The Effect of Dental Adhesive on Final Color Match of Direct Laminate Veneer (DLV): In Vitro Study.

AIM: To evaluate the influence of dental adhesive on the color match of direct laminate veneer. MATERIALS AND METHOD: Specimens were prepared in the form of discs. B1 nano-filled composite Filtek Z-350 XT (3M-ESPE) and single-bond universal adhesive were used. Twenty discs of each test group with a diameter of 10 ± 0.1 mm and thickness of 0.7 ± 0.1 mm were prepared. The specimens were divided into three groups: control group that has composite material only (C), a group that has adhesive with composite material (AC), and a group that has adhesive with composite and re-bonding technique (ACR). The samples were placed in viewing port for color measurement. Spectrophotometer was used in this study. Descriptive statistical analysis was performed for the CIE L*, a*, and b* values. Statistical software IBM SPSS 16.0 was used for analyzing the data, with a significance level of 0.05 (p < 0.05). RESULTS: In this study, both groups where bonding agent was applied had significant change in color of the samples (p < 0.05). AC and ACR showed a change along the "a" coordinate and the "b" coordinate with using adhesive and re-bonding technique. There were significant differences when comparing the values of a* and b* of the control group C with AC group and ACR on using adhesive and re-bonding technique. ACR specimens presented the lowest "L" value. CONCLUSION: Within the limitations of this study, despite the fact that the change of color is not extensive, the dental adhesive changes the color of direct composite restoration in a way that may warrant caution. Additional studies are essential to substantiate the findings of this study. CLINICAL SIGNIFICANCE: Dental adhesive play an important role in changing the color of direct composite restoration.

Hearing loss and its association with occupational noise exposure among Saudi dentists: a cross-sectional study.

OBJECTIVES/AIMS: Dental practitioners are prone to hearing loss due to noise exposure encountered in dental clinics. The aim of this study was to determine whether the persistent high-frequency sounds produced by the dental equipment could cause hearing decrement among the Saudi dental practitioners. MATERIALS AND METHODS: This cross-sectional study included 38 randomly selected Saudi dentists from different specialties who were exposed to noise during working hours and 38 individuals as a control group. The participants underwent four audiometric tests that included an otoscopic examination, tympanometry, pure tone audiometry and the distortion product otoacoustic emissions (DPOAE) test. RESULTS: The data revealed that ~15.8% of the dentists and 2.6% of the control group had some hearing loss. No significant difference was found between the two groups in the pure tone audiometry test; however, qualitative analysis revealed a higher percentage of hearing loss among the dentists' group as compared with their control counterparts. A statistically significant difference was found in DPOAEs between the two groups in the left ear (P=0.002), and between the right and left ears (P=0.005). DISCUSSION: In the present cross-sectional study, the prevalence of hearing loss among dentists as assessed with the pure tone audiometry test was 15.8%. Which was in accordance with a previous study performed by Khaimook et al., which revealed the prevalence of hearing loss in dental personnel to be 17.7%; however, no significant differences were observed compared to the control group in both studies. The otoacoustic emission test in the left ear exhibited significant changes. These changes could have been due to the presence and continuity of the sounds produced by high- and low-velocity suction devices on the left side of the dental unit knowing that 97% of the dentists are right handed. CONCLUSION: Evidence suggests that noise from dental clinics can cause hearing problems, which had a greater effect on the left ear than the right; however, these problems are not severe in nature. Noise-induced hearing loss was more prevalent among the dentists than the control group.