Dental Implant Positioning Accuracy Using a Key or Keyless Static Fully Guided Surgical System: A Prospective Systematic Review and Meta-Analysis.

PURPOSE: To realize a systematic review with prospective meta-analysis aiming to compare the accuracy of static fully guided implant placement depending on the drill key modality (conventional drill key surgery systems versus newer keyless systems) and evaluate the impact of deviations factors. MATERIALS AND METHODS: An electronic systematic search was conducted to identify prospective clinical trials matching inclusion criteria. The variables of interest were coronal global, apical, vertical, and angular deviations. The types of edentulism, and surgical guide support were investigated as deviation factors. Meta-regression (mixed-effect model) was performed. Heterogeneity was assessed using Cochrane's I² test and interpretation thresholds. RESULTS: A total of 1233 implants in 475 patients were analyzed (18 studies included). Coronal global deviation was significantly lower in the keyless group than in the key group (-0.36 mm; 95% confidence interval [CI] -0.62, -0.09; p=0.008). Angulation control of the keyless system was superior to that of the key system (-0.36 degrees; 95% CI -0.75, 0.02; p=0.063). Non-significant differences were found between both groups in apical (p=0.684) and vertical deviations (p=0.958). Significant influence of the type of edentulism (single, partial, total) and surgical guide support (tooth, mucosa, bone) on the overall amount of coronal global, apical, and angular deviations was found (p<0.001). Lowest deviations were found in partial edentulism and tooth-supported surgical guide groups. (p<0.001). CONCLUSION: Keyless static fully guided surgical systems allowed significantly better control of coronal and angular deviations than conventional systems. The types of edentulism and surgical guide support seemed to influence the positioning accuracy.

Failure of Dental Implants and Associated Risk Factors in a University Setting.

PURPOSE: To assess the cumulative failure rate of 4,842 implants comprising six commercial implant brands in a university setting, and to evaluate the influence of different risk factors on the implant failure rate. MATERIALS AND METHODS: A retrospective chart review was conducted in patients receiving dental implants at the School of Dentistry of the International University of Catalonia (Barcelona, Spain) from 2011 to 2018. The inclusion criterion was patients presenting at least one failed implant. RESULTS: The cohort study included 1,510 patients who received a total of 4,842 implants. The cumulative failure rate was 4.9% and 10.8% at the implant and patient levels, respectively. The multiple regression analysis showed that for the same number of implants per patient, variables such as age and sex were not associated with higher implant failure rates. Furthermore, in considering the combination of arch-sector, a statistically significant reduction in failure rate was observed in the posterior maxilla (OR = 0.66, P = .038) and in the posterior mandible (OR = 0.64, P = .037). The results showed all implant brands offering high implant survival rates (> 91%). Nobel Biocare and Straumann implants significantly reduced the risk of implant failure (OR = 0.37, P = .021 and OR = 0.53, P = .024, respectively), while no significant differences were recorded among Klockner (2.8%), MIS (5.4%), Biomet 3i (7.1%), and Astra Tech (8.4%; P ≥ .05). No association was found between implant loss and bone augmentation, time of implant placement, smoking, and history of periodontal disease. CONCLUSION: The implant failure rates obtained in a university setting resulted in overall cumulative rates of 4.9% and 10.8% at the implant and patient levels, respectively, over a 7-year period. Male sex and implants placed in the anterior mandible may be associated with a higher risk of implant failure. Nobel Biocare and Straumann implants seem to positively affect implant survival rate.

Intra-osseous heat generation during implant bed preparation with static navigation: Multi-factor in vitro study.

OBJECTIVES: To compare the intra-osseous temperature reached during bone drilling for dental implant placement using open versus closed static surgical guides and evaluate the influence of bone density, osteotomy drilling depth, and irrigation fluid temperature. MATERIAL AND METHODS: 960 osteotomies were performed with 2 mm pilot drills in 16 solid rigid polyurethane foam blocks. Two main variables were considered: the guide type (open or closed guide) and bone density (hard (D1) or soft (D4). The blocks were divided into four groups according to the type of surgical template and bone density as follows: group one: closed guide and hard bone; group two: open guide and hard bone; group three: closed guide and soft bone; and group four: open guide and soft bone. A combination of different experimental conditions was used, including different bone osteotomy depths (6 or 13 mm) and irrigation fluid temperatures (5°C or 21°C). RESULTS: The highest mean temperature was found in group one (28.29 ± 4.02°C). In the soft bone groups (three and four), the mean maximum temperature decreased compared to groups one and two (dense bone) and was always higher with closed guides (23.38 ± 1.92°C) compared to open guides (21.97 ± 1.22°C) (p < .001). The osteotomy depth and irrigation fluid temperature also significantly influenced the bone temperature (p < .001), especially in hard bone. CONCLUSIONS: The greatest heat generation was observed in high-density bone. The final intra-bone temperature was about 1°C higher with a closed static surgical guide than with an open guide. The heat generation in osteotomy sites was substantially reduced by cooling the irrigation fluid to 5°C.

Influence of bone density, drill diameter, drilling speed, and irrigation on temperature changes during implant osteotomies: an in vitro study.

OBJECTIVE: The aim of this in vitro study was to evaluate the influence of bone type, drill diameter, drilling speed, and irrigation on heat generation while performing osteotomy for dental implants. MATERIALS AND METHODS: Six polyurethane foam blocks simulating type I (dense) and type IV (soft) bone were selected for the study. Each block was subjected to two different experimental conditions for each drill (2- and 3.5-mm diameter): three sub-groups were created: (a) revolutions per minute (50, 100, or 800 rpm) and (b) irrigation (with or without irrigation). RESULTS: In 2-mm drill group, maximum temperature attained was practically identical: 23.73 ± 2.28 °C in the cortical bone and 23.74 ± 2.03 °C in the cancellous bone. For 3.5-mm, groups showed similar results (25.01 ± 1.88 °C for cortical and 24.05 ± 1.94 °C for trabecular bone). In any type of bone, the presence of irrigating fluid helped to control the maximum temperature (p = 0.001). When comparing the 2-mm and 3.5-mm drills, most differences were found at 100 rpm without irrigation (p < 0.001) and at 800 rpm with irrigation (p = 0.001). CONCLUSIONS: Maximum temperature attained was always below the critical threshold that can cause osteonecrosis, showing that both external irrigation with higher drilling speeds and no irrigation with lower speeds were effective methods to avoid excessive heat generation. CLINICAL RELEVANCE: Despite being always below the critical temperature, bone type, drill diameter, drilling speed, and irrigation must be considered temperature-influencing factors during implant osteotomies.

Short implants (< 8 mm) versus longer implants (≥ 8 mm) with lateral sinus floor augmentation in posterior atrophic maxilla: A meta-analysis of RCT`s in humans

BACKGROUND: One of the greatest challenges that dentists face today is to rehabilitate severe atrophied alveolar ridges in partially and completely edentulous patients with implants. Despite the high survival rate of implants placed next to sinus elevation, this technique presents complications that can be avoided by placing short implants, an option that also presents high survival rates. For this reason, the aim of this study is to compare the survival rate, marginal bone loss and complications associated with short implants (< 8 mm) versus longer implants (≥ 8 mm) placed with lateral sinus floor elevation in posterior atrophic maxillae. MATERIAL AND METHODS: A literature search was conducted by two independent reviewers in the PubMed/Medline (National Library of Medicine, Washington, DC) electronic database for articles published from January 2007 to July 2018. Seven qualified articles were selected for the meta-analysis. RESULTS: The test for overall effect did not find statistical significance in the survival rates, overall complications, intra-operative complications, post-operative complications and prosthetic complications. However, the test showed statistically significant differences in biological complications in favor of standard implants, and marginal bone loss between control and test groups in favor of short implants (< 8 mm) was found. CONCLUSIONS: Within the limitations of the present study, prosthetic rehabilitations with short implants (< 8 mm) in posterior maxilla is a reliable treatment option as an alternative to lateral wall sinus floor augmentation

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Advantages and disadvantages of implant navigation surgery. A systematic review.

This review elucidates the advantages and disadvantages of the different implant navigation methods to assist the precise surgical placement of dental implants. Implant navigation surgery can be classified into: dynamic and static navigation, and static navigation can further be divided into full (FG)- and half-guided (HG) implant surgery. The HG implant placement includes the drilling-guided, pilot-drill guided, and the non-computed guided approaches. In dynamic navigation, the bone drilling and the implant placement are completely tracked with a specific software; while the static navigation refers to the use of static surgical templates. The FG associated with flapless surgery and teeth/crown supported guides has demonstrated the highest accuracy, followed by the drilling and pilot HG surgery that may provide comparable results, while the non-computer HG and FH implant placement provide the least accuracy in transmitting the implant positioning from the pre-surgical planning to the patient. Additionally, flapless implant surgery is related to reduced pain, less analgesic consumption, less swelling, shorter chair-time, and reduced risk of hemorrhage while achieving greater patient satisfaction. Nevertheless, other methods such as non-computer HG and FH implant surgery procedures require more surgical experience to overcome their limitations. There is still limited evidence to support dynamic surgery, and further investigations are needed.

Do Penicillin-Allergic Patients Present a Higher Rate of Implant Failure?

PURPOSE: The aim of this clinical study was to determinate if patients allergic to penicillin present a higher incidence of dental implant failure compared with nonallergic patients. MATERIALS AND METHODS: This cross-sectional clinical study analyzed patients rehabilitated with endosseous dental implants between September 2011 and July 2015, at the University Dental Clinic, School of Dentistry, International University of Catalonia (UIC). Prophylactic antibiotic therapy was prescribed for all patients: a single dose of 2 g of amoxicillin taken orally 1 hour before implant surgery for non-penicillin-allergic patients, and 600 mg of clindamycin taken orally 1 hour before the implant surgery for penicillin-allergic patients. Postsurgical antibiotics were prescribed to prevent early implant failures and postoperative infections: amoxicillin 750 mg three times a day for 7 days for nonallergic patients, and in patients with penicillin allergy, 300 mg clindamycin every 6 hours for 7 days. Implant failure was defined as the removal of the implant for any reason and was classified as early or late failure. RESULTS: A total of 1,210 patients' files were analyzed; 8.03% of nonallergic patients and 24.68% of penicillin-allergic patients presented at least one implant failure. In penicillin-allergic patients, 21.05% were classified as late implant failure and 78.95% as early implant failure, with a lack of osseointegration (80%) being the mean reason for an early implant failure. Penicillin-allergic patients demonstrated a higher risk of implant failure with a risk ratio of 3.84 (95% CI) compared with nonallergic patients. CONCLUSION: Penicillin-allergic patients treated with clindamycin presented almost four times the risk of suffering dental implant failure, although other variables such as implant brand, location, and the surgeon's skill might have influenced these results.

Radiological evaluation of maxillary sinus anatomy: A cross-sectional study of 300 patients.

OBJECTIVE: The aim of the present study was to evaluate the principal anatomical characteristics of the maxillary sinus using Cone Beam Computed Tomography (CBCT) in order to facilitate prevention of intra- and post-operative complications. MATERIALS AND METHODS: Three hundred CBCT scans from patients undergoing implant surgery were analysed. The following anatomical structures were evaluated: (1) Residual ridge height (RRH) and width (RRW); (2) Ridge bone density (BD); (3) Maxillary sinus angle (MSA); (4) Maxillary sinus lateral wall thickness (LWT); (5) Schneiderian membrane thickness (MT); (6) Maxillary sinus septa (SS); (7) Posterior superior alveolar artery (PSAA).' RESULTS: Mean patient age was 59.5±13.6. Mean RRH at upper second premolar (2PM) was 8.66±3.95mm, 4.90±2.28mm at first molar (1M), and 5.26±2.13mm at second molar (2M). Mean RRW was 6.72±2.69mm at 2PM, 6.87±2.65mm at 1M and 7.09±2.80mm at 2M. Bone density was 330.93±211.02 Hounsfield Units (HU) at first molar position and MSA was 73.39±15.23°. LWT was 1.95±0.98mm. Mean Schneider Membrane thickness (MT) was 1.82±1.59mm; MT was ≤3mm in 72.9% of patients and >3mm in 27.10%. 20.56% of patients presented bucco-palatal oriented septa with a mean height of 13.11±3.82mm. PSAA was observed in 48.60% and mean distance to the top of the ridge was 13.15±3.71mm, and was mostly observed inside the sinus (53.85%). CONCLUSIONS: CBCT scanning has been shown to be a useful tool for evaluating maxillary sinus anatomical variations. CBCT should be considered the gold standard when evaluating the maxillary sinus area.

Do topical applications of bisphosphonates improve bone formation in oral implantology? A systematic review

Background: The aim of this systematic literature review was to evaluate the feasibility of topical bisphosphonate application for preserving/enhancing alveolar bone in oral implantology. Material and Methods: An electronic search was conducted in the PubMed/Medline, EMBASE, Scopus, Web of knowledge, and Google-Scholar databases for articles dated from January 2000 to December 2016. Two reviewers assessed the quality of the studies independently. Results: A total of 154 abstracts were identified, of which 18 potentially relevant articles were selected; a final total of nine papers were included for analysis. Comparison of the findings of the selected studies was made difficult by the heterogeneity of the articles, all of them animal research papers that showed heterogeneity in the methodologies used and a high or moderate risk of bias. Conclusions: The topical application of bisphosphonate solution would appear to favor new bone formation in alveolar defects, and boosts the regenerative capacities of biomaterials resulting in increased bone density (AU)

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Effect of implant macro-design on primary stability: A prospective clinical study

BACKGROUND: Implant restorations have become a high predictable treatment option. Several caracteristics such as surgical technique and implant design can influence the treatment outcomes. The aim of the present study was to evaluate the influence of implant macro-design on primary stability measured with resonance frequency analysis (RFA) and insertion torque (IT). Material and Mehods: A total of 47 implants divided in two groups: Test group (TI): 22 Tapered MIS(R) Seven implants; Control group (CI): 25 cylindrical Astra(R) Osseospeed implants. All implants were inserted following the manufacturers' standard protocols. Implant primary stability was measured at the moment of implant placement by registering insertion torque values (ITv) and ISQ values by means of Osstell(TM) Mentor (ISQv) (Integration Diagnostic Ltd., Goteborg, Sweden). RESULTS: In the mandible, mean ISQv for tapered implants (TI) was 71.67 ± 5.16 and for cylindrical implants (CI) 57.15 ± 4.83 (p = ISQ was 67.2 ± 4.42 for tapered implants and 49.17 ± 15.30 for cylindrical implants (p = 0.01). Mean insertion torque for TI was 41.5±6.26 Ncm and for CI 39.17 ± 6.34 Ncm (p > 0.05). For tapered implants, no correlation could be found between implant diameter and primary stability. But for cylindrical implants there was a statistically significant correlation between implant diameter and primary stability: ITv (p = 0.03); ISQv (p = stability measured through ISQ and insertion torque values. Moreover, for cylindrical implants positive correlation has been established between implant diameter and primary stability

Effect of implant macro-design on primary stability: A prospective clinical study.

BACKGROUND: Implant restorations have become a high predictable treatment option. Several caracteristics such as surgical technique and implant design can influence the treatment outcomes. The aim of the present study was to evaluate the influence of implant macro-design on primary stability measured with resonance frequency analysis (RFA) and insertion torque (IT). Material and Mehods: A total of 47 implants divided in two groups: Test group (TI): 22 Tapered MIS® Seven implants; Control group (CI): 25 cylindrical Astra® Osseospeed implants. All implants were inserted following the manufacturers' standard protocols. Implant primary stability was measured at the moment of implant placement by registering insertion torque values (ITv) and ISQ values by means of Osstell™ Mentor (ISQv) (Integration Diagnostic Ltd., Goteborg, Sweden). RESULTS: In the mandible, mean ISQv for tapered implants (TI) was 71.67±5.16 and for cylindrical implants (CI) 57.15±4.83 (p=0.01). Mean insertion torque was 46.67±6.85 Ncm for TI and 35.77±6.72 Ncm for CI (p=0.01). In the maxilla, mean ISQ was 67.2±4.42 for tapered implants and 49.17±15.30 for cylindrical implants (p=0.01). Mean insertion torque for TI was 41.5±6.26 Ncm and for CI 39.17±6.34 Ncm (p>0.05). For tapered implants, no correlation could be found between implant diameter and primary stability. But for cylindrical implants there was a statistically significant correlation between implant diameter and primary stability: ITv (p=0.03); ISQv (p=0.04). CONCLUSIONS: Within the limits of the present study, tapered shaped implants achieve higher primary stability measured through ISQ and insertion torque values. Moreover, for cylindrical implants positive correlation has been established between implant diameter and primary stability.

Topical applications of vitamin D on implant surface for bone-to-implant contact enhance: a pilot study in dogs part II.

OBJECTIVE: The aim of this study was to evaluate the effect of topical application of vitamin D over implant surface, placed immediately to the extraction, throughout histological and histomorphometric analysis of peri-implant tissue. MATERIAL AND METHODS: Six American foxhound dogs were used in the study. Mandibular premolar distal roots were extracted. Twenty-four immediate conical C1 implants (MIS, Barlev, Israel) were randomly assigned to the distal site on each site of the mandible in three groups: (Group CI) 12 titanium implants alone; (Test Group DI) 12 titanium implants supplemented with vitamin D. Prior to implanting, test implants (DI) were submerged in vitamin D 10% solution. No treatment was applied at control implants (CI). After 12 weeks, animals were sacrificed. Block sections were obtained and processed for mineralized ground sectioning. Bone-to-implant contact (Total BIC and BIC%), new bone formation (NBF), interthread bone (ITB), and histological linear measurements (HLM) were analyzed. RESULTS: At 12 weeks, all implants were clinically stable and histologically osseointegrated. BIC evaluation showed Total BIC mean and SD values for DI (48.96 ± 2.14), CI (44.56 ± 1.75) (P < 0.05), BIC% DI (43.59 ± 0.98), and CI (42.67 ± 9.26) (P > 0.05). For interthread bone formation, values were as follows: DI (15.21 ± 3.87), CI (14.79 ± 1.45) (P > 0.05), no statistically differences. Regarding peri-implant new bone formation, no statistically differences could be found between the two groups DI (31.87 ± 1.23), CI (27.18 ± 2.38) (P > 0.05). For linear measurements, test group (DI) showed statistically significant less buccal crestal bone loss (CBL) DI (0.37 ± 0.12)*, CI (1.26 ± 0.8) (P < 0.05), and vitamin D implants showed less lingual junctional epithelium DI (1.58 ± 0.43)*, CI (2.18 ± 0.48) (P < 0.05). No differences were observed in the buccal mucosa. CONCLUSION: With the limitation of animal studies, topical application of vitamin D on dental implants could reduce crestal bone loss and increase 10% more bone-to-implant contact at 12-week follow-up period.