Investigation of the prevalence, clinical features, and risk factors of dentin hypersensitivity in a selected Brazilian population.

OBJECTIVES: To evaluate the prevalence, clinical features, and risk factors of dentin hypersensitivity (DH) in a Brazilian population. MATERIALS AND METHODS: 300 patients at the Dentistry Clinic of the University of São Paulo participated in this study. The subjects completed a questionnaire regarding their personal information, the presence of DH, and some of its risk factors. Following completion of the questionnaire, a clinical examination was undertaken. To confirm the presence of DH, the subjects were evaluated with the use of a probe and cold air from a triple syringe. Statistical analysis was performed with the chi-square test and odds ratio, with the critical level p <0.05. RESULTS: The prevalence of DH was 46%. Females presented a higher prevalence than males (p <0.05). The left posterior region was affected by DH the most (maxilla = 41% and mandible = 36%). Cold was reported as the most common pain-inducing stimulus (88%). The pain was described as "discomfort" by 51% of the subjects with DH. Toothbrushing four times a day (p <0.05), toothbrushing with excessive force (p <0.05), bruxism (p <0.05), and gastroesophageal reflux (p <0.05) were strongly correlated with DH. CONCLUSIONS: The prevalence of DH was particularly high. The risk factors for DH were gender (female), toothbrushing four times a day, toothbrushing with excessive force, bruxism, and gastroesophageal reflux. CLINICAL RELEVANCE: DH was a common finding in this population suggesting that preventive measures considering its risk factors must be implemented in order to reduce or control the symptoms.

Influence of aluminum oxide sandblasting associated with Nd:YAG or Er:YAG lasers on shear bond strength of a feldspathic ceramic to resin cements.

OBJECTIVE: This in vitro study evaluated the influence of the surface pretreatment of a feldspathic ceramic on the shear bond strength of two different resin cements. BACKGROUND DATA: Although several conventional surface treatments have been used on feldspathic ceramic, few studies have investigated the effects of an alternative surface treatment, the association of aluminum oxide sandblasting with Nd:YAG and Er: YAG lasers. METHODS: Sixty samples made of a feldspathic ceramic were divided into three groups (n = 20) and treated with (1) controlled-air abrasion with Al(2)O(3) + 10% hydrofluoric acid (HF), (2) Al(2)O(3) + Er:YAG laser, and (3) Al(2)O(3) +Nd:YAG laser. Afterward, silane (Dentsply) was applied on each treated surface. Each of the three main groups was divided into two subgroups (n = 10), where a different resin cement was employed for each subgroup. It was built a cylinder with resin cement (RelyX Arc) in subgroup (A) and with self-adhesive cement (RelyX U100) in subgroup (B). After 24 h at 37 degrees C, the prepared specimens were submitted to shear bond strength test and stereoscopic evaluation to determine the type of failure. RESULTS: Bond strength mean values were not statistically significant for the surface treatment methods or resin cements. CONCLUSION: The null surface treatment proposed with aluminum oxide sandblasting associated with the Er:YAG or Nd:YAG laser and using cementation with self-adhesive cement can be an alternative bonding technique for feldspathic ceramic, since it was as effective as the conventional treatment with aluminum oxide sandblasting and hydrofluoric acid using the conventional resin cement.