for failure of resin-based composite (RBC) restorations owing to the inherent property of polymerization shrinkage. Unrelieved stresses can weaken the bond between the tooth structure and the restoration, eventually producing a gap at the restoration margins. This can lead to postoperative sensitivity, secondary caries, fracture of the restorations, marginal deterioration and discoloration. As polymerization shrinkage cannot be eliminated completely, various techniques and protocols have been suggested in the manipulation of, and restorative procedures for, RBCs to minimize the shrinkage and associated stresses. Introduction of various newer monomer systems (siloranes) may also overcome this problem of shrinkage stress. This review emphasizes the various material science advances and techniques advocated that are currently available or under trial/testing phase to deal with polymerization shrinkage in a clinical environment., Clinical Relevance: Minimizing the shrinkage stresses in RBC restorations may lead to improvement in the success rate and survival of restorations. Thus, it is important for dental practitioners to be aware of various techniques and materials available to reduce these shrinkage stresses and be updated with the current knowledge available to deal with this issue.

Objectives: The purpose of this study was to determine the optical properties, color and translucency, of the new silorane-based resin composite and to compare it to universal dimethacrylate-based composites., Methods: Six dimethacrylate-based resin composites and one silorane-based resin composite (all A2 shade) were studied. Color of non-polymerized and polymerized composites was measured against white and black backgrounds using a spectroradiometer. Changes in color (ΔE*(ab)), translucency (ΔTP) and color coordinates (ΔL*, Δa* and Δb*) were calculated for each resin composite. Results were evaluated using a one-way ANOVA, a Tukey's test and a t-test., Results: The polymerization-dependent ΔE*(ab) ranged from 4.7 to 9.1, with the smallest difference for the silorane-based resin composite. The color changes of silorane-based composite were due to the changes of coordinates Δa* and Δb*. However, for the dimethacrylate-based composites, the color changes mainly originated by ΔL*and Δb*. The silorane composite exhibited the smallest TP values. Tukey's test confirmed significant statistical differences (p<0.05) between mean TP values of Filtek Silorane and each brand of dimethacrylate-based composites before and after polymerization., Conclusions: The new silorane-based restorative system showed different optical properties compared to clinically successful dimethacrylate composites. The silorane composite exhibited better polymerization-dependent chromatic stability, and a lower translucency compared to other tested products., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

Purpose: The original ceramic surface finish and its microstructure may have an effect on crack propagation. The purpose of this study was to investigate the relation between crack propagation and ceramic microstructure following cyclic fatigue loading, and to qualitatively evaluate and quantitatively measure the surface and subsurface crack depths of three types of ceramic restorations with different microstructures using a Confocal Laser Scanning Microscope (CLSM) and Scanning Electron Microscope (SEM)., Materials and Methods: Twenty (8 x 4 x 2 mm(3)) blocks of AllCeram (AC), experimental ceramic (EC, IPS e.max Press), and Sensation SL (SSL) were prepared, ten glazed and ten polished of each material. Sixty antagonist enamel specimens were made from the labial surfaces of permanent incisors. The ceramic abraders were attached to a wear machine, so that each enamel specimen presented at 45 degrees to the vertical movement of the abraders, and immersed in artificial saliva. Wear was induced for 80K cycles at 60 cycles/min with a load of 40 N and 2-mm horizontal deflection. The specimens were examined for cracks at baseline, 5K, 10K, 20K, 40K, and 80K cycles., Results: Twenty- to 30-microm deep subsurface cracking appeared in SSL, with 8 to 10 microm in AC, and 7 microm close to the margin of the wear facets in glazed EC after 5K cycles. The EC showed no cracks with increasing wear cycles. Seventy-microm deep subsurface cracks were detected in SSL and 45 microm in AC after 80K cycles. Statistically, there was significant difference among the three materials (p < 0.05). Bonferroni multiple comparison of means test confirmed the ANOVA test and showed that there was no statistical difference (p > 0.05) in crack depth within the same ceramic material with different surface finishes., Conclusions: The ceramic materials with different microstructures showed different patterns of subsurface cracking.

The Er:YAG laser has an active medium of Yttrium-Aluminium-Garnet doped with Erbium ions and emits free-running pulsed laser energy at a wavelength of 2940 nm. The Er,Cr:YSGG laser has an active medium of Yttrium-Scandium-Gallium-Garnet doped with Erbium and Chromium ions and emits free-running pulsed laser energy at a wavelength of 2780 nm. These wavelengths have a high absorption in water, which makes their application appropriate for ablating oral soft tissue as well as dental hard tissue. This article examines the principles of use for the Er:YAG and Er,Cr:YSGG lasers in clinical restorative dentistry and reviews the literature regarding different aspects of the use of laser energy on hard tissues.

Statement of Problem: Plaque on dentures may foster the occurrence of denture stomatitis and periodontal diseases in gingival tissues adjacent to partial dentures. Thus, it is beneficial for dental materials to have a low susceptibility to plaque adhesion., Purpose: The purpose of this study was to evaluate the susceptibility of commonly used artificial teeth to adhesion of the oral bacterium Streptococcus mutans., Material and Methods: Fifteen specimens each of 12 different artificial teeth were prepared by cutting standardized slabs from the buccal tooth surfaces. After normalizing size (round specimens, diameter of 5 mm, 2 mm thick), polishing (grinding paper, grain 1000 and 4000; universal polishing paste), and assessing surface roughness with a profilometric contact surface measurement device, specimens were incubated with Streptococcus mutans NCTC 10449 suspension for 2.5 hours at 37 degrees C. A veneering composite resin (Sinfony) was used as a control. Adherent bacteria were quantified using a fluorometric assay (Resazurin reduction); relative fluorescence intensity correlates linearly with the number of adherent bacteria. Medians and 25%/75% percentiles were calculated, and statistical analysis was performed using the Kruskal-Wallis test and the Bonferroni-adjusted Mann-Whitney U test., Results: The highest values, indicating high adhesion of streptococci, were observed for filler-supplemented teeth with median relative fluorescence values ranging from 6356 to 18,770. Similar values were recorded for a double cross-linked resin tooth (6444). Significantly lowest values, ranging from 1173 to 3974, were found for unfilled PMMA acrylic resin teeth and acrylic resin teeth with an interpenetrating network (1436)., Conclusions: Within the limitations of this study, it can be concluded that the adhesion of Streptococcus mutans to unfilled PMMA teeth and teeth with an interpenetrating network is lower than adhesion to artificial teeth supplemented with fillers or double cross-linked acrylic resin teeth.

Adhesive procedures are essential to most restorative protocols used in modern dentistry. Increasing demand and constant interest in new products have stimulated dental manufacturers to produce new adhesive systems and marketing campaigns that announce fast and easy bonding. However, laboratorial and clinical studies show that, usually, ease of application of an adhesive system does not relate to its competence in creating a quality, long-term adhesive interface. This article will present relevant data from the scientific literature to help clinicians understand quality adhesion and achieve excellent results with the current adhesion systems.

This article presents the essential aspects for understanding and reproducing the color of natural teeth with the use of direct resin composite. Fluorescence and opalescence are discussed, with special emphasis on counter-opalescence, which is primarily responsible for the appearance of an orange discoloration at the mamelon dentin tips and incisal edges of anterior teeth. The dynamics of color in natural teeth in relation to age is also discussed, focusing on the age-related changes that occur in enamel, dentin, and pulp. Further, it is demonstrated how to reproduce the esthetic features of natural teeth using latest-generation direct resin composites.

The purpose of this study was to determine the combined effect of an organic substance (mucin as a substitute for salivary organic substances), chlorhexidine, and an iron compound/tea solution on the changes in the color of esthetic Class V dental restorative materials. Color of a glass ionomer, resin-modified glass ionomer, compomer and flowable resin composite of A2 shade, respectively, was determined according to the CIELAB color scale relative to the standard illuminant D65. Color was measured at baseline, and after sequential immersion in the following substances: Step-1, mucin in PBS (MCP) for 48 h; Step-2, chlorhexidine (CHX) for 24 h; Step-3, iron compound (IRN) or tea solution (TEA) up to 7 days; and Step-4, ultrasonic cleaning for 1 h. Color change (DeltaE(ab )*) was calculated by the equation: DeltaE(ab)* = [(DeltaL*)(2) + (Deltaa*)(2) + (Deltab*)(2)](1/2), of which DeltaL(*) indicates changes in value, Deltaa(*) indicates changes in red-green parameter and Deltab(*) indicates changes in yellow-blue parameter. DeltaE(ab)* values after immersion in MCP and CHX were compared, and DeltaE(ab)* values after immersion in IRN or TEA, and subsequent ultrasonic cleaning were compared with respect to the restorative material and immersion substance. DeltaE(ab)* and changes in the color parameters (DeltaL(*), DeltaC(ab)* and DeltaH(ab)*) were analyzed by repeated measures, analysis of variance and a post-hoc test at the 0.05 level of significance. Color changes after immersion in MCP were acceptable (DeltaE(ab)* < 3.3), and those after immersion in CHX were generally acceptable. The range of DeltaE(ab)* values after immersion in IRN was 3.1-19.6, and that after ultrasonic cleaning was 2.4-9.6. The range of DeltaE(ab)* values after immersion in TEA was 10.7-21.1, and that after ultrasonic cleaning was 11.9-14.5. Color changes of four Class V restorative materials after combined treatment with mucin, chlorhexidine and an iron compound/tea solution were not acceptable. Colors did not recover to their original values after ultrasonic cleaning. Modifications on the surface of a restoration should be considered to reduce stain accumulation.

The Food and Drug Administration (FDA) is reclassifying tricalcium phosphate (TCP) granules for dental bone repair from class III to class II (special controls), classifying into class II (special controls) other bone grafting material for dental indications, and revising the classification name and identification of the device type. Bone grafting materials that contain a drug that is a therapeutic biologic will remain in class III and continue to require a premarket approval application. The classification identification includes materials such as hydroxyapatite, tricalcium phosphate, polylactic and polyglycolic acids, or collagen. This action is being taken to establish sufficient regulatory controls that will 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 class II devices.