Search

Purpose: The objective of this systematic review is to compare results concerning the properties of adhesion, roughness, and hardness of dental liners obtained in the last ten years., Methods: Searches on the databases LILACS, PubMed/Medline, Web of Science, and Cochrane Database of Systematic Reviews were supplemented with manual searches conducted between February and April of 2018. The inclusion criteria included experimental in vitro and in vivo , clinical, and laboratory studies on resilient and/or hard liners, assessment of hardness, roughness, and/or adhesion to the denture base, and physical/mechanical changes resulting from the disinfection process and changes in liners' composition or application., Results: A total of 406 articles were identified and, from those, 44 are discussed. Twenty-four studies examined the bond strength, 13 surface roughness, and 19 the hardness. Of these 44 studies, 12 evaluated more than one property. Different substances were used in the attempt to improve adhesion. Considering roughness and hardness, the benefits of sealants have been tested, and the changes resulting from antimicrobial agents' incorporation have been assessed., Conclusion: Adhesion to the prosthesis base is improved with surface treatments. Rough surfaces and changes in hardness compromise the material's serviceability.

Background Teeth restored with direct composite resin are constantly exposed to specific challenges of the oral cavity. These challenges can modify the material properties and, when associated with daily brushing, eventually change its surface roughness, allowing bacterial growth and retention of extrinsic pigments. Dentifrices plays an important role in dental wear (abrasion) and over time, can also cause an increase in the surface roughness of restorative materials. Objective To assess the effect of dentifrices on the longevity of direct nanofilled composite resins restorations as far as wear and roughness is concerned. Method Class V cavity were prepared on 90 extracted human teeth and restored with Filtek Z350 composite. Teeth were randomly divided into 6 experimental groups of 15 each labelled as Group-1 (Colgate Dental cream) Group-2 (Colgate Active Salt toothpaste), Group-3 (Pepsodent Regular toothpaste), Group-4 (Dabur red toothpaste), Group-5 (Dabur Lal tooth powder) and Group-6 Control (water). The samples were fixed on tooth brushing machine and subjected to mechanical tooth brushing using various dentifrices according to respective groups in 3 phases and reading of surface roughness (Ra) was recorded. Result Surface roughness (Ra) had increased in following order: Group 6 < Group 3 < Group 2 < Group 1 < Group 4 < Group 5. All the tooth pastes were compared, their behaviour was found to be similar as there was no statistically significant difference amongst them. Though all of them were inferior to control group and the difference was statistically significant. Whereas the only tooth powder Dabur lal tooth powder gave the maximum roughness when compared with the other tooth pastes and the difference was statistically significant. Conclusion With increase in time of brushing there was increase in surface roughness in all the 5 dentifrices among them Ra was maximum for Dabur lal tooth powder.

Background: The purpose of this study was to investigate the effects of staining solutions and surface finishing on the colour stability and translucency of hybrid ceramic (HC) and resin nanoceramic (RNC) materials., Methods: Twenty four groups consisting of 10 specimens (240 specimens in total) were created out of HC and RNC, including six groups to be stored in distilled water served as the controls groups. The Vita Enamic technical set, Shofu polishers, medium and fine rubber wheels and Sof-Lex polishing discs were used as polishing instruments. Cola, tea, and coffee were used as staining solutions. The colour differences (∆E*) and translucency parameter (TP) were evaluated by a spectrophotometer. Data were analysed by a One-way Analysis of Variance (ANOVA) and Mann-Whitney U test., Results: There was a statistically significant difference between the ∆E* values of the HC specimens in the coffee groups and the ∆E* values of the other HC groups (p < 0.05). The ∆E* values of the RNC specimens in the coffee and tea groups were not different from the specimens in the cola groups (p > 0.05). The TP values of the polished groups were higher than the Sof-Lex groups and the Shofu groups on both HC and RNC materials (p < 0.05)., Conclusions: Increased ∆E* values were observed in HC specimens stored in a coffee solution compared to the specimens stored in a tea or cola solution. Both of the RNC specimens stored in coffee and tea had higher ∆E* values than the RNC specimens stored in the cola. The TP values of both HC and RNC specimens stored in the coffee solution decreased.

Aim: The purpose of this study is to evaluate the clinical performance of three different restorative materials in primary teeth according to the FDI criteria., Materials and Methods: Resin-modified glass ionomer cement, compomer and composite resin restorations (n=93) were made in 31 patients. The restorations were clinically evaluated at baseline, 6th, 12th and 18th month with the FDI criteria., Results: The cumulative survival rate after 18 months was found to be 90.3% for resin modified glass ionomer cement restorations, 100% for compomer restorations and 80.6% for composite resin restorations. Statistically significant increase in surface roughness, colour mismatch, anatomic form loss and marginal deterioration were detected in resin- modified glass ionomer group (p<0.05). The most frequent reason for restoration failure in composite resin group was restoration fractures., Conclusions: The resin-modified glass ionomer restorations necessitates close follow-up because of the risk of increase in surface roughness, changes in colour and loss in anatomic form and marginal adaptation. The clinical performance of compomer restorations is superior to resin-modified glass ionomer and composite resin restorations in primary teeth.

Background: Children consume foods that are colorful which contain food additives that stain not only the tooth structure but also the restorations. As esthetics is of prime concern for both parents and children nowadays, long-term color stability of restorative materials is of utmost importance., Aim: To evaluate the color stability of two tooth-colored restorative materials (conventional glass ionomer cement [GIC] and giomer) when immersed in various consumable drinks and food (aerated beverage, ice candy, and health drink) at different immersion periods (low, moderate, and high)., Materials and Methods: A total of 100 specimens were made with each restorative material. Ten were used as a control and remaining (n = 90) as experimental. The experimental specimens were divided into three groups based on media of immersion (n = 30 each) and were further divided into three subgroups based on immersion time (n = 10 each). The color changes (ΔE values) were measured using spectrophotometer., Results: Both the tested materials showed color change; however, conventional GIC showed greater ΔE values when compared to giomer and the samples exposed to aerated beverage resulted in highest color change. It is also noticed that greater the exposure time, higher are the ΔE values., Conclusion: Giomer showed more resistance to color change than conventional GIC with all the tested media and immersion regimes.

Applications of proteomics tools revolutionized various biomedical disciplines such as genetics, molecular biology, medicine, and dentistry. The aim of this review is to highlight the major milestones in proteomics in dentistry during the last fifteen years. Human oral cavity contains hard and soft tissues and various biofluids including saliva and crevicular fluid. Proteomics has brought revolution in dentistry by helping in the early diagnosis of various diseases identified by the detection of numerous biomarkers present in the oral fluids. This paper covers the role of proteomics tools for the analysis of oral tissues. In addition, dental materials proteomics and their future directions are discussed.

Aim: To study the outcomes for restored primary molar teeth; to examine outcomes in relation to tooth type involved, intracoronal restoration complexity and to the material used., Design: Retrospective study of primary molar teeth restored by intracoronal restorations. A series of restored primary molar teeth for children aged 6-12 years was studied. The principal outcome measure was failure of initial restoration (re-restoration or extraction). Three hundred patient records were studied to include three equal groups of primary molar teeth restored with amalgam, composite or glass ionomer, respectively. Restorative materials, the restoration type, simple (single surface) or complex (multi-surface) restoration, and tooth notation were recorded. Subsequent interventions were examined. Data were coded and entered into a Microsoft Excel database and analysis undertaken using SPSS v.18. Statistical differences were tested using the Chi square test of statistical significance., Results: Of the 300 teeth studied, 61 restoration failures were recorded with 11 of those extracted. No significant differences were found between outcomes for upper first, upper second, lower first or lower second primary molars. Outcomes for simple primary teeth restored by intracoronal restorations were significantly better than those for complex intracoronal restorations (P = 0.042). Teeth originally restored with amalgam accounted for 19.7% of the 61 failures, composite for 29.5%, while teeth restored with glass ionomer represented 50.8% of all restoration failures. The differences were significant (P = 0.012)., Conclusions: The majority (79.7%) of the 300 restored primary teeth studied were successful, and 3.7% teeth were extracted. Restorations involving more than one surface had almost twice the failure rate of single surface restorations. The difference was significant. Significant differences in failure rates for the three dental materials studied were recorded. Amalgam had the lowest failure rate while the failure rate with glass ionomer was the highest.

Objective: The aim of the study was to compare under in vitro conditions marginal sealing of 4 different bulk-fill materials composite restorations of class II., Methods: Comparative evaluation concerned 4 composites of a bulk-fill type: SonicFill, Tetric EvoCeram Bulk Fill, Filtek Bulk Fill, and SDR. The study used 30 third molars without caries. In each tooth 4 cavities of class II were prepared. The prepared tooth samples were placed in a 1% methylene blue solution for 24 h, and after that in each restoration the depth of dye penetration along the side walls was evaluated., Results: The highest rating (score 0, no dye penetration) was achieved by 93.33% of the restorations made of the SDR material, 90% of restorations of SonicFill system, 86.66% of restorations of the composite Filtek Bulk Fill, and 73.33% of restorations of the Tetric EvoCeram Bulk Fill., Conclusion: The performed study showed that bulk-fill flowable or sonic-activated flowable composite restorations have better marginal sealing (lack of discoloration) in comparison with bulk-fill paste-like composite.

The aim of this review is to evaluate the suitability of rat molar teeth in preclinical evaluation of medical devices for direct pulp capping. The ISO standard 7405 states clearly that only non-rodent mammals are suitable species for animal research in dentistry. Furthermore, without clear justification a considerable number of researchers previously rejected results of animal experiments concerning preclinical evaluation of the biocompatibility of dental materials undertaken in rat molar teeth. However, in the past 50 years about 70 studies have been published using rat molar teeth in order to evaluate direct pulp capping, pulpotomies and tissue reactions after pulp exposure. Numerous studies showed that the healing of rat molar pulp tissue after direct pulp capping is histologically comparable with humans and other animal species pulp tissue. Rat molar teeth, including pulp tissue, can be seen anatomically, histologically, biologically, and physiologically as miniature human molar teeth. Hence, the essential biological reactions of the pulp tissue and the interaction during the different stages of wound healing of rat molar teeth are comparable with that of other mammals. Rat molar teeth are a valid study model in order to provide valuable data concerning pulp tissue reaction after direct pulp capping and related questions in dentistry. Therefore, the use of rats may significantly reduce the number of currently used higher animals in research. Tests in higher developed animals should be limited to experiments which clarify inconsistent results. However, some technical difficulties, like the small size of rat molar teeth must be dealt with before undertaking any research.

Objective: To analyze the use of biomaterials in surgical procedures carried out by specialist dental surgeons, in light of the Principalist Bioethics Theory and the Individual and Collective Ethics of Responsibility., Methods: Dental surgeons (n=95), who were registered as specialists at the Regional Dentistry Council of Brasilia as of 2002, completed questionnaires regarding the use of biomaterials in their work. Data relating to sanitary control were collated, based on these dental surgeons' responses and research at relevant organizations., Results: All of the professionals in the survey used biomaterials on a regular basis; 45% believed their use to be risk-free for patients, and 48% did not classify biomaterials as drugs. About 70% of professionals trust the source of the biomaterials even though membranes and bones are the items most commonly bought from individual suppliers. Nonetheless, 96% of interviewees believed that government sanitation agencies should regulate more. More than half of the professionals (51%) pointed to little or no participation by the patient in the process of therapeutic choice. A copy of the informed consent form was provided by 12% of the dental surgeons interviewed produced., Conclusions: The results showed that the professionals use biomaterials without knowing about related risks and adverse side effects, contrary to the principle of beneficence. Government agencies and professional bodies alike do not show evidence of observing public responsibility ethics. Informed consent is not yet integrated fully into professional practice and the doctor-patient relationship in dentistry remains markedly vertical.

The purpose of this study was to observe the effect of different conditions of storage on the surface and in the depth of luting glass ionomer cement by measuring microhardness. The hardness of a glass ionomer cement was measured after storage in wet and dry conditions and in an atmosphere of 80% relative humidity, for times up to 1000 h. Storage in distilled water produced a softening effect, but the depth hardness increased progressively. The penetration of the water is a surface phenomenon and does not affect the depth of the cement. However, the cement is vulnerable to moisture to a depth of 600 microns and marginal gaps evolve in the range of 40 to 80 microns when the luting cement at the tooth crown margin is always destroyed.

Porosity in the pastes of composite resins before and after polymerization has been measured. The influence of the diameter of the extrusion orifices and the spatulation of the chemically-activated pastes has been evaluated. Considering that thin layers of these materials are transparent, the investigation has been carried out mainly by analysis of approximately 300 microns or lower thickness layers, that are still transparent under the microscope. Generally, there was a significant dependence of the porosity on the orifice diameter. However, this rule showed some exceptions. As far as the chemically-activated pastes were concerned, in all examined cases the number of small size (10-40 microns) porosities increased after spatulation.

The accuracy of rubber impression materials was evaluated by taking impressions of a steel model, pouring it with stone and comparing certain measurements between steel and stone models. It is assumed that acceptance is achieved when the difference in measurements is within permissible limits, defined by clinical criteria. A mathematical formulation of these criteria will lead to the concept of probability of acceptance. The probability is affected when the limits are changed. The particular case of satisfying two acceptance criteria that contain variables which are not statistically independent is considered, leading to the application of the bivariate normal distribution in the evaluation of acceptance probability.

Five dental direct filling materials were tested in tension and compression in order to define their stress-strain behaviour for both types of applied stress. In addition, fracture toughness was determined from three-point bending tests. Linear and non-linear stress-strain behaviour was observed, and the response was specific for each material and also to the type of applied stress. Fracture resistance was also found to be material specific, which was related to differences in composition.

The spectrophotometric method of colour measurement was applied to an investigation of the colour stability of dimethacrylate based composite resins exposed to thermal and photochemical aging. A good correlation was observed between visual perception of colour change and the spectrophotometric colour difference [delta E (FMC-2)] of unexposed and aged specimens, but 50% of the observers considered the colour match of two specimens to be clinically unacceptable when the colour difference exceeded 10.6. Kinetic studies of thermally and photochemically induced colour change showed a sigmoidal dependence of colour change on the logarithm of exposure time. Because the direction and magnitude of the colour change differed for the two procedures, it would appear that different mechanisms are involved.