Effect of amalgam corrosion products in non-discolored dentin on the bond strength of replaced composite resin.

OBJECTIVES: To evaluate the effect of amalgam corrosion products in non-discolored dentin on the bond strength of replaced composite resin. MATERIALS AND METHODS: One hundred and sixty-one Class I cavities were prepared on extracted premolars and divided into seven groups. Group 1: Light-cured composite; Groups 2, 3, and 4: Amalgam stored in 37°C normal saline for respectively 1, 3, and 6 months and then replaced with composite leaving the cavity walls intact. Groups 5, 6, and 7: Identical to Groups 2, 3, and 4, except the cavity walls were extended 0.5 mm after amalgam removal. Eighteen specimens from each group were selected for shear bond strength testing, while on remaining five samples, elemental microanalysis was conducted. Data were analyzed using Mann-Whitney and Freidman (α = 0.05). RESULTS: There was a significant difference between Groups 1 and 4 and also between Group 1 and Groups 5, 6, and 7. However, Groups 1, 2, and 3 showed no significant difference regarding bond strength. Bond strengths of Group 4 was significantly less than Groups 2 and 3. However, Groups 5, 6, and 7 showed similar bond strength. There was no difference among all groups in terms of metal elements at any storage times.

Inflammatory response of canine gingiva to a chemical retraction agent placed at different time intervals.

BACKGROUND: Exposure of the gingival sulcus while controlling hemorrhage is prerequisites for maximizing treatment outcomes of cervical carious lesions and for obtaining quality impressions for the fabrication of indirect restorations with cervical finish lines. Gingival retraction cords saturated with different chemical agents are widely used for this purpose. The aim of this study was to investigate and compare the inflammatory potential of 15.5%ferric sulfate on connective tissue when placed at different times. MATERIALS AND METHODS: All procedures were performed on three dogs under general anesthesia. Retraction cords saturated with a 15.5% ferric sulfate solution were placed into the gingival sulcus and evaluated after 3 min and 10 min of exposure to the chemical agent. Excisional biopsies of the exposed gingival tissue were then obtained at intervals of 1 h, 24 h, and 7 days. For all specimens, histology evaluation was performed using light microscopy. Data collected from the microscopic images of all tissue specimens were analyzed by using the Wilcoxon Signed Rank and Kruskal-Wallis Tests. P value less than 0.05 was considered as significant. RESULTS: Histopathologic examination of the biopsied gingival tissue revealed that the ferric sulfate solution caused significant tissue changes at the beginning of both the 3-min and 10-min gingival exposure time (P > 0.05). However, the tissue returned to a normal histological appearance by the end of day 7 in all cases (P > 0.05). CONCLUSION: The results of this study revealed that the biologic effects of 15.5% ferric sulfate solution are clinically acceptable and reliable when gingival exposure times of 3 min and 10 min are used for gingival retraction.

Fracture resistance of premolar teeth restored with silorane-based or dimethacrylate-based composite resins.

STATEMENT OF PROBLEM: To restore posterior teeth using low-shrinkage composite to minimize microleakage. PURPOSE: To compare the fracture resistance of mesio-occlusal-distal (MOD) cavity preparations restored with either low-shrinkage composite or with dimethacrylate-based composite in conjunction with cavity liners and without them. The null hypothesis of the study is that there are no differences in either fracture resistance or fracture mode between the silorane group and dimethacrylate groups with and without the use of cavity liners. METHOD AND MATERIALS: Sixty maxillary premolars were divided into six groups of 10. MOD cavities were prepared in four groups: F: posterior composite (Filtek P60); GF: 0.5-mm Glass Ionomer (Fuji LC) + posterior composite; FF: 0.5-mm flowable composite (Filtek Supreme XT) + posterior composite; and S: low-shrinkage composite (Filtek P90). Negative (N) and positive (P) control groups consisted of unrestored and sound teeth, respectively. The specimens were thermocycled and loaded. Data were analyzed using analysis of variance, Tukey, and chi-square tests (α = 0.05). RESULTS: Groups FF (1643.09 ± 187/80 N) and GF (1596.80 ± 163/93 N) (p = 0.06 > 0.05) were statistically identical, although less than group P (1742/33 ± 110/08 N), but still demonstrated greater fracture resistance than the other groups. The fracture resistance of group S (1434/69 ± 107/62 N) was identical to GF and FF (p = 0.06 > 0.05). The fracture resistance of F (1353/19 ± 233/90 N) was less than GF and FF, and statistically identical to S (p = 0.87 > 0.05). CONCLUSION: Silorane-based composite showed a resistance to fracture similar to methacrylate-based composite restorations regardless of whether cavity liners were used. CLINICAL SIGNIFICANCE: The findings of this study support the selection of silorane-based composite for the restoration of maxillary premolars with standardized Class II cavity preparations in order to strengthen the resistance to fracture to the same extent as do dimethacrylate composites using cavity liners or without them.

The effect of photoactivation time and light tip distance on the degree of conversion of light and dual-cured dentin adhesives.

BACKGROUND: The degree of conversion of dental adhesive is an important parameter since poor mechanical properties are related to low percentage of monomer-to-polymer conversion within resin-based materials. OBJECTIVES: To evaluate the influence of polymerization time and light guide distance on the degree of conversion (DC) of three contemporary dental adhesives. MATERIALS AND METHODS: The spectral data of ExciTE DSC, Single Bond ® , and Adper ® Prompt L-Pop were analyzed using FTIR spectroscopy after 20 s, 40 s, and 60 s of photoactivation times. Light tip distances were kept at 1, 3, and 6 mm during the exposures. STATISTICS: Data were analyzed using ANOVA and Tukey's test (α = 0.05). RESULTS: Within groups, greater DC values were found using a tip distance of 1 mm or a 60-s curing time for Single Bond ® (59%) and Adper ® Prompt L-Pop (65%). No statistically significant difference (P > 0.05) was found using either 1 mm or 3 mm tip distances after 20 s, 40 s, and 60 s of light curing time for Single Bond ® . ExciTE ® DSC showed the greatest DC values with light tip distances of 1 mm (90%) and 3 mm (89%), using 60 s of light curing. CONCLUSION: The self-etch adhesive Adper ® Prompt L-Pop could be applied in shallow cavity preparations and must be light cured for at least 40 s. The light-cured total-etch adhesive ExciTE ® DSC could be applied in every restorative scenario if the curing time is extended up to 60 s or if the tip distance is extended up to 3 mm.

The degree of color change, rebound effect and sensitivity of bleached teeth associated with at-home and power bleaching techniques: A randomized clinical trial.

AIM: The purpose of the present randomized clinical trial was to evaluate the color change, rebound effect and sensitivity of at-home bleaching with 15% carbamide peroxide and power bleaching using 38% hydrogen peroxide. MATERIALS AND METHODS: For bleaching techniques, 20 subjects were randomized in a split mouth design (at-home and power bleaching): In maxillary and mandibular anterior teeth (n = 20). Color was recorded before bleaching, immediately after bleaching, at 2 weeks, 1, 3 and 6 month intervals. Tooth sensitivity was recorded using the visual analog scale. The Mann-Whitney test was used to compare both groups regarding bleaching effectiveness (ΔE1), rebound effect (ΔE2) and color difference between the rebounded tooth color and unbleached teeth (ΔE3) while the Wilcoxon compared ΔE within each group. Distribution of sensitivity was evaluated using the Chi-square test (α =0.05). RESULTS: There was no significant difference between groups regarding ΔE1 and ΔE3 (P > 0.05). Even though, ΔE2 showed no significant difference between groups after bleaching as well as at 2 week, 1 month and 3 month follow-up periods (P > 0.05). Although, significant difference was found in ΔE2 (P < 0.05 Mann-Whitney) between two methods after 6 months and a high degree of rebound effect was obtained with power bleaching. Within each group, there was no significant difference between ΔE1 and ΔE3 (P < 0.05 Wilcoxon). The distribution of sensitivity was identical with both techniques (P > 0.05). CONCLUSION: Bleaching techniques resulted in identical tooth whitening and post-operative sensitivity using both techniques, but faster color regression was found with power bleaching even though color regression to the baseline of the teeth in both groups was the same after 6 months.

Energy dispersive x-ray analysis of corrosion products in nondiscolored dentin and a dye-extraction study of Class 2 composite restorations following amalgam removal.

OBJECTIVE: To evaluate the effect of corrosion products on the microleakage of composite placed adjacent to nondiscolored dentin after amalgam removal. METHOD AND MATERIALS: Sixty Class 2 cavities were prepared on extracted premolars, which were divided into four equal groups according to the manner in which they were restored: group 1, light-cured packable composite (Elite LS) to establish a microleakage baseline; group 2, a high-copper amalgam (World Work) previously stored in 37°C normal saline for 6 months to create amalgam corrosion products; group 3, identical to group 2, but the amalgam was later replaced with composite, leaving the cavity walls intact; and group 4, identical to group 3 except the cavity walls were extended 0.5 mm after amalgam removal prior to insertion of the composite. Groups 1, 3, and 4 were kept in a 37°C normal saline for 1 week. Ten specimens from each of these three groups were randomly selected for dye-extraction testing, while dentin elemental microanalysis of five specimens from all four experimental groups was also conducted. Data were analyzed using ANOVA and the Tukey tests (α = .05). RESULTS: Corrosion products were not detected in group 4, and no statistically significant difference (P > .05) in microleakage was found between this group and group 1. The highest dye absorbance was associated with group 3 (P < .05). CONCLUSION: After amalgam removal, a 0.5-mm extension of the cavity walls could improve the dentinal marginal seal to replicate that of an initial composite restoration.

A retrospective clinical evaluation of success rate in endodontic-treated premolars restored with composite resin and fiber reinforced composite posts.

BACKGROUND: The aim of this retrospective study was to assess the survival rate and causes of failure of quartz fiber posts used to restore endodontically treated teeth. MATERIALS AND METHODS: Thirty-eight patients with endodontically treated premolar and anterior teeth that were then restored with a coronoradicular quartz fiber post and extensive composite resin restorations were selected for participation in the study. The age of the restorations ranged from 1 to 6 years. Survival probabilities of the restorations as well as causes of failures were analyzed using the Kaplan-Meier analysis and the Logistic regression (α = 0.05). RESULTS: The overall cumulative survival rate (48.8%) was determined, while the survival probabilities after 1, 2, 4, 5, and 6 years of service were 88.37%, 60.95%, 45.71%, 32.65%, and 0%, respectively. CONCLUSIONS: The survival probability of endodontically treated teeth restored with a quartz fiber post and composite restorations is associated with the dental arch.

Effect of a bleaching agent on the color stability of a microhybrid composite resin / Efeito de um agente de clareamento na estabilidade de cor de uma resina composta micro-híbrida

Objectives: To evaluate the effect of Opalescence™ PF home bleaching gel on the color stability ofAmelogen™ Plus microhybrid composite resin. Material and method: Thirty disks were fabricated fortesting using three different shades (A1, A2 and A3.5) of Amelogen™ Plus composite. Standardized L*a*b*parameters were determined and the specimens were subjected to 15% carbamide peroxide. The L*a*b*parameters were measured again and the color change (ΔE) in the composite disks were calculated. Thedata were analyzed using the One-way ANOVA and Tukey tests. (α = 0.05) Results: In all specimens themean of ΔE was more than 3.3. There was a signifi cant difference between shade A3.5 and A2 and withshade A1, as A1 showed the lowest values of color change with bleached composites being lightened incomparison with the unbleached specimens. The greatest change occurred in the red-green (a*) parameter.Conclusion: 15% carbamide peroxide bleaching gel (Opalescence® PF) caused a clinically detectable colorchange with each of three different shades (A1, A2 and A3.5) of Amelogen™ Plus (ΔE> 3.3) tested. Thegreatest color change occurred with the A3.5 shade and the least change was associated with the A1 shade.

Objetivos: Avaliar o efeito do gel de clareamento doméstico Opalescente® na estabilidade de cor do microcompósitoAmelogen® Plus. Material e método: Parâmetros L*a*b* foram determinados e os espécimes foram sujeitos a peróxidode carbamida a 15%. Os parâmetros L*a*b* foram medidos novamente e a alteração de cor (ΔE) nos discos de compósitofoi calculada. Os dados foram analisados pelos testes One-way ANOVA e Tukey (α = 0.05). Resultados: Emtodos os espécimes o valor médio de ΔE foi maior do que 3.3. Não houve diferença signifi cante entre cores A3,5, e A2A1. A1 mostrou o mais baixo valor, sendo mais claros os compósitos submetidos ao agente clareador em comparaçãoaos espécimes não submetidos. A maior alteração ocorreu no parâmetro vermelho-verde (a*). Conclusão: O gelde peróxido de carbamida a 15% (Opalescente® PF) causou uma alteração de cor clinicamente detectável em cadauma das diferentes cores (A1, A2 e A3,5) do compósito Amelogen® Plus testado. A maior alteração de cor ocorreucom a cor A3.5 e a menor foi associada à cor A1.

Effect of load cycling on nanoleakage of butt joint and beveled occlusal enamel margins in class V composite resin restorations / Efeito do ciclo de carga na nanoinfi ltração de margens de esmalte oclusal com e sem bisel em restaurações classe V

Objectives: This study evaluated the infl uence of mechanical and thermal cycling on the nanoleakageof Class V composite resin restorations with and without enamel beveling. Material and method:Using 60 Class V cavities prepared on the buccal surfaces of human molars, specimens were dividedinto two groups (n = 30) based on the confi gurations of the enamel cavosurface margins. (beveled andnon-beveled) After restoring the cavity preparations with a fl owable composite, half of the specimenswere mechanically load-cycled. The specimens were sealed leaving a 1 mm window around the cervicaland enamel margins. Specimens were placed in a 50% (W/V) silver nitrate solution then immersedin photodeveloping solution and exposed to fl uorescent light for 8h. The teeth were buccolinguallysectioned, gold sputter coated and examined with a SEM to evaluate the nanoleakage values. The datawere analyzed using two-way ANOVA (α = 0.05). Results: Enamel margin confi guration had no significant effect on nanoleakage (p > 0.05). However, the nanoleakage value was signifi cantly higher inthe load-cycled group than in the group not load-cycled (p < 0.05). Conclusion: Since enamel margin confi guration does not affect nanoleakage, there is no need to bevel enamel margins of Class V cavitypreparations for composite restorations.

Objetivos: O presente estudo avaliou a infl uência dos ciclos de carga mecânico e térmico na nanoinfi ltração derestaurações Classe V em resinas compostas, com e sem biselamento do esmalte. Material e método: Os espécimes(60 cavidades Classe V preparadas na superfície vestibular de molares humanos) foram divididos em dois grupos(n = 30) baseados nas confi gurações das margens cavosuperfi ciais do esmalte (biseladas e não biseladas). Após restauraçãodos preparos cavitários com um compósito tipo fl ow, metade dos espécimes foi carregada mecanicamente.Os espécimes foram selados mantendo janela de 1 mm em torno das margens cervical e de esmalte. Os espécimesforam colocados em solução de nitrato de prata (50%), imersos na sequência em solução processadora fotográfi cae expostos à luz fl uorescente por oito horas. Os dentes foram cortados em sentido vestíbulo-lingual, revestidos emouro e observados em microscopia eletrônica para avaliar os valores de nanoinfi ltração. Os dados foram analisadospelo ANOVA (α = 0,05). Resultados: A confi guração das margens do esmalte não teve efeito signifi cante nananoinfi ltração (p > 0,05). Entretanto, os valores da nanoinfi ltração foram signifi cativamente mais altos no grupode carga que no grupo sem carga (p > 0,05). Conclusão: Uma vez que a confi guração da margem do esmalte nãoafeta a nanoinfi ltração, não há necessidade de biselar as margens do esmalte nos preparos de cavidades Classe V emrestaurações de compósitos.

The Health Insurance Portability & Accountability Act and the practice of dentistry in the United States: system security.

This article reviews the issues related to the Health Insurance Portability & Accountability Act (HIPAA) security rule that apply to dental practice. The security rule specifically addresses individually identifiable health information that is transmitted or maintained in electronic media. System security must be applied to the entire technical infrastructure for the practice environment as well as to the work culture on a daily basis and must be thought of as an enterprise asset. Security refers to all of the policies, procedures, tools, and techniques used to assure that privacy and confidentiality are adequately addressed in a healthcare system. HIPAA requires all covered entities that transmit or maintain electronic health information perform, and document, a risk assessment for security and develop a security plan to address major areas of concern. A self-assessment tool is provided in this article.

The Health Insurance Portability and Accountability Act and the practice of dentistry in the United States: electronic transactions.

This article reviews the kinds of electronic transactions required under the Health Insurance Portability & Accountability Act (HIPAA) and relates them to relevant data contained in an electronic oral health record (EOHR). It also outlines the structure of HIPAA transactions using the claim transaction as an example. The relationship of the HIPAA resource management function to those of patient care are discussed. The discussion points out potential future uses of other existing resource management transactions to realize the maximum potential of linking the primary patient care functions to those functions related to managing resources in support of that care. This is needed in all aspects of oral health using the informatics standards activities in which the American Dental Association (ADA) actively participates. The article concludes by providing the dentist a perspective on how to relate these capabilities to his/her individual practice setting.

The Health Insurance Portability and Accountability Act: practice of dentistry in the United States: privacy and confidentiality.

This paper introduces the reader to the Health Insurance Portability and Accountability Act (HIPAA) of 1996 legislation in the context of its relationship to the Electronic Oral Health Record (EOHR). Privacy and confidentiality issues for administrative data are addressed in terms of the broader relationship of such data to the EOHR leaving the HIPAA-defined administrative transactions and security issues for the entire practice for a subsequent presentation. Educational requirements are presented that aid the dentist and the practice staff in understanding the broad and long-term implications of the HIPAA legislation.

The electronic oral health record.

This paper presents the history of the use of the computer for maintaining patient medical care information. An electronic record generated with a computer, which is non-specific for any healthcare specialty, is referred to as the electronic health record. The electronic health record was previously called the computer-based patient record. "Electronic" replaced the earlier term "computer-based" because "electronic" better describes the medium in which the patient record is managed. The electronic health record and its application to dentistry are discussed. The electronic health record is a "database" of patient information that has been entered by any healthcare provider; the electronic oral health record is an "electronic record" of oral health information that has been entered by an oral healthcare provider. The significant differences between the electronic health record and the electronic oral health record are outlined and highlighted. Included is a template describing a procedure to be used by dental personnel during the decision making process of purchasing an electronic oral health record. A brief description of a practice template is also provided. These completed templates can be shared with dental software vendors to clarify their understanding of and to clearly describe the needs of today's dental practice. The challenge of introducing information technology into educational institutions' curricula is identified. Finally, the potential benefit of using electronic technology for managing oral healthcare information is outlined.