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OBJECTIVE The aim of this study was to evaluate the effect of guided sleeve height, drilling distance, and guided key height on accuracy of static Computer-Assisted Implant Surgery (sCAIS). MATERIALS AND METHODS Pre and post-operative positions of implants placed in duplicate dental models were compared and recorded after placement of implants according to a standardized treatment planning and execution sCAIS protocol. Guided sleeve heights: 2 mm, 4 mm, 6 mm and guided key heights: 1 mm and 3 mm were equally randomized in six test groups with varying implant lengths (10-16 mm) and surgical drilling protocols. The mean crestal and apical three-dimensional (3D) deviation, as well as the angular deviation were calculated for each group. Data was analyzed using multivariate analysis anova. P values less than .05 were considered statistically significant. All P values of post-hoc tests were corrected for multiple testing using Bonferroni-Holm's adjustment method. RESULTS 3D implant positioning accuracy was not significantly affected by the difference in sleeve height alone or by the implant length alone (P > .05). However, 3D and angular deviation values became significantly higher as the total drilling distance below the guided sleeve increased and significantly became lower as the guided key height above the sleeve increased. 18 mm drilling distance resulted in a significantly higher deviation, when compared to 14 mm or 16 mm drilling distances, irrespective of sleeve height or implant length (P

Over the past decade, the use of digital technology in implant treatment planning and static computer-assisted implant surgery (sCAIS) has revolutionized the planning and execution of guided implant surgeries. However, the predictability of achieving a high degree of accuracy when using a digital workflow and sCAIS has been a subject of debate. For sCAIS procedures to transition from clinical success in individual cases to a broadly applicable procedure, a better understanding and control of variables that affect their accuracy is essential. Recently, a research team in the Department of Oral Surgery and Stomatology at the University of Bern launched a series of in-vitro investigations to further analyze the impact and magnitude of potential variables involved in the digital treatment planning of sCAIS procedures that can have a significant effect on the accuracy of sCAIS. This article presents the rationale and summary of their findings.

OBJECTIVE The aim of this study was to evaluate the effect of three different macrodesigns and two different insertion devices on the accuracy of static computer-assisted implant surgery (sCAIS). MATERIALS AND METHODS Ninety implant replicas with three different macrodesigns: Soft tissue level (TL), bone level (BL), and bone level tapered (BLT) were placed in 30 dental models with two implant insertion devices: Guided adapter and guided screwed-in mount. Preoperative and postoperative positions of implants were compared and the mean angular deviation, crestal, and apical three-dimensional (3D) deviation were calculated for each implant macrodesign and each insertion device. Data were analyzed using analysis of variance, post hoc t-tests and Bonferroni-Holm's adjustment method. P values less than .05 were considered statistically significant. RESULTS BLT implants had lower mean 3D deviation values at the crest and the apex when compared with 3D deviations with BL and TL implants (P .05). Considering the insertion device method, no significant differences were noted between insertion devices irrespective of the deviation analyzed. CONCLUSION The macrodesign of dental implants may have an influence on the accuracy of sCAIS, with tapered designs offering slightly better positional accuracy than parallel-walled macrodesigns independent on the method of insertion used.

OBJECTIVES To evaluate the patient population over a 3-year period and to compare it to observations of the population at the same clinic over a period of 15 years. MATERIAL AND METHODS Records of patients receiving dental implants in the Department of Oral Surgery and Stomatology, University of Bern, between January 2014 and December 2016 were analyzed and then compared with data from patients treated between 2002 and 2004 and between 2008 and 2010. Patients were analyzed for demographics and for indications for therapy, as well as for presence or absence and type of complications. Inserted implants were analyzed for type, length, and diameter, as well as for the number and type of associated tissue regeneration procedures. RESULTS Analysis revealed a continuous linear increase in the average age of patients seeking implant treatment. The most common indication for implant therapy was a single-tooth gap (STG) (50.5%), followed by distal extension situations (22.3%) and extended edentulous gaps (20.5%). A total of 60.8% of implants placed needed some type of bone augmentation, and 83.5% of implants placed in the anterior maxilla required simultaneous augmentation. Staged guided bone regeneration (GBR) was only necessary in 7% of the cases. Implant failure rates remained low at 0.6%, with postoperative hematomas being the most common postoperative complication (13.4%). CONCLUSIONS The rising demand for dental implants continues as the patient population ages. Single-tooth gaps remained consistently the most common indication for implant therapy in recent years. Proper case selection and evidence-based surgical protocols are essential for high success rates.

OBJECTIVE To investigate the effect of surgical guide support and implant site location on the accuracy of static Computer-Assisted Implant Surgery (sCAIS) in partially edentulous patients. MATERIALS AND METHODS 375 replica implants were inserted in 85 study models. Surgical implant placement was done using static 3D printed surgical guides, which were designed to be supported either by all the teeth present in the model (full arch), or by 4-teeth), 3-teeth or 2-teeth. Each study model included three single-tooth gap (STG) situations; one extraction socket site and two implants placed in a distal extension situation. Preplanned and postoperative implant positions were compared using the treatment-evaluation tool in digital software. 3-dimensional and angular deviations were measured. Statistical analysis was done using ANOVA, and pairwise t tests and Bonferroni-Holm's adjustment were applied as a post hoc test. RESULTS Accuracy of surgical guides used in sCAIS was significantly affected by the number and type of teeth used for its support. Guides supported by 4 teeth were not significantly different from accuracy of full-arch-supported guides (p > .05). Guide support by posterior teeth was associated with an increased level of accuracy, when compared to anterior teeth guide support. Implants placed in extraction sockets were associated with significantly higher 3D and angular deviation values (p

OBJECTIVES Working Group 5 was assigned the task to review the current knowledge in the area of digital technologies. Focused questions on accuracy of linear measurements when using CBCT, digital vs. conventional implant planning, using digital vs. conventional impressions and assessing the accuracy of static computer-aided implant surgery (s-CAIS) and patient-related outcome measurements when using s-CAIS were addressed. MATERIALS AND METHODS The literature was systematically searched, and in total, 232 articles were selected and critically reviewed following PRISMA guidelines. Four systematic reviews were produced in the four subject areas and amply discussed in the group. After emendation, they were presented to the plenary where after further modification, they were accepted. RESULTS Static computer-aided surgery (s-CAIS), in terms of pain & discomfort, economics and intraoperative complications, is beneficial compared with conventional implant surgery. When using s-CAIS in partially edentulous cases, a higher level of accuracy can be achieved when compared to fully edentulous cases. When using an intraoral scanner in edentulous cases, the results are dependent on the protocol that has been followed. The accuracy of measurements on CBCT scans is software dependent. CONCLUSIONS Because the precision intraoral scans and of measurements on CBCT scans and is not high enough to allow for the required accuracy, s-CAIS should be considered as an additional tool for comprehensive diagnosis, treatment planning, and surgical procedures. Flapless s-CAIS can lead to implant placement outside of the zone of keratinized mucosa and thus must be executed with utmost care.