Effect of surface treatment on the retention of zirconia crowns to tooth structure after aging.

OBJECTIVE: To evaluate the effect of different surface treatments on the retention between zirconia crowns and tooth structure after in vitro aging. MATERIALS AND METHODS: Human third molars (n = 44) received crown preparations and CAD/CAM zirconia crowns were manufactured. Specimens were divided into two groups: no aging, control (NAC, n = 11) or aging (A, n = 33). NAC were bonded with universal adhesive (UA). Aged specimens were divided into three subgroups (n = 11) according to surface treatment: Control: no abrasion + UA; Alumina: alumina abrasion + UA; Silica: tribochemical silica coating + UA. The crowns were cemented with dual-cure resin cement. Specimens in group A were aged by a combination of mechanical, thermal, and pH cycling. Retention strength values were obtained by tensile tests and results were analyzed by one-way analysis of variance (ANOVA) and Tukey test (P < .05). RESULTS: Aging decreased the retention strength in control specimens (P < .001). Surface treatment improved the retention strength of aged specimens (P < .001), with similar results between alumina and tribochemical silica coating. CONCLUSION: The chemical interaction between the universal bonding system and zirconia's surface was not sufficient to withstand artificial aging. Tribochemical silica coating did not promote additional retention in comparison to alumina blasting. CLINICAL SIGNIFICANCE: The long-term retention of translucent zirconia crowns to tooth structure using phosphate-based materials is improved by means of mechanical surface treatments such as alumina blasting and tribochemical silica coating.

Effectiveness of combined internal-external bleaching for nonvital teeth: case reports.

In general, patients' dissatisfaction with the appearance of their smile is mainly influenced by the color of their teeth. Darkening of a single anterior tooth negatively impacts the appearance of the smile. Tooth bleaching is considered a conservative treatment option for darkened nonvital teeth, and, whenever possible, must be considered the first choice of treatment. This article describes the successful use of the internal-external home bleaching technique in 2 patients, each of whom had a single darkened nonvital tooth. In this technique, the bleaching agent is applied simultaneously to both the internal and external surfaces of the tooth. The bleaching agent of choice is 10% carbamide peroxide. This technique is simple, low cost, and conservative and provides excellent esthetic results.

Clinical evaluation of two in-office dental bleaching agents.

PURPOSE: To evaluate the bleaching efficacy and time required for color stability immediately after dental office bleaching. METHODS: 40 subjects were randomly divided into two groups, according to the bleaching agent used:GHP - 35% hydrogen peroxide gel and GCP - 37% carbamide peroxide gel. The color was measured with a spectrophotometer before and immediately, 24 hours, 72 hours, 7 days and 15 days after the bleaching procedure. The color parameters were evaluated and the ΔE*, ΔL*, Δa* and Δb* values were calculated for each evaluation period. The data was statistically analyzed with Student's T-test, one-way ANOVA and Tukey's post hoc test (P ≤ 0.05). RESULTS: Regarding the ΔE* values, in the assessed periods there were no significant differences between groups (P≥ 0.05). However, the luminosity (ΔL*) decreased considerably in both groups in the first 72 hours (P≤ 0.05), followed by an increase at 15 days (P≤ 0.05) in the hydrogen peroxide group. Regarding the Δb* values, the GHP showed higher negative alterations in the b* axis in the first 24 hours. The 37% carbamide peroxide gel and the 35% hydrogen peroxide gel were effective and there was no reversal of tooth color within 15 days; however a more accentuated bleaching effect was observed immediately after bleaching. CLINICAL SIGNIFICANCE: Rapid bleaching was observed immediately after the in-office bleaching treatment.

Halitosis and Pain Threshold of Peri-Implant Tissues: An Observational Cohort Study.

In this study, we aimed to evaluate the halitosis and pain threshold of the peri-implant soft tissues in individuals rehabilitated with implant-supported prostheses. Forty-eight subjects were divided into four groups (n = 12) according to their prosthetic rehabilitation: single-tooth fixed prosthesis, multi-tooth fixed prosthesis, overdentures, and the Brånemark protocol. Halitosis was measured using a halimeter, whereas the pain threshold was measured using Von Frey monofilaments. Measurements were taken before (t0) and 30 days after (t1) placement of healing caps, and at the time of (t2) and 30 days after (t3) prosthetic placement. Halitosis data were analyzed using the chi-square test and Bonferroni correction (p < 0.05). Two-way ANOVA and Tukey's test (p < 0.05) were used to analyze pain threshold data. We noted an association between halitosis and time for the Brånemark protocol [X2(6) = 18.471; p = 0.005] and overdenture groups [X2(6) = 17.732; p = 0.007], and between halitosis and type of prosthesis only at t0 [X2(6) = 12.894; p = 0.045]. The interaction between time and the type of prosthesis significantly interfered with the mean pain threshold values (p = 0.001). At most time points, the majority of participants in each group had clinically unacceptable halitosis. After 30 days of using the prostheses, the overdenture group had a lower pain threshold compared to the Brånemark protocol group.

Halitosis and Pain Threshold of Peri-Implant Tissues: An Observational Cohort Study

Abstract In this study, we aimed to evaluate the halitosis and pain threshold of the peri-implant soft tissues in individuals rehabilitated with implant-supported prostheses. Forty-eight subjects were divided into four groups (n = 12) according to their prosthetic rehabilitation: single-tooth fixed prosthesis, multi-tooth fixed prosthesis, overdentures, and the Brånemark protocol. Halitosis was measured using a halimeter, whereas the pain threshold was measured using Von Frey monofilaments. Measurements were taken before (t0) and 30 days after (t1) placement of healing caps, and at the time of (t2) and 30 days after (t3) prosthetic placement. Halitosis data were analyzed using the chi-square test and Bonferroni correction (p < 0.05). Two-way ANOVA and Tukey's test (p < 0.05) were used to analyze pain threshold data. We noted an association between halitosis and time for the Brånemark protocol [X2(6) = 18.471; p = 0.005] and overdenture groups [X2(6) = 17.732; p = 0.007], and between halitosis and type of prosthesis only at t0 [X2(6) = 12.894; p = 0.045]. The interaction between time and the type of prosthesis significantly interfered with the mean pain threshold values (p = 0.001). At most time points, the majority of participants in each group had clinically unacceptable halitosis. After 30 days of using the prostheses, the overdenture group had a lower pain threshold compared to the Brånemark protocol group.

Resumo Este estudo teve como objetivo avaliar a halitose e o limiar de dor dos tecidos moles peri-implantares em indivíduos reabilitados com próteses implantossuportadas. Um total de 48 indivíduos foram divididos em quatro grupos (n=12), de acordo com as reabilitações: prótese fixa unitária, prótese fixa multidentária, sobredentadura e protocolo de Brånemark. A halitose foi medida com um halímetro, enquanto o limiar de dor foi medido com monofilamentos de von Frey. As medições foram feitas antes (t0) e 30 dias após (t1) a colocação das tampas de cicatrização e no momento (t2) e 30 dias após (t3) a colocação da prótese. Os dados de halitose foram analisados por meio do teste qui-quadrado e correção de Bonferroni (p < 0,05). ANOVA de duas vias e o teste de Tukey (p < 0,05) foram usados para analisar os dados do limiar de dor. Observou-se associação entre halitose e tempo para o protocolo de Brånemark [X2(6) = 18,471; p = 0,005] e grupos overdenture [X2(6) = 17,732; p = 0,007], e entre halitose e tipo de prótese apenas em t0 [X2(6) = 12,894; p = 0,045]. A interação entre o tempo e o tipo de prótese interferiu significativamente nos valores médios do limiar de dor (p = 0,001). Na maioria dos pontos de tempos, a maioria dos participantes de cada grupo apresentava halitose clinicamente inaceitável. Após 30 dias de uso das próteses, o grupo overdenture apresentou menor limiar de dor em comparação ao grupo do protocolo de Brånemark.

Técnica semidireta: abordagem prática e eficaz para restauração em dentes posteriores / Semidirect technique: practical and effective approach to restoration in posterior teeth

Introdução: Embora as restaurações diretas tenham boas propriedades mecânicas, quando utilizadas sem indicação em cavidades amplas ficam susceptíveis a fratura e ao desgaste. Nesses casos, o ideal é que sejam feitas restaurações indiretas do tipo inlay ou onlay, entretanto o custo da etapa laboratorial das restaurações indiretas limitam a realização dessa técnica. Para tentar minimizar o custo e melhorar as propriedades da técnica direta existe as restaurações semidiretas. Objetivo: Descrever na forma de Um caso clínico a confecção de uma restauração do tipo onlay pela técnica semidireta. Relato de caso: Paciente compareceu a clínica odontológica para substituição de restauração insatisfatória no elemento 46. O tratamento de escolha foi substituição da restauração de resina composta por uma restauração do tipo onlay. A técnica semidireta foi eleita para confecção da restauração, uma vez que agrega as vantagens das técnicas direta e indireta, com um menor custo operacional e tempo de execução. Conclusão: A técnica semidireta é uma opção de tratamento para restaurações em dentes posteriores, com menor custo para o paciente e pode ser seguramente indicada em cavidades amplas (AU).

Introduction: Although direct restorations have good mechanical properties when used without large cavities indicated they are susceptible to fracture and wear. In such cases, the ideal is that indirect restorations of inlay or onlay type are carried out, however the cost of the laboratory stage of indirect restorations limit the realization of this technique. To attempt to minimize the cost and improve the properties of the direct technique exists semidiretas restorations. Objective: To describe the form of a clinical case the making of a restoration type onlay by semidirect technique. Case report: Patient attended the dental clinic for poor restoration replacing the element 46. The treatment of choice was replacement of the composite resin restoration by a restoration of the onlay type. The semi-direct technique was chosen to construct the restoration as it adds the advantages of direct and indirect techniques with a lower cost and execution time. Conclusion: The semidirect technique is a treatment option for restorations in posterior teeth, with less cost to the patient and can be safely displayed in large cavities (AU).