Accuracy of surgical templates with and without metallic sleeves in case of partial arch restorations: A systematic review.

INTRODUCTION: The aim of the present systematic review was to evaluate whether there were any differences in the three-dimensional accuracy and the implant survival rate of implants placed using computer-assisted planning and surgical templates with or without metallic sleeves. SOURCES: This systematic review was written according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and registered to the PROSPERO (International prospective register of systematic reviews) database. STUDY SELECTION: PICOS (population, intervention, control, outcomes, and studies) question was assessed, too. Search strategy encompassed the online (MedLine) literature from 1990 up to December 2020 published in English, and evaluating the accuracy of surgical templates with and without metallic sleeves in partial or complete patients. Only in vivo, randomized controlled trial and observational studies were included. Quality assessment of selected full text articles was performed according to the CONSORT (CONsolidated Standards of Reporting Trials) and STROBE (Strengthening the Reporting of Observational studies in Epidemiology) statement guidelines, respectively. For data analysis, the three-dimensional accuracy and the overall implant survival rate was calculated and compared between implants placed using surgical templates with or without metallic sleeves. DATA: A total of 12 articles fulfilled the inclusion/exclusion criteria. Data from 264 patients with 614 implants were subjected to quality assessment (templates with metallic sleeves: 279 implants and 136 patients; templates without metallic sleeves: 335 implants and 128 patients). In all the three deviation parameters (angular, vertical, and horizontal), the differences in average accuracy were noticed (angular 2.33° ± 2.01° versus 3.09° ± 1.65°, vertical: 0.62 ± 0.36 [mm] versus 0.95 ± 0.42 [mm]; and horizontal: 0.62 ± 0.41 [mm] and 1.11 ± 0.57 [mm]. No differences was found regarding overall implant survival rate (0.4891). CONCLUSIONS: With the limitations of the present study, the surgical templates without metallic sleeves demonstrated high level of accuracy in all the three-dimensional measurements, when used to rehabilitate partially edentulous patients. Further randomized controlled trials, reporting according to the CONSORT guidelines are needed to confirm that the differences in accuracy depended on the type of used templates.

Clinical evaluation of a novel dental implant system as single implants under immediate loading conditions - 4-month post-loading results from a multicentre randomised controlled trial.

PURPOSE: To evaluate the safety and clinical effectiveness of a novel dental implant system (GENESIS Implant System, Keystone Dental, Massachusetts, USA) using another dental implant system by the same manufacturer as a control (PRIMA Implant System, Keystone Dental). MATERIALS AND METHODS: A total of 53 patients requiring at least two single crowns had their sites randomised according to a split-mouth design to receive both implant systems at six centres. If implants could be placed with a torque superior to 40 Ncm they were to be loaded immediately with provisional crowns, otherwise after 3 months of submerged healing. Provisional crowns were replaced by definitive crowns 4 months after initial loading, when the follow-up period for the initial part of this study was completed. Outcome measures were crown/implant failures, complications, pink esthetic score (PES), peri-implant marginal bone level changes, plaque score, marginal bleeding, patients and preference of the clinician. RESULTS: In total 53 PRIMA and 53 GENESIS implants were placed. Three patients dropped out but all of the remaining patients were followed up to 4-months post-loading. No PRIMA implant failed whereas four GENESIS implants failed. Only two complications were reported for PRIMA implants. There were no statistically significant differences for crown/implant failures (difference in proportions = 0.080; P (McNemar test) = 0.125) and complications (difference in proportions = -0.04; P (McNemar test) = 0.500) between the implant systems. There were no differences at 4-months post-loading for plaque (difference = -0.54, 95% CI: -3.01 to 1.93; P (Paired t-test) = 0.660), marginal bleeding (difference = -3.8, 95% CI: -7.63 to 0.019; P (Paired t-test) = 0.051), PES (difference = 0.47, 95% CI: -0.56 to 1.50; P (Paired t-test) = 0.365) and marginal bone level changes (difference in mm = -0.04, 95% CI: -0.33 to 0.26; P (Paired t-test) = 0.795). The majority of the patients (46) had no preference regarding the two implant systems evaluated. Three operators preferred GENESIS implants, two had no preference and one preferred GENESIS in medium and soft bone and PRIMA in hard bone. CONCLUSIONS: No statistically significant differences were observed between the systems' implant types, although four GENESIS implants failed versus none of the PRIMA type. Longer follow-ups of wider patient populations are needed to better understand whether there is an effective advantage with one of the two implant designs. Conflict-of-interest statement: This research project was originally funded by Keystone Italia, Dental spa (Verona, Italy), the manufacturer of the implants evaluated in this investigation. However, when Keystone Italia received the data of the present manuscript, they refused to honour the financial agreement for the present publication. Therefore, no further follow-ups of this trial will be considered. A legal action was initiated against Keystone Italia. The data belonged to the authors and by no means was the manufacturer allowed to interfere with the conduct of the trial or the publication of the results.

Early implant loading in the atrophic posterior maxilla: 1-stage lateral versus crestal sinus lift and 8 mm hydroxyapatite-coated implants. A 5-year randomised controlled trial.

PURPOSE: To evaluate the efficacy of long implants (10-16 mm) inserted in maxillary sinuses augmented according to a lateral approach versus short (8 mm) implants placed in crestally augmented sinuses, early loaded after 45 days. MATERIALS AND METHODS: Forty partially or fully edentulous patients having 3 to 6 mm of residual crestal height and at least 4 mm in thickness below the maxillary sinuses were randomised according to a parallel group design to receive either one to three 10 to 16 mm-long hydroxyapatite-coated implants (20 patients) after lateral sinus lifting with 50% an organic bovine (Bio-Oss) and 50% autogenous bone, or 8 mm implants (20 patients) after crestal sinus lifting with autogenous bone. Implants were submerged and left healing for 45 days before loading the implants. Within 1 week after abutment connection, implants were loaded with screw-retained full acrylic provisional prostheses. Definitive metal-ceramic prostheses were provisionally cemented 45 days after abutment connection. Outcome measures were prosthesis and implant failures, any complications, and radiographic periimplant marginal bone level changes. In addition, the stability of individual implants was assessed with Osstell and Periotest at abutment connection (baseline), and at 1 and 5 years after loading by blinded outcome assessors. All patients were followed up to 5 years after loading. RESULTS: One patient dropped out (death) from the longer implant group. One implant failed in the short implant group versus 5 implants in 3 patients of the longer implant group. The difference was not statistically significant. Four complications occurred in 4 patients of the short implant group versus 8 complications in 7 patients of the long implant group, the difference being not statistically significantly different. However, the 2 major postoperative complications occurred in the longer implant group: 1 abscess, and 1 sinusitis that led to the complete failure of the treatment in 2 patients (4 implants lost). A total of 0.72 mm of peri-implant marginal bone was lost after 5 years at long implants and 0.41 mm at short implants, the difference between the two groups was statistically significant (P = 0.028). Osstell values increased and Periotest decreased over time and there were no differences between groups at any time points. CONCLUSIONS: In atrophic maxillary sinuses with a residual bone height of 3 to 6 mm, 8 mm short implants placed in a simultaneously crestally lifted sinus might be a preferable choice than a 1-stage lateral sinus lift for placing longer implants since they appear to be associated with less morbidity. If these implants are placed with an insertion torque >35 Ncm and are joined together under the same prosthesis, they can be early loaded at 6 weeks.