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Aim: Dental professionals are prone to have hearing impairment due to prolonged exposure of noise in dental college. The aim of the study was to assess the hearing ability of dental personnel working in Yenepoya Deemed to be University, Mangaluru, Karnataka, India. Materials and Methods: A cross-sectional exploratory study was conducted on 60 subjects (30 male and 30 female). Audiometric analysis was carried out using pure-tone audiometry (PTA) and otoacoustic emission test (OAE). Statistical Analysis: Data were calculated and analyzed using two-way analysis of variance and Tukey’s honestly significant difference test. Results: No statistically significant difference was observed between hearing loss and its association with age, gender, working experience, mean daily working time, and specialization. PTA results showed a statistically significant hearing loss in the left ear, showing a dip at frequency of 4000 Hz among working experience group of 11–15 years and at 6000 Hz for 21–25 years. Also, a statistically significant hearing loss was observed in the left ear at 6000 and 8000 Hz for the age-group of 51–55 years. OAE results were consistent with PTA findings. Conclusion: Dentists and dental personnel are at a higher risk of noise-induced hearing loss. As the working experience increases, the threshold shift is seen to shift from 4000 to 6000 Hz, which is indicative of sensorineural hearing loss due to noise-induced dental environment.

Aim: Zirconia-based restoration is successfully replacing metal ceramic restorations in posterior areas. Although higher mechanical properties of zirconia, their use in compromised situation is questionable. Hence, there is a need to modify the design which to strengthen the framework. The aim of this in vitro study was to evaluate the influence of lingual collar design on the flexural strength of CAD/CAM-fabricated posterior three-unit zirconia framework. Materials and Methods: A mandibular metallic stainless steel master mold is designed for a three-unit fixed partial denture framework. All CAD-milled 20 samples are divided into two groups based on the design. Group A––with collar (10 samples) and Group B––without collar (10 samples), tested using universal testing machine to calculate the mean fracture load and flexural strength. Statistical Analysis Used: Descriptive statistics and independent sample t test were used to find the difference between the groups, and simple linear regression was used to find the relationship between load and displacement between the groups. Results: The result of the mean flexural strength for Group A was 11328.06 ± 3770MPa and for Group B was 7633.95 ± 3196 MPa; the mean fracture strength observed for Group A was 1274.04 ± 424 MPa and for Group B was 858.80 ± 359 MPa. A statistically significant difference was observed in flexural strength between Groups A and B (P < 0.05). Conclusion: Zirconia framework with connector dimension of 7 mm2 with lingual collar design can be successfully incorporated in compromised situation where an ideal connector dimension of 9 mm2 cannot be placed.