This review focuses on the risk of transmission of HIV in dental practice in developed and developing countries; and as a result of oral sex, perinatal transmission and breast feeding. Postexposure prophylaxis (PEP) and practical measures to control cross-infection with TB are also discussed. There are few data from resource-poor countries where prevalence of HIV and risk of infection are higher--issues that deserve priority. Available information indicates that the risk of HIV transmission in the dental office is very low. Transmission of HIV from three healthcare workers to patients has been confirmed, including a dentist who infected six patients. There are >300 reports (102 confirmed) of occupational transmission to healthcare workers, including nine dental workers (unconfirmed). Exposure to HIV has been reported by 0.5% dentists/year. The risk of HIV infection after percutaneous exposure (0.3%) can be reduced by 81% with zidovudine PEP. However, risk assessment is required to assess the need and appropriate regimen. The risk of HIV transmission associated with orogenital sex exists, but is considered extremely low: barrier protection is recommended. Conversely, the proportion of babies who acquire HIV from untreated HIV-seropositive mothers is 15-25% in developed countries and 25-45% in developing countries. The frequency of HIV transmission attributable to breastfeeding is 16%. Airborne transmission of TB can be avoided by the prompt referral of known/suspected cases of active TB for chemotherapy, deferral of elective procedures until patients are not infectious, and the use of appropriate standard/isolation precautions including adequate ventilation of treatment areas.

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An unerupted maxillary third molar tooth from a 57‐year‐old Caucasian male, which showed radiographic evidence of crown resorption, but was otherwise symptomless, was examined post‐extraction by light and scanning electron microscopy. (SEM) Appearances of the residual dental tissues were consistent with a diagnosis of an invading external resorption with formation of pulpal granulation tissue, dentinal resorption and some dentinal metaplasia. SEM of crown fragments indicated a generally uniform pattern of enamel resorption, for which the ameloblasts rather than multinucleate cells were implicated. By extrapolation of the activity of the former cells during the late stages of amelogenesis and tooth eruption, it is suggested that resorptive activity of and by enamel epithelium may explain not only the coronal origin of this type of idiopathic resorption, (which is otherwise unexplained), but also its progress into the pulp and the pulp reactions.