The aim of this study was to evaluate the effect of erosive/abrasive cycles and two different levels of abrasiveness of dentifrices over enamel and dentin subjected to bleaching. Methods: Enamel and dentin bovine specimens were prepared and submitted to an at-home bleaching treatment using 9.5% hydrogen peroxide gel, which was applied daily (30 min/14 days). Concomitant with bleaching, an erosive cycle was performed using citric acid (0.3%, pH 3.8, 5 mins, 3×/day), followed by immersions in artificial saliva for remineralization (30 mins). Abrasion was done with two (high and low abrasiveness) dentifrices (2×/day, 120 seconds) after the first and third erosive immersion each day. Enamel and dentin softening were assessed by microhardness and erosive tooth wear by optical profilometry. Data were submitted to repeated measures ANOVA, followed by the Tukey's test with a significance level of 5%. Results: For the enamel and considering the erosive-abrasive cycle, significant differences were found between the groups tested, the bleaching, and the abrasiveness of the dentifrice tested; however, the final microhardness values were significantly lower than the initial ones. For dentin, differences were found between the eroded/abrasion and the non-eroded/abrasion groups, with the former presenting lower microhardness values compared with the latter. In addition, bleaching decreased the microhardness values only for the highly abrasive dentifrice, and the final values were lower than for the initial ones for all tested groups. Conclusion: The use of high and low abrasiveness dentifrices during bleaching and concomitant with erosion/abrasion cycles is more harmful to dentin than to enamel. Clinical Relevance: Although bleaching is considered a conservative treatment, it can cause deleterious effects to dental hard tissue. The association of an at-home bleaching technique with erosion and high-or low-abrasive dentifrices harms dentin more than enamel.
BackgroundThe objective of this study was to determine the validity and reliability of the Malay translated Sleep Apnea Quality of Life Index (SAQLI) in patients with obstructive sleep apnea (OSA).MethodsIn this cross sectional study, the Malay version of SAQLI was administered to 82 OSA patients seen at the OSA Clinic, Hospital Universiti Sains Malaysia prior to their treatment. Additionally, the patients were asked to complete the Malay version of Medical Outcomes Study Short Form (SF-36). Twenty-three patients completed the Malay version of SAQLI again after 1–2 weeks to assess its reliability.ResultsInitial factor analysis of the 40-item Malay version of SAQLI resulted in four factors with eigenvalues >1. All items had factor loadings >0.5 but one of the factors was unstable with only two items. However, both items were maintained due to their high communalities and the analysis was repeated with a forced three factor solution. Variance accounted by the three factors was 78.17% with 9–18 items per factor. All items had primary loadings over 0.5 although the loadings were inconsistent with the proposed construct. The Cronbach’s alpha values were very high for all domains, >0.90. The instrument was able to discriminate between patients with mild or moderate and severe OSA. The Malay version of SAQLI correlated positively with the SF-36. The intraclass correlation coefficients for all domains were >0.90.ConclusionsIn light of these preliminary observations, we concluded that the Malay version of SAQLI has a high degree of internal consistency and concurrent validity albeit demonstrating a slightly different construct than the original version. The responsiveness of the questionnaire to changes in health-related quality of life following OSA treatment is yet to be determined.
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