Four chemical methods of porcelain conditioning and their influence over bond strength and surface integrity.

Objective: To assess four different chemical surface conditioning methods for ceramic material before bracket bonding, and their impact on shear bond strength and surface integrity at debonding.

Methods: Four experimental groups (n = 13) were set up according to the ceramic conditioning method: G1 = 37% phosphoric acid etching followed by silane application; G2 = 37% liquid phosphoric acid etching, no rinsing, followed by silane application; G3 = 10% hydrofluoric acid etching alone; and G4 = 10% hydrofluoric acid etching followed by silane application. After surface conditioning, metal brackets were bonded to porcelain by means of the Transbond XP system (3M Unitek).

Oxygen Saturation in Dental Pulp of Permanent Teeth: Difference between Children/Adolescents and Adults.

Introduction: The objective of this study was to use pulse oximetry to measure oxygen saturation in permanent maxillary central incisors with normal pulp in 2 different age groups: children/adolescents and adults.

Methods: Blood oxygen saturation levels were measured using a pulse oximeter in 110 maxillary central incisors of 57 individuals, in 1 of 2 possible age bands, as follows: 28 children/adolescents (7-13 years old) and 29 adults (22-36 years old). The following factors were also analyzed: (1) heart rate (beats/min); (2) oxygen saturation rate measured at the patient's index finger, also using a pulse oximeter; (3) tooth crown dimensions; and (4) the time taken by the oximeter to provide a reading.