Evaluation of color and translucency of stained and glazed monolithic lithium disilicates and zirconia after toothbrushing with different dentifrices and thermocycling.

PURPOSE: To evaluate changes in color and translucency of stained and glazed monolithic lithium disilicates and zirconia under toothbrushing with conventional or whitening dentifrices followed by thermocycling. MATERIALS AND METHODS: Samples (n=20/material) from CAD/CAM (IPS e.max CAD[EC]) and pressable (IPS e.max Press[EP]) lithium disilicates and 4Y-TZP zirconia (Prettau 4 Anterior[PA]) were prepared and received staining and glazing procedures. Aging was performed by toothbrushing with conventional (n=10) or whitening (n=10) dentifrices, followed by thermocycling, simulating 5, 10, and 15-years. Color coordinates L*, a*, b*, C*, and h° values were assessed with a spectrophotometer at baseline and after each aging period to calculate changes in color (ΔE00), lightness (ΔL*), and translucency (T.P.). Data were analyzed by 3-way repeated measures ANOVAs followed by Sidak's post-hoc tests (α=.05). RESULTS: Comparing the dentifrices, EC and EP produced the greatest ΔE00 after 15-years with the whitening dentifrice (P<.05). Regardless of the dentifrice, PA showed higher ΔE00 than EC after 10-years (P<.05). Comparing the aging periods, EC and PA did not show differences in ΔE00 for both dentifrices (P≥.05). EC and EP produced an increased ΔL* after 15-years in the whitening group (P<.05). In the whitening groups, the ΔL* values of PA differ (P<.005) from those of lithium disilicates. Regardless of the experimental group, the T.P. values followed the inequality PA〈EC〈EP (P<.05). CONCLUSIONS: Overall, the color of stained/glazed monolithic lithium disilicates and zirconia changed under aging with greater effects for whitening dentifrice. The aging did not influence translucency.

Effects of red and infrared laser on post extraction socket repair in rats subjected to alendronate therapy.

This study evaluated the effect of photobiomodulation therapy (PBMT) with a red or infrared laser on the repair of post extraction sockets in rats administered alendronate (ALN). Forty male rats were randomly allocated into four groups: Control Group (CTR): subcutaneous administration of saline solution throughout the experimental period; Alendronate Group (ALN): subcutaneous administration of alendronate during the entire experimental period; Alendronate/Red Laser Group (ALN/RL): administration of ALN and irradiation with a GaAlAs laser (λ 660 nm); and Alendronate/Infrared Laser Group (ALN/IRL): administration of ALN and irradiation with a GaAlAs laser (λ 830 nm). The first lower molars were extracted 60 days after the beginning of the administration of the drugs. The PBMT was applied after tooth extraction (7 sessions with intervals of 48 hours between sessions). Thirty days after tooth extraction, the animals were euthanized. Micro-CT and histometric analysis were performed to assess the bone healing and soft tissue repair of the tooth socket. The ALN group presented with more bone than the CTR; however, most of this bone was necrotic. ALN does not affect the bone microarchitecture. On the other hand, PBMT with IRL enhances the bone density due to the increase in the number and reduction in the spacing of the trabeculae. The amount of vital bone and connective tissue matrix was higher in the ALN/RL and ALN/IRL groups than in the ALN and CTR groups. PBMT enhanced the healing of the post extraction sockets in rats subjected to ALN administration. Furthermore, IRL improved the new bone microarchitecture.

Effects of red and infrared laser on post extraction socket repair in rats subjected to alendronate therapy

Abstract This study evaluated the effect of photobiomodulation therapy (PBMT) with a red or infrared laser on the repair of post extraction sockets in rats administered alendronate (ALN). Forty male rats were randomly allocated into four groups: Control Group (CTR): subcutaneous administration of saline solution throughout the experimental period; Alendronate Group (ALN): subcutaneous administration of alendronate during the entire experimental period; Alendronate/Red Laser Group (ALN/RL): administration of ALN and irradiation with a GaAlAs laser (λ 660 nm); and Alendronate/Infrared Laser Group (ALN/IRL): administration of ALN and irradiation with a GaAlAs laser (λ 830 nm). The first lower molars were extracted 60 days after the beginning of the administration of the drugs. The PBMT was applied after tooth extraction (7 sessions with intervals of 48 hours between sessions). Thirty days after tooth extraction, the animals were euthanized. Micro-CT and histometric analysis were performed to assess the bone healing and soft tissue repair of the tooth socket. The ALN group presented with more bone than the CTR; however, most of this bone was necrotic. ALN does not affect the bone microarchitecture. On the other hand, PBMT with IRL enhances the bone density due to the increase in the number and reduction in the spacing of the trabeculae. The amount of vital bone and connective tissue matrix was higher in the ALN/RL and ALN/IRL groups than in the ALN and CTR groups. PBMT enhanced the healing of the post extraction sockets in rats subjected to ALN administration. Furthermore, IRL improved the new bone microarchitecture.

Strontium ranelate improves post-extraction socket healing in rats submitted to the administration of bisphosphonates.

The aim of this study was to evaluate the effect of strontium ranelate (Sr) on post-extraction socket healing in rats submitted to the administration of bisphosphonates. Sixty rats were submitted to the tooth extraction of the first lower molar after 60 days of the daily administration of saline solution (SS) or alendronate (ALN). Then, the animals were allocated into six groups namely CTR: administration of SS during the whole experiment, ALN: administration of ALN during the whole experiment, ALN/SS: application of SS for 30 days after extraction in animals previously treated with ALN, ALN/Sr: application of Sr for 30 days after extraction in animals previously treated with ALN, ALN/S60: ALN therapy interruption 30 days before the extraction followed by the application of SS for 60 days, and ALN/Sr60: ALN therapy interruption 30 days before the tooth extraction followed by the application of Sr for 60 days. The healing of the post-extraction sockets was evaluated by microCT and histomorphometry. The use of ALN induced partial bone necrosis, inflammatory infiltration, and a delay in soft tissue healing; the use of Sr improved the connective tissue organization. Sr has subtle positive effects on the post-extraction healing in animals submitted to the administration of bisphosphonate.