Effect of Internal, Office, and Home Bleaching on Shear Bond Strength of Enamel to Porcelain Laminate Veneers

PURPOSE: To compare the effect of office, home, and internal bleaching on the shear bond strength (SBS) of enamel to porcelain laminate veneers. MATERIALS AND METHODS: A total of 36 extracted maxillary central incisors were randomly assigned to four groups: (1) no bleaching (control); (2) office bleaching with 40% hydrogen peroxide (HP); (3) home bleaching with 15% carbamide peroxide; and (4) intracoronal bleaching with sodium perborate (SP) using the walking bleaching technique. All teeth were separately immersed in artificial saliva for 14 days. The enamel surface was then reduced by 0.5 mm, and IPS e.max Press ceramic discs were bonded using a resin cement. After 24 hours, all specimens were thermocycled (5,000 cycles, 5°C to 55°C). The SBS was measured using a universal testing machine, and the failure mode was determined using a stereomicroscope. One-way ANOVA and Tukey honest significant difference tests were used for data analysis (P < .05). RESULTS: A significant difference was noted among the groups (P < .001). The highest SBS was noted in the control group (15.71 ± 5.39 MPa). The mean SBS in the office bleaching group (12.30 ± 4.64 MPa) was almost the same as the control. The lowest mean SBS belonged to the home bleaching group (5.39 ± 3.99 MPa). The mode of failure was adhesive in all four groups. CONCLUSION: If bleaching is intended to be followed by porcelain veneers, the office bleaching technique with 40% HP is recommended. Delaying the bonding procedure for 2 weeks does not appear to be effective with home or intracoronal bleaching.

Bacterial Leakage at Implant-Abutment Interface With Different Intermediate Materials.

A gap exists at the implant-abutment interface in two-piece implants and can serve as a reservoir of bacteria and compromise the health of peri-implant tissue. This study aimed to compare the effect of different intermediate materials on bacterial leakage at the implant-abutment interface. A total of 75 implants were divided into 5 groups (n = 15) based on the material applied at the implant-abutment connection: (1) Atridox, (2) chlorhexidine, (3) Gapseal silicone, (4) saliva, and (5) no material. All the implants were inoculated with 0.1 µL of Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) suspension, and then the respective material was applied. The abutments were connected to the implants, and appropriate torque was applied as recommended by the manufacturer (Implantium, Dentium, Korea, Seoul). Bacterial leakage was determined by evaluating the turbidity of the broth. Bacterial contamination was found in all samples at different times; in groups 1, 2 and 3, contamination was noted after 7, 5, and 6 days, respectively, on average. Contamination occurred averagely after 4 days in groups 4 and 5. The present study showed that Atridox applied at the implant-abutment interface significantly delayed bacterial leakage.

Rehabilitation of a patient with amelogenesis imperfecta and severe open bite: A multidisciplinary approach.

Amelogenesis imperfecta (AI) is typically associated with anterior open bite and a number of other dental problems, which require complex treatments such as orthognathic surgery. This case report describes management of a patient with AI and severe open bite via a multidisciplinary approach.