Purpose: The aim of this study was to systematically review the available evidence to evaluate the efficacy of vitamin D supplementation or vitamin D depletion on the osseointegration of implants in animals and humans. Methods: The focus questions addressed were “Do vitamin D deficient subjects treated with (dental) implants have an inferior osseointegration than subjects with adequate serum vitamin D level?” and “Do vitamin D supplemented subjects treated with (dental) implants have a superior osseointegration than subjects with adequate serum vitamin D level?” Humans and animals were considered as subjects in this study. Databases were searched from 1969 up to and including March 2021 using different combination of the following terms: “implant”, “bone to implant contact”, “vitamin D” and “osseointegration”. Letters to the editor, historic reviews, commentaries and articles published in languages other than English and German were excluded. The pattern of the present systematic review was customize to primarily summarize the pertinent data. Results: Thirteen experimental studies with animals as subject, two clinical studies and three case reports, with humans as subjects, were included. The amount of inserted titanium implants ranged between 24 and 1740. Results from three animal studies showed that vitamin D deficiency has a negative effect on new bone formation and/or bone to implant contact (BIC). Eight animal studies showed that vitamin D supplementation has a enhancing effect on BIC and/or new bone formation around implants. Furthermore, enhancing the impact of vitamin D supplementation on the osseointegration of implants in subjects with diabetes mellitus, osteoporosis and chronic kidney disease (CKD) were assessed. Studies and case reports involving human subjects showed that patients with a low serum vitamin D level have a higher tendency to exhibit an early dental implant failure. When supplemented with vitamin D the osseointegration was successful in the case reports and a beneficial impact on the changes in the bone level during the osseointegration were determined. Conclusions: Vitamin D deficiency seems to have a negative effect on the osseointegration of implants in animals. The supplementation of vitamin D appears to improve the osseointegration in animals with systemic diseases, such as vitamin D deficiency, diabetes mellitus, osteoporosis, and CKD. Slight evidence supports the hypothesis that humans similarly benefit from vitamin D supplementation in terms of osseointegration. Further investigation is required to maintain these assumptions.

Objectives: This systematic review aimed to investigate and compare the accuracy of free-hand and computer-aided implant surgery (CAIS) approaches in dental implant placement. Material and methods: The PICO question as follows: In patients receiving dental implants, does computer-aided implant surgery superior in accuracy compared to non-computer-aided implant surgery? The primary outcome was angular deviation between the planned and placed position of the implant. An electronic search was made to identify all relevant studies reporting the accuracy of CAIS approaches and freehand for dental implant placement. The data were extracted in the descriptive description, and a meta-analysis of single means was performed to estimate the deviations for each variable using a random-effects model. Results: Out of 1609 initial articles, 55 were selected for data extraction. The mean value of angular, entry, and apex deviations were 7.46°, 1.56 mm, and 2.22 mm for freehand, 5.94°, 1.13 mm, and 1.43 mm for pilot drill-sCAIS, 2.57°, 0.72 mm, 0.88 mm for fully guided-sCAIS (fg-sCAIS), and 3.67°, 1.01 mm, and 1.36 for dynamic CAIS (dCAIS), respectively. Significant differences were found between the freehand and CAIS approaches (p < 0.04). Fg-sCAIS was significantly more accurate than dCAIS systems at the entry (p < 0.001). Conclusions: Compared to the freehand approach, both sCAIS and dCAIS improve implant placement accuracy, with angular deviations ranging from 2° to 6°. Detailed planning is crucial for CAIS, particularly for fg-sCAIS, which demonstrated the highest accuracy than others. As apex deviations of 1 to 2 mm have been observed in CAIS approaches, a 2-mm safety margin should be implemented to minimize surgical risks.

Objectives: This experimental study compared the accuracy of implant insertion using the free‐hand (FH) technique, static computer‐aided surgery (S‐CAIS), or dynamic computer‐assisted surgery (D‐CAIS) and to evaluate the correlation of learning curves between surgeons' experience and surgical time.Materials and Methods: Thirty‐six models were randomly assigned to three groups (FH, n = 12; S‐CAIS, n = 12; D‐CAIS, n = 12). Each model was planned to receive four implants in the maxillary anterior and posterior regions. Twelve participants, six experienced surgeons, and six dental students were included in this study. The primary outcome was the deviation between the planned and final implant placement from each group. Secondary outcomes were each technique's learning curve regarding surgical time.Results: The average deviation at implant platform, apex and gradual deviation with FH technique were 1.31 ± 0.88 mm, 1.75 ± 0.9 mm and 6.67° ± 3.70°, respectively. The average deviation of implant platform, apex and angular in S‐CAIS were 0.67 ± 0.32 mm, 1.00 ± 0.39 and 2.66° ± 1.77°, respectively. The average deviation of implant platform, apex and angular in D‐CAIS were 1.14 ± 0.70 mm, 1.23 ± 0.58 and 3.20° ± 2.16°, respectively. Significant discrepancies at the implant platform, implant apex, and angular deviation were found between all surgical methods (p < 0.016). Learning curves were evident after multiple implant insertions using both freehand and S‐CAIS.Conclusion: The findings indicate that computer‐assisted implant insertion leads to a more precise implant alignment than implants inserted freehand in an experimental set‐up.