Occlusion effects of bioactive glass and hydroxyapatite on dentinal tubules: a systematic review.

OBJECTIVE: Bioactive glass and hydroxyapatite are biocompatible materials used as an adjunct to various dental materials. The present study aimed to evaluate the occlusion effects of bioactive glasses and hydroxyapatite on dental tubules. MATERIALS AND METHODS: We searched the PubMed/Medline, Embase, and Web of Science databases for the relevant records. The methodological quality of the studies was assessed by an accepted quality assessment tool. RESULTS: From the electronic databases, 372 articles were retrieved. After evaluating the records, 35 in vitro studies were included. The studies revealed a low risk of bias. The primary outcomes from bioactive glass studies demonstrated the potential efficacy of both bioactive glass and hydroxyapatite in dentin tubule occlusion compared to the control. CONCLUSION: The current systematic review showed that bioactive glass and hydroxyapatite could effectively occlude the dentinal tubules. Thus, desensitizing agents containing bioactive glass and hydroxyapatite can be used to manage dentin hypersensitivity (DH). However, long-term follow-up clinical trials are required in the future before definitive recommendations can be made. CLINICAL RELEVANCE: This work achieved a satisfactorily systematic review for assessing desensitizing agents containing bioactive glass and hydroxyapatite in dentine hypersensitivity treatments recommended for clinical practice and research.

The comparison of root caries experience between HIV-positive patients and HIV-negative individuals in a selected Iranian population.

OBJECTIVES: Human immunodeficiency virus (HIV) infection is a concerning problem in dentistry and HIV-infected patients may experience root caries due to different risk factors. The aim of this study was to find the prevalence of root caries in a selected Iranian HIV-positive population. METHODS: One hundred and seven IV drug users, based on ELISA and Western Blot test, were divided into two groups: group 1: HIV-positive patients and group 2: HIV-negative individuals. According to the T-CD4(+) cell count, subjects in group 1 were placed in two subgroups: Moderate immunodeficiency (200 mm(-3) < T-CD4(+) cells <500 mm(-3)) and Severe immunodeficiency patients (T-CD4(+) cells <200 mm(-3)). Teeth were examined by an examiner under suitable light to detect any changes in colour, texture or contour. The values of DMFT, DMFS, decayed root surfaces and total decayed surfaces were calculated. Data were analysed by independent t-test and chi-squared test. RESULTS: The mean DMFT, DMFS and decayed root caries in group 1 and 2 had no significant difference. The mean value of total decayed surfaces of HIV+ patients was significantly higher compared with HIV- individuals (P = 0.03). The comparison of all parameters between two subdivisions of group 1 showed no significant difference. CONCLUSIONS: The results indicate that HIV+ patients experienced more dental caries, but not more root caries than healthy ones. Along with decreasing T-CD4(+) cell count, tooth caries' prevalence did not increase. CLINICAL RELEVANCE: Based on our findings, root caries prevalence is almost the same in HIV-positive and negative individuals; however, it is necessary to decrease tooth caries by continual monitoring and periodic dental examination.

Comparison of the effects of two whitening toothpastes on microhardness of the enamel and a microhybride composite resin: an in vitro study.

INTRODUCTION: Whitening toothpastes which have been accepted in populations may affect properties of enamel and restorative materials. The aim of this study was to compare the microhardness of human enamel and Z250 microhybrid composite resin after brushing with two whitening toothpastes. MATERIALS AND METHODS: In this experimental study of enamel specimens, forty five freshly extracted human incisors were prepared and divided into three groups of control enamel (ClE), Crest enamel (CtE) and Aquafresh enamel (AfE). For composite resin specimens, forty five cylindrical-shaped specimens of light-cured Z250 composite were prepared and divided into three groups of control composite (ClC), Crest composite (CtC) and Aquafresh composite (AfC). The control groups were brushed without toothpaste. Crest and Aquafresh group specimens were brushed with Crest and Aquafresh whitening toothpastes, respectively. Vickers microhardness test was performed for all groups. Data were analyzed by One-way ANOVA and Tukey tests. RESULTS: Microhardness values of ClE, CtE, AfE, ClC, CtC and AfC groups were 332.99 ± 26.59, 313.99 ± 20.56, 323.57 ± 27.96, 137.1 ± 3.16, 122.95 ± 3.27 and 130.36 ± 4.8, respectively. One-way ANOVA showed no significant differences among three enamel groups but there was significant difference among composite groups (p<0.01). CONCLUSION: Crest and Aquafresh whitening toothpastes did not affect enamel hardness but reduced the microhardness value of Z-250 composite resin. However, Crest whitening toothpaste decreased the microhardness more than Aquafresh.