Effect of prophylactic application of doxycycline at the implant-abutment interface on the outcomes of implant therapy: a split-mouth randomized clinical trial.

OBJECTIVES: Doxycycline hyclate is a controlled-release doxycycline polymer which can locally be applied. This study aimed to assess the effects of the prophylactic application of doxycycline hyclate at the implant-abutment interface on the short-term outcomes of implant therapy. METHOD AND MATERIALS: The present split-mouth randomized clinical trial included 20 subjects who received two mandibular implants bilaterally (40 implants in total). In the test side (n = 20), doxycycline hyclate was injected at the implant-abutment interface at the time of delivery of final prosthesis. No intervention was performed for the control side (n = 20). The marginal bone level on mesial and distal implant surfaces, bleeding on probing, pocket probing depth, and incidence of peri-implant mucositis were recorded at baseline and after 3, 6, and 12 months. RESULTS: Significant differences were found between the test and control sites, all favoring the test group, for marginal bone level changes at mesial and distal implant surfaces as well as for changes in pocket probing depth after 6 and 12 months. Furthermore, the numbers of implants with bleeding on probing and risk of developing peri-implant mucositis were significantly greater in the control group compared to the test group at 3-months, 6-months, and 12-months following baseline. CONCLUSIONS: Within the limitations of this study, it can be concluded that prophylactic application of doxycycline hyclate at the implant-abutment interface results in reduced crestal bone resorption and pocket probing depth levels. In addition, it reduces the risk of developing peri-implant mucositis.

Accuracy of Digital Impression Taking Using Intraoral Scanner versus the Conventional Technique.

Objectives: Intraoral scanners have shown promising results when used as an adjunct or alternative to conventional impression techniques. This study compared the accuracy of digital impression taking using an intraoral scanner versus the conventional technique. Materials and Methods: In this in-vitro experimental study, a typodont molar tooth was prepared as the standard model and scanned by TRIOS intraoral scanner. Ten digital impressions were fabricated as such and intraoral scans were sent to the manufacturers. In the conventional method, using addition silicone impression material, a stone die was fabricated. Using a computer-aided design/computer-aided manufacturing scanner, the die was scanned, and the data were transferred to the software. After the fabrication of frameworks, the replica technique was used. The replicas' thickness (indicative of the gap between the framework and the model and the accuracy of impression taking) was 12 points. The data were analyzed using student's t-test. Results: The mean thickness of replicas (gap between the internal surface of frameworks and the standard model) at the three points in the buccal, lingual, mesial, and distal sections in the digital impression technique was lower than that in the conventional technique (P<0.0001). In other words, the accuracy of impressions taken by the digital method was significantly higher than those taken by the conventional method. Conclusion: Intraoral digital scanner had significantly higher accuracy than the conventional method in all points. Thus, the digital method can be reliably used as an adjunct or alternative to the conventional method to increase the accuracy of impression taking.