Risk Factors for Dental Implant Failure in Private Practice: A Multicenter Survival Analysis.

PURPOSE: The objective of this study was to quantify the probability of implant failure over time from intrinsic patient factors using a population of patients from multiple private practices. MATERIALS AND METHODS: The records for this retrospective, multicenter cohort study were randomly selected from eight private practices. The primary outcome variable was time to event (implant failure or last known follow-up). The included independent variables were age, sex, diabetes status, smoking status, and arch location. Analyses were performed with Cox proportional hazards on three models: univariate, full multivariate, and systemic factor multivariate. The probability of implant survival at 1, 5, and 10 years was calculated using univariate time-to-event modeling on log-normal distribution with 95% CIs and Cox proportional hazard tests for significance. The Kaplan-Meier survival curve was calculated for patients < 71 years of age. RESULTS: Eight hundred thirty-five implant-level records from 378 patients were collected for analyses. The mean patient age was 60 years, and 48% were men, 15% reported a history of smoking, and 16% reported having diabetes. The follow-up time was as long as 17 years, with a mean of 23.1 months, and a median of 7 months. The hazard ratio (HR) for implant failure due to sex (HR = 1.18; 95% CI: 0.52 to 2.66), smoking (HR = 1.30; 95% CI: 0.49 to 3.46), diabetes (HR = 1.17; 95% CI: 0.35 to 3.86), and arch location (HR = 2.13 to 3.39) failed to reach the threshold within any Cox proportional hazards model (P > .05). CONCLUSION: The implant survival probability for patients ≤ 70 years of age is 86.4% at 10 years in the course of routine private practice by experienced providers. Cautious interpretation of these results is critical, as the effects of known systemic risk factors are likely tempered by effective modifications in clinical decisions and protocols with short- and long-term follow-up maintenance.

Risk factors in bone augmentation procedures.

Bone augmentation is an extremely common procedure in implant dentistry today because of significant advancements with reactive biomaterials, a better understanding of the mechanism of action that is found with growth factors contained in platelets, and improvements in surgical techniques. The expectation is for the surgeon to place the dental implant in the position that best serves the requirements of the prosthetic restorations. With the increasing demands that patients have for ideal prosthetic results, surgeons are expected to predictably augment both hard and soft tissues to provide the anticipated esthetic and functional outcomes. Bone grafting can be performed before, during, and after the implant placement; however, these augmentation procedures come with increased cost, the risk of complications such as infection or failure, and lengthening of the total treatment time. In addition, a plethora of grafting materials are available commercially, where they are often inadequately studied, or there is minimal information regarding their predictability or long-term success, or ability to support dental implants. It is clear that although the surgical field has seen major progress since early implant surgical techniques in the 1980s, major challenges still exist with hard tissue augmentation procedures. This review will discuss these challenges that are increased and often specific to bone graft healing, and which are becoming more common as implant site development often requires bone augmentation to improve volume or contour deficiencies. The risk factors that patients may present with that will affect outcomes with bone augmentation procedures are identified, and recommendations for the prevention of complications or managing complications once they have occurred are provided.

The smiling scan technique: Facially driven guided surgery and prosthetics.

PURPOSE: To introduce a proof of concept technique and new integrated workflow to optimize the functional and esthetic outcome of the implant-supported restorations by means of a 3-dimensional (3D) facially-driven, digital assisted treatment plan. METHODS: The Smiling Scan technique permits the creation of a virtual dental patient (VDP) showing a broad smile under static conditions. The patient is exposed to a cone beam computed tomography scan (CBCT), displaying a broad smile for the duration of the examination. Intraoral optical surface scanning (IOS) of the dental and soft tissue anatomy or extraoral optical surface scanning (EOS) of the study casts are achieved. The superimposition of the digital imaging and communications in medicine (DICOM) files with standard tessellation language (STL) files is performed using the virtual planning software program permitting the creation of a VDP. CONCLUSIONS: The smiling scan is an effective, easy to use, and low-cost technique to develop a more comprehensive and simplified facially driven computer-assisted treatment plan, allowing a prosthetically driven implant placement and the delivery of an immediate computer aided design (CAD) computer aided manufacturing (CAM) temporary fixed dental prostheses (CAD/CAM technology).

Temporary Shell Proof-of-Concept Technique: Digital-Assisted Workflow to Enable Customized Immediate Function in Two Visits in Partially Edentulous Patients

The growing interest in minimally invasive implant placement and delivery of a prefabricated provisional prosthesis immediately, thus minimizing "time to teeth," has led to the development of numerous 3-dimensional (3D) planning software programs. Given the enhancements associated with fully digital workflows, such as better 3D soft-tissue visualization and virtual tooth rendering, computer-guided implant surgery and immediate function has become an effective and reliable procedure. This article describes how modern implant planning software programs provide a comprehensive digital platform that enables efficient interplay between the surgical and restorative aspects of implant treatment. These new technologies that streamline the overall digital workflow allow transformation of the digital wax-up into a personalized, CAD/CAM-milled provisional restoration. Thus, collaborative digital workflows provide a novel approach for time-efficient delivery of a customized, screw-retained provisional restoration on the day of implant surgery, resulting in improved predictability for immediate function in the partially edentate patient.

New Bone Formation Process Using Bio-Oss and Collagen Membrane for Rat Calvarial Bone Defect: Histological Observation.

PURPOSE: We carried out guided bone regeneration of cranial bone defects in rats using the bovine bone substitute Bio-Oss and a collagen membrane and performed histological observations of the bone repair process. MATERIALS AND METHODS: Bone defects were created in the cranial bones of 30 15-week-old Sprague-Dawley rats. We made 3 groups. A is unfilled, B is Bio-Oss, and C is Bio-Oss plus a collagen membrane. At 4 or 8 weeks postoperatively, tissue samples were taken. The Kawamoto technique was used for histological evaluation. RESULTS: There was no new bone formation in group A. In groups B and C, new bone formation was evident around the Bio-Oss. In group C, new bone formation was evident in the centers of the bone defects, detached from the cut edge of the cranial bone. CONCLUSION: Our results suggested that the Bio-Oss acts as a scaffold for bone repair, and the use of a collagen membrane may anchor the Bio-Oss closely to the cranial bone and assist the bone repair response.

Is Bone Morphogenetic Protein-2 as Effective as Alveolar Distraction Osteogenesis for Vertical Bone Regeneration?

PURPOSE: The aim of this study was to assess the clinical effectiveness of alveolar distraction osteogenesis (ADO) versus recombinant human bone morphogenetic protein-2 (rh-BMP-2) for vertical ridge augmentation. Few data have been published on vertical bone regeneration using rh-BMP-2. MATERIALS AND METHODS: The authors implemented a retrospective cohort study and enrolled a sample composed of patients with deficient alveolar vertical bone height. The primary predictor variable was vertical augmentation with BMP-2 and a titanium mesh or ADO. The primary outcome variable was gain in vertical bone height (millimeters) measured using computed tomography. The secondary outcome variable was postoperative complications, namely need for further grafting before or simultaneous with implant placement, soft tissue dehiscence, paresthesia, infection, implant failure, and pain. Other outcomes included implant stability at time of placement and follow-up (implant stability quotient by resonance frequency analysis), surgical time (minutes), and total treatment time until implant placement (weeks). Other study variables included location of reconstruction (maxilla or mandible). Appropriate bivariate statistics were computed and statistical significance was set a P value less than .05. RESULTS: The retrospective review yielded 21 patients in the BMP group and 19 in the ADO group. For the BMP-2 group, the average vertical bone gain was 2.96 ± 1.8 mm overall (maxilla, mean 3.6 ± 3.1 mm; mandible, mean 2.32 ± 1.8 mm). For the ADO group, this gain was 4 ± 1.69 mm overall (maxilla, mean 2.8 ± 1.94 mm; mandible, mean 5.2 ± 4.67 mm). For complications, group BMP showed a statistically minor tendency for more postoperative problems, such as wound dehiscence. For implant survival, group BMP showed a 92.2% survival rate versus 96.3% in group ADO at 3 to 45 months after delivery of the prosthesis (average, 22 months). CONCLUSION: The 2 techniques showed similar values in absolute vertical bone gain. Group ADO showed a slightly better outcome in outright vertical regenerative potential, albeit with a more frequent need for regrafting before and simultaneous with implant placement. Group BMP showed a lesser need for regrafting, despite having a higher postoperative complication rate.

Newly Formed Bone Induced by Recombinant Human Bone Morphogenetic Protein-2: A Histological Observation.

PURPOSE: To observe, histologically, bone induced by recombinant human bone morphogenetic protein-2 (rhBMP-2) in onlay grafted and sinus lifted alveolaris. MATERIAL AND METHODS: Eighteen patients were treated with rhBMP-2 at concentration 1.5 mg/mL with an absorbable collagen sponge (ACS). The treated bone was harvested with small trephine bur at 5 or 7 months after surgery for the micro Computer Scanning (CT) and light microscopic observation. RESULTS: Micro CT showed clearly 3-dimensional trabecular bone structure. New bone formation and bone marrow structure were observed in the observed area. Osteoblastic cells existed along the new bone, and osteopontin was localized in the bone matrix weakly. In the connective tissue around the new bone, many CD34-positive blood vessel cells were present. Some tartrate-resistant acid phosphatase (TRAP)-positive osteoclastic cells were observed around bone at this stage. CONCLUSION: The application of rhBMP-2 with ACS induced a new bone accompanied by blood vessels in atrophied alveolaris. This suggests that rhBMP-2 is capable of osteoinductivity in human jaw.

Effect of length, diameter, intraoral location on implant stability.

OBJECTIVES: To quantitatively compare stability of dental implants with varying lengths, diameters, and intraoral locations. STUDY DESIGN: Retrospectively, 200 consecutive NobelReplace Tapered Groovy implants of varying lengths and diameters were evaluated via implant stability quotient readings at placement (T1) and follow-up (T2). Data were analyzed by analysis of variance and simple linear regression tests. RESULTS: Intraoral location was statistically significant at T1 and T2. Although implant diameter was not statistically significant, implant length resulted in T1 (P = .08) and T2 (P = .09), which may have a clinically relevant effect on implant stability. An overall implant survival rate of 98% was achieved. Gender and age did not seem to affect implant stability quotient values at placement, follow-up, or implant survival. CONCLUSIONS: Intraoral location is an important factor in implant stability, with implants placed in the mandible being more stable than implants placed in the maxilla both at T1 and T2. Length may have a clinically relevant effect on implant stability.

Guided surgery with tooth-supported templates for single missing teeth: A critical review.

AIM: To systematically scrutinise the scientific literature to evaluate the accuracy of computer-guided implant placement for single missing teeth, as well as to analyse the eventual clinical advantages and treatment outcomes. MATERIAL AND METHODS: The electronic and manual literature search of clinical studies published from January 2002 up to November 2015 was carried out using specified indexing terms. Outcomes were accuracy; implant and prosthetic failures; biological and mechanical complications; marginal bone loss (MBL); sulcus bleeding index (SBI); plaque score (PS); pink esthetic score [PES]; aesthetic and clinical outcomes. RESULTS: The search yielded 1027 relevant titles and abstracts, found during the electronic (n = 1020) and manual (n = 7) searches. After data extraction, and screening of titles, abstracts, and full-texts, 32 studies fulfilled inclusion criteria and were included in the critical review: two randomised controlled clinical trials, six prospective observational single cohort studies, one retrospective observational study, three in vitro comparative studies, 10 case reports and 10 systematic reviews. A total of 209 patients (18 to 67 years old) were treated with 342 implants using computer-guided implant surgery. The follow-up ranged from 12 to 52 months. The cumulative survival rate ranged from 96.5% to 100%. Eleven implant planning softwares and guided surgery systems were used and evaluated. CONCLUSIONS: Computer-guided surgery for single missing teeth provides comprehensive treatment planning, reliable implant positioning, favourable clinical outcomes and aesthetics. A tooth-supported template for the treatment of single missing teeth results in greater accuracy of implant positioning than with mucosa-supported or bone-supported templates. The limited scientific evidence available suggests that guided surgery leads to implant survival rates as good as conventional freehand protocols. Computer-guided surgery implies additional costs, that should be analysed in terms of cost-effectiveness, considering the reduction of surgery time, postoperative pain and swelling, as well as, the potential increased accuracy. Long-term randomised clinical trials are eagerly needed to investigate the clinical performance of guided surgery in partially edentate patients.

Single implants in dorsal areas - A systematic review.

AIM: This study evaluated the efficacy of replacing single missing teeth in the posterior quadrants of the maxilla and/or mandible with an implant-supported dental prosthesis. MATERIAL AND METHODS: Three scientific literature databases - Medline (Pubmed), Ovid Medline and Cochrane Central Register of Controlled Trials (CENTRAL) - were used to perform a search of publications over a period from 1985 to 2014. One hundred and forty one (141) articles were reviewed; 36 articles met the inclusion criteria and were included in the final review. RESULTS: The survival rates, success rates and mean bone loss for immediate implant placement were 96.9%, 100% and 0.85 mm, respectively. The survival rates, success rates and mean bone loss for delayed implant placement were 96.8%, 94.1% and 0.55 mm respectively. The survival rate, success rate and the mean bone loss in studies comparing immediate versus delayed implant placement showed 96.8% and 96.3%, 85.8% and 93.3%, and 0.57 ± 0.57 mm and 0.55 ± 0.37 mm, respectively. CONCLUSION: The prognosis for single molar implants provides a viable treatment option for replacing a single missing tooth in the posterior quadrants of the maxilla and mandible. There does not appear to be a significant difference in the survival rates of immediately placed implants compared with delayed implant placement. However, the success rates were slightly higher with delayed loading protocols than immediate loading protocols.

Four-implant overdenture fully supported by a CAD-CAM titanium bar: A single-cohort prospective 1-year preliminary study.

STATEMENT OF PROBLEM: In patients with an altered skeletal maxillomandibular relationship and bone resorption, the rehabilitation of edentulous jaws by combining 4 implants, 2 straight medially and 2 tilted distally, may be preferred to avoid a bone augmentation procedure. PURPOSE: The purpose of this single cohort 1-year prospective study was to evaluate the clinical performance of a 4-implant overdenture fully supported by a computer-aided designed and computer-aided manufactured (CAD-CAM) titanium bar. MATERIAL AND METHODS: This single cohort prospective study included edentulous participants rehabilitated with a 4-implant overdenture in 1 of the 2 jaws. The outcomes were implant and prosthetic survival and success rates, any biologic and technical complications, periimplant marginal bone loss, changes in the oral health impact profile (OHIP), bleeding on probing, and the plaque index. RESULTS: Eighteen participants received 72 implants. One year after implant placement, no implants or prosthesis had failed, and no biologic or technical complications had been observed. At the 1-year follow-up, the mean marginal bone loss was 0.29 ±0.16 mm. The OHIP summary scores demonstrated a significant improvement in oral health-related quality of life. At the 1-year follow-up, positive bleeding was found in 2 participants (11.1%) around 3 implants (4.1%). Three participants (16.6%), accounting for 5 implants (6.9%), showed a slight amount of plaque. CONCLUSIONS: A 4-implant overdenture supported by a CAD-CAM titanium bar may be a reliable option for the treatment of the edentulous mandible and maxilla over a 1-year period. Oral health-related quality of life significantly improved in all treated participants.

The Predictive Value of Resonance Frequency Analysis Measurements in the Surgical Placement and Loading of Endosseous Implants.

PURPOSE: The purpose of this study was to investigate the predictive value of resonance frequency analysis in assessing implant survival. This was accomplished by determining the correlation between implant stability quotients (ISQs) and implant survival following different placement staging (1-stage vs 2-stage) and loading (early vs traditional) protocols. MATERIALS AND METHODS: A retrospective study was performed on implant patient data collected over a 5-year period. Patients ranged in age from 16 to 91 years. We analyzed 703 implants during placement and 1,254 implants before loading. All implants were placed with respective ISQs recorded by 1 oral and maxillofacial surgeon. Receiver operating characteristic (ROC) statistical analysis was used to calculate sensitivity and specificity values corresponding to various ISQ cutoff points for different placement staging and loading protocols; χ(2) tests were used to identify significant differences. RESULTS: In predicting implant failure, sensitivity progressively increased and specificity decreased as ISQ cutoff values increased. All failures occurred at an ISQ less than 66 for the placement staging protocol and an ISQ less than 67 for the loading protocol. When ISQ values were below 60, higher survival rates were observed when implants were placed using a 2-stage rather than a 1-stage placement staging protocol (P < .05). The area under the ROC curve for placement staging was 0.80, and the area under the ROC curve for loading was 0.89. An implant survival rate of over 98% was achieved. CONCLUSIONS: Resonance frequency analysis is a noninvasive technique used to measure the stability of implants and to help guide placement staging and loading protocols. This study showed that increasing ISQ values correlated with increased sensitivity in detecting implant failure. Given the high survival rates of dental implants, additional studies can further elucidate the relationship between ISQ values and survival rates.

Sinus membrane perforations and the incidence of complications: a retrospective study from a residency program.

OBJECTIVE: The purpose of this study is to evaluate sinus membrane perforations and the incidence of complications in a residency program. STUDY DESIGN: Data from 107 consecutive direct sinus augmentation procedures were reviewed retrospectively from 2008 to 2012. DISCUSSION: All perforations were repaired intraoperatively with the use of a collagen tape. Intraoperative membrane perforations were observed in 64 of 107 cases (59.8%). Of the perforations, 58 were less than 5 mm in diameter and 6 were 5 mm or greater in diameter. It was found that there were 6 cases (5.6%) that experienced postoperative complications. Of those, 3 occurred in cases with no perforations, 2 with perforations less than 5 mm in diameter, and 1 with a perforation 5 mm or more in diameter. These differences were not statistically significant (P > .05). All observed post-operative complications were related to symptoms of acute infection. CONCLUSIONS: Although membrane perforation was a frequent intraoperative finding, there was no evidence that the presence and size of membrane perforation influences the likelihood of postoperative complications.

The Implant Biologic Pontic Designed Interface: Description of the Technique and Cone-Beam Computed Tomography Evaluation.

PURPOSE: The study aims to evaluate clinically the thickness of the alveolar ridge mucosa underneath a zirconia implant-supported restoration with a modified ovate pontic. MATERIALS AND METHODS: Sixty-five patients, 32 women and 33 men (mean age: 65.5 years; range 38-81), were included. A total of 383 implants (303 in the maxilla; 80 in the mandible), supporting 81 full or partial fixed dental prostheses (65 in the maxilla; 16 in the mandible), were either cement- or screw-retained. Three years after loading, a total of 219 pontic sites (153 in the maxilla; 66 in the mandible) were measured, and the thickness of the alveolar ridge mucosa between the prosthetic surface and the underlying bone crest were recorded. RESULTS: The overall implant and prosthesis survival rates at 3 years were 98.7% and 100%, respectively. No implant complications were reported, scoring a cumulative implant success rate of 100%. In the maxilla, the overall mean thickness of the alveolar ridge mucosa was 2.32 ± 0.57 mm. In the mandible, the overall mean thickness of the alveolar ridge mucosa was 2.20 ± 0.62 mm. There was no statistical difference between the overall mean values in the maxilla and mandible (p = .471). CONCLUSION: This radiologic retrospective study suggests the existence of a physiological barrier, named prosthetic biological width, underneath a novel pontic-designed restoration.

Immediate loading with a novel implant featured by variable-threaded geometry, internal conical connection and platform shifting: three-year results from a prospective cohort study.

PURPOSE: To evaluate the clinical and radiological performance of an immediately loaded novel implant design over a 3-year period. MATERIALS AND METHODS: This prospective study includes 54 consecutive partially edentulous patients treated between December 2010 and October 2011. Outcome measures were: implant and prosthetic failures; biological and mechanical complications; marginal bone loss (MBL); sulcus bleeding index (SBI); and plaque score (PS). RESULTS: A total of 118 (29 narrow platform, 70 regular platform and 19 wide platform) NobelReplace Conical Connection implants were placed in both post-extraction sockets and healed sites and immediately loaded. The mean insertion torque was 63.4 ± 7.1 Ncm. One hundred out of 118 implants (84.7%) were inserted with a torque ranging between 55 and 70 Ncm. Each patient received a single prosthesis. At the 3-year follow-up, no patient dropped out and only two post-extractive implants failed (1.7%) in two patients (3.7%). The only complication (1.9%) observed was an event of periimplantitis, consisting of a mean mesiodistal peri-implant bone loss of 3.2 mm reported in a healed site of a smoker patient at the 2-year follow-up examination. No prosthesis failures were detected. The cumulative mean MBL between implant placements at the 3-year follow-up was 0.68 mm (95% CI: 0.44, 0.92). At the 3-year follow-up session, the SBI and PS were 5.7% and 15.4%, respectively. CONCLUSIONS: The NobelReplace Conical Connection implant can be considered as a valuable treatment option for immediate implant placement and loading in the partially edentulous patients over a 3-year period. Insertion torques ranging between 55 and 70 Ncm are not detrimental to osseointegration.

Mechanical versus biological stability of immediate and delayed implant placement using resonance frequency analysis.

PURPOSE: The purpose was to objectively measure the stability of immediately placed implants compared with implants placed at healed sites using implant stability quotient (ISQ) values obtained by resonance frequency analysis. MATERIALS AND METHODS: Data were collected from 137 Nobel Replace Tapered Groovy Implants placed in 85 patients 19 to 93 years old. All implants were placed by the same surgeon from May 2007 to October 2011. Forty-one implants were placed immediately after extraction with MasterGraft bone grafting material and 96 were placed in healed sites with no grafting material. ISQ values obtained by the Osstell ISQ System were recorded at the time of implant placement and at a subsequent follow-up appointment (T2). T2 was split into 2- to 3-month and 4- to 6-month groups depending on when their follow-up ISQ values were obtained. Data were analyzed using simple linear regression. RESULTS: Implants placed in healed sites had higher average ISQ values at implant placement compared with immediately placed implants; however, mean ISQ values in the 2 immediate implant groups exceeded the ISQ threshold of 65. Immediately placed implants in the 2- to 3-month and 4- to 6-month groups had average ISQ values of 65.60 and 68.65, respectively, whereas implants placed in healed sites had averages of 76.73 (2- to 3-month group) and 71.23 (4- to 6-month group). These differences were statistically significant (P < .05). At subsequent follow-up appointments, implants placed in healed sites had higher mean ISQ values. Implants in healed sites had ISQ averages of 79.58 (2- to 3-month group) and 77.31 (4- to 6-month group), whereas immediately placed implants had averages of 73.88 and 70.14. These differences were statistically significant (P < .05). Moreover, these mean ISQ values in immediate implants exceeded the ISQ threshold of 65. CONCLUSION: Although mean ISQ values of immediately placed implants are lower than those of delayed implants at implant placement and follow-up appointments, immediate implant mean ISQ values consistently remain higher than the clinically successful ISQ threshold of 65 throughout the osseointegration process. These results support the immediate placement of implants in extraction sockets under favorable conditions.

Computed tomography-based, template-guided implant placement and immediate loading: an 8-year clinical report.

This report presents an 8-year follow-up of a patient treated with computer-assisted implant planning, template-guided implant placement, and immediate loading. A preoperative diagnostic evaluation resulted in a more predictable implant placement with respect to anatomic structures and the planned prosthesis. Implants were placed in both the maxilla and the mandible, and immediate loading in both arches was provided.

Three-year post-loading results of a randomised, controlled, split-mouth trial comparing implants with different prosthetic interfaces and design in partially posterior edentulous mandibles.

PURPOSE: To compare the clinical and radiological outcomes of two implant designs with different prosthetic interfaces and neck configurations. MATERIALS AND METHODS: Thirty-four partially edentate patients randomly received at least one NobelActive implant (Nobel Biocare, Göteborg, Sweden) with back-tapered collar, internal conical connection and platform shifting design, and one NobelSpeedy implant (Nobel Biocare) with external hexagon and flat-to-flat implant-abutment interface according to a split-mouth design. Follow-up continued to 3 years post-loading. The primary outcome measures were the success rates of the implants and prostheses, and the occurrence of any surgical and prosthetic complications during the entire follow-up. Secondary outcome measures were: horizontal and vertical peri-implant marginal bone level (MBL) changes, resonance frequency analysis values at implant placement and loading (4 months), sulcus bleeding index (SBI) and plaque score (PS). RESULTS: No drop-out occurred. No implants and prostheses failures were observed to the 3-year follow-up. MBL changes were statistically significant different with better results for the NobelActive implants for both horizontal and vertical measurements (P = 0.000). After 3 years post-loading, the NobelActive implants underwent a mean vertical bone resorption of 0.66 mm, compared with 1.25 mm for the NobelSpeedy Groovy implants (P = 0.000); the mean horizontal bone resorption was 0.19 mm for the NobelActive implants and 0.60 mm for the NobelSpeedy Groovy implants (P = 0.000). A high ISQ value was found for both implants, and no statistically significant difference was found for ISQ mean values between interventions (P = 0.941 at baseline; P = 0.454 at implantabutment connection; P = 0.120 at prosthesis delivery). All implants showed good periodontal health at the 3-year-in-function visit, with no significant differences between groups. CONCLUSION: The results of this research suggest that in well-maintained patients, the MBL changes could be affected by the different implant design. After 4 months of unloaded healing, as well as after 3 years in function, both implants provided good results, however vertical and horizontal bone loss had statistically significant differences between the two groups (difference of 0.58 ± 0.10 mm for the vertical MBL, and 0.4 ± 0.05 mm for the horizontal MBL), with lower values in the Nobel Active implants, compared to the NobelSpeedy Groovy implants.

Minimally invasive transcrestal guided sinus lift (TGSL): a clinical prospective proof-of-concept cohort study up to 52 months.

PURPOSE: This study describes a new procedure for sinus elevation using computer-guided planning and guided surgical approach through the use of computer-aided design (CAD)/computer-aided manufacturing (CAM)-generated surgical template in combination with expander-condensing osteotomes thus providing a minimally invasive surgical technique. MATERIALS AND METHODS: Sixty-six consecutive patients were treated with 136 implants placed by transcrestal-guided sinus floor elevation technique and the patients were followed for at least 3 years in function. The drilling protocol is customized based on the bone density of each implant site to achieve an insertion torque ranging between 45 and 55 Ncm. Titanium temporary abutments were connected to the implants with prosthetic screws tightened to 35 Ncm and an acrylic resin provisional restoration was adapted and delivered immediately. Six months after initial loading, a definitive CAD/CAM-generated restoration was delivered. Outcome measurements assessed were implant and prosthesis survival rate, biological or biomechanical complications, marginal bone level changes, total alveolar ridge bone height before and after procedure, periodontal parameters measured as well as patient's perception of pain levels during recovery period. RESULTS: Mean follow-up was 43.96 (range from 36 to 52) months. Cumulative implant survival rate was 98.53% at 3 years. No biological or mechanical complications were encountered and no prosthetic failures occurred during the entire follow-up period. Mean marginal bone loss (MBL) during the first year of function was 0.33 ± 0.36 mm, while at the 3-year follow-up, the mean MBL was 0.51 ± 0.29 mm. The mean residual bone height of the alveolar crest prior to grafting was of 6.7 ± 1.6 mm (range 5.1-9.2 mm), while, the mean bone height gained was 6.4 ± 1.6 mm (range 3.2-8.1 mm). All patients reported low levels of pain and found to have normal periodontal parameters. CONCLUSION: This proof-of-concept study suggests that the use of guided surgery to perform transcrestal maxillary sinus floor elevation for alveolar ridge height augmentation is a successful minimally invasive technique for the short- to medium-term follow-up, thus avoiding the extended treatment time and morbidities associated with maxillary sinus floor augmentation.