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.

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.

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.

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.

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.

Histologic evaluation of human alveolar sockets treated with an artificial bone substitute material.

This study involved a histologic, enzyme histologic, immunohistologic, and three-dimensional microstructure evaluating the extent of osteogenesis and repair in the human alveolar extraction socket achievable with an artificial bone substitute. After tooth extraction in 7 patients, extraction sockets were filled with Mastergraft (15% hydroxyapatite, 85% ß-tricalcium phosphate complex). Radiomicrographs and histologic examinations were performed on samples obtained during dental implant placement procedure. On micro-computed tomography, new bone was observed in all collected samples, and osteogenesis was observed to have taken place around the artificial bone substitute. Histologically, active osteogenesis was found throughout the region observed. Addition of new bone around the Mastergraft was observed, and osteoblast-like cells were present. Cells that had partially invaded the artificial bone included tartrate-resistant acid phosphate-positive and CD34-positive cells. These findings indicate that the Mastergraft artificial bone induced osteogenesis in the jawbone and seemed effective for repairing bone defects.

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.

Pivotal, randomized, parallel evaluation of recombinant human bone morphogenetic protein-2/absorbable collagen sponge and autogenous bone graft for maxillary sinus floor augmentation.

PURPOSE: The purpose of this prospective study was to evaluate the safety and effectiveness of recombinant human morphogenetic protein-2 (rhBMP-2) on an absorbable collagen sponge (ACS) compared with an autogenous bone graft when used for 2-stage maxillary sinus floor augmentation. The study assessed new bone formation, placement integration, and functional loading after 6 months and long term for 2 years. MATERIALS AND METHODS: A total of 160 subjects were randomized, enrolled, and followed from January 1999 to February 2004 at 21 centers in the United States. The subjects with less than 6 mm of native bone height were treated with 1.50 mg/mL rhBMP-2/ACS or with an autograft. The height and density measurements were quantified by computed tomography scans. Core biopsies were obtained at dental implant placement and used for histological analysis. Safety was evaluated by oral examinations, radiographs, serum chemistries, and hematology. RESULTS: A significant amount of new bone was formed by 6 months postoperatively in each group. The mean change in bone height in the rhBMP-2/ACS subjects was 7.83 +/- 3.52 mm versus 9.46 +/- 4.11 mm for the bone graft subjects. At 6 months after dental restoration, the induced bone in the rhBMP-2/ACS group was significantly denser than that in the bone graft group. No marked differences were found in the histologic parameters evaluated between the 2 groups. The new bone was comparable to the native bone in density and structure in both groups. The success rate for the rhBMP-2/ACS group was 79% (64 of 81 subjects), and 201 of 251 implants placed in the bone graft group and 199 of 241 implants placed in the rhBMP-2/ACS group were integrated, retained, and functional at 6 months after loading. No adverse events were deemed related to the rhBMP-2/ACS treatment. The autograft group was noted to have a 17% rate of long-term parasthesia, pain, or gait disturbance related to the bone graft harvest. CONCLUSIONS: The results of our multicenter, randomized, prospective, clinical trial have shown the effectiveness and safety of rhBMP-2/ACS compared with bone graft for sinus floor augmentation. The study's primary endpoint was exceeded, and the implants placed in rhBMP-2/ACS and bone graft groups performed similarly after functional loading.

The single-tooth dental implant: practical guidelines for hard tissue augmentation.

With the increased popularity of implants and focus on .. esthetics, there is great emphasis on idealized bone foundation and soft tissue contours. The goal of reconstructive procedures is to provide peri-implant bone that support and maintain gingival contours. This article reviews ridge deficiency diagnosis and predicts the need for bone augmentation before tooth extraction. It also presents early intervention to minimize bone loss, various bone reconstruction techniques, and suggests predictable methods for different clinical scenarios.

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.

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).

Which hard tissue augmentation techniques are the most successful in furnishing bony support for implant placement?

PURPOSE: A variety of techniques and materials have been used to establish the structural base of osseous tissue for supporting dental implants. The aim of this systematic review was to identify the most successful technique(s) to provide the necessary alveolar bone to place a dental implant and support long-term survival. METHODS: A systematic online review of a main database and manual search of relevant articles from refereed journals were performed between 1980 and 2005. Updates and additions were made from September 2004 to May 2005. The hard tissue augmentation techniques were separated into 2 anatomic sites, the maxillary sinus and alveolar ridge. Within the alveolar ridge augmentation technique, different surgical approaches were identified and categorized, including guided bone regeneration (GBR), onlay/veneer grafting (OVG), combinations of onlay, veneer, interpositional inlay grafting (COG), distraction osteogenesis (DO), ridge splitting (RS), free and vascularized autografts for discontinuity defects (DD), mandibular interpositional grafting (MI), and socket preservation (SP). All identified articles were evaluated and screened by 2 independent reviewers to meet strict inclusion criteria. Articles meeting the inclusion criteria were further evaluated for data extraction. The initial search identified a total of 526 articles from the electronic database and manual search. Of these, 335 articles met the inclusion criteria after a review of the titles and abstracts. From the 335 articles, further review of the full text of the articles produced 90 articles that provided sufficient data for extraction and analysis. RESULTS: For the maxillary sinus grafting (SG) technique, the results showed a total of 5,128 implants placed, with follow-up times ranging from 12 to 102 months. Implant survival was 92% for implants placed into autogenous and autogenous/composite grafts, 93.3% for implants placed into allogeneic/nonautogenous composite grafts, 81% for implants placed into alloplast and alloplast/xenograft materials, and 95.6% for implants placed into xenograft materials alone. For alveolar ridge augmentation, a total of 2,620 implants were placed, with follow-up ranging from 5 to 74 months. The implant survival rate was 95.5% for GBR, 90.4% for OVG, 94.7% for DO, and 83.8% for COG. Other techniques, such as DD, RS, SP, and MI, were difficult to analyze because of the small sample size and data heterogeneity within and across studies. CONCLUSIONS: The maxillary sinus augmentation procedure has been well documented, and the long-term clinical success/survival (> 5 years) of implants placed, regardless of graft material(s) used, compares favorably to implants placed conventionally, with no grafting procedure, as reported in other systematic reviews. Alveolar ridge augmentation techniques do not have detailed documentation or long-term follow-up studies, with the exception of GBR. However, studies that met the inclusion criteria seemed to be comparable and yielded favorable results in supporting dental implants. The alveolar ridge augmentation procedures may be more technique- and operator-experience-sensitive, and implant survival may be a function of residual bone supporting the dental implant rather than grafted bone. More in-depth, long-term, multicenter studies are required to provide further insight into augmentation procedures to support dental implant survival.

Histomorphometric and fluorescence microscopic evaluation of interfacial bone healing around 3 different dental implants before and after radiation therapy.

PURPOSE: Radiation therapy influence on bone healing around 3 types of endosseous dental implants in dogs was evaluated. MATERIALS AND METHODS: Implants with 3 different surfaces (A = machined commercially pure titanium screws, B = commercially pure titanium plasma spray-coated cylinders, C = hydroxyapatite [HA] -ceramic coated cylinders) were first implanted unilaterally into the right posterior edentulous mandibles of 7 dogs as nonirradiated controls. After 12 weeks without functional loading and after sequential fluorochrome labeling these implants were retrieved by block dissection. In this same surgery, implants were placed on the contralateral side. Three weeks postimplantation the implant-containing hemimandibles were Cobalt 60 irradiated with the biologic equivalent of 5,000 cGy. Twelve weeks postimplantation and after labeling these irradiated implants were retrieved at sacrifice. On scanning electron, light, and fluorescence microscopic images of undecalcified longitudinal ground sections of the implants with surrounding tissues, percent bone-to-implant contact (% BIC), bone formation, and remodeling were histometrically and subjectively evaluated. RESULTS: Woven bone formation started 1 week after implantation at the implant interfaces on both the nonirradiated and the irradiated sides. Average BICs (total/cortical/spongious bone bed) of 26%/49%/36% for surface A, 46%/48%/64% for surface B, and 81%/83%/78% for surface C were observed. In the irradiated hemimandibles average BICs (total/cortical/spongious bone bed) were reduced to 11%/9%/4% for surface A, 43%/46%/43% for surface B, and 63%/85%/76% for surface C, with increased resorption of peri-implant bone and retarded bone formation after irradiation. DISCUSSION: Reductions of total % BIC in all irradiated implants, though not statistically significant, were significant (P < or = .05) on implant surfaces A and B in the spongious bone bed. CONCLUSION: Retarded bone formation on surfaces A and B in the spongious bone bed represented a more radiation-sensitive situation at the time of radiation onset compared to advanced bone formation and maturation at surface C.

Evidence-based research in alternative protocols to dental implantology: a closer look at publication bias.

Several techniques exist for the surgical placement of dental implants. The aim of this study was to assess systematically, the efficacy of these protocols by the evidence-based perspective. Five best-case studies involving 607 early/immediately loaded implants and 300 conventionally loaded implants were identified by examining the available literature and rigorous inclusion/exclusion criteria. Overall analyses demonstrated a 98.4 percent success rate for the early/immediate procedure and a 95.3 percent for the conventional protocol. Success rates in the articles reviewed were based on implant survival over a follow-up period of between one to two years. A meta-analysis was generated to evaluate the presented evidence and to aid in decision-making. Despite its common implementation, this technique presents many caveats, among which publication bias is one of the most common. To investigate the possible presence of publication bias, a funnel plot analysis complemented several statistical tests. By means of the systematic investigation of dental implants, the authors' results confirm the presence of publication bias in implant dentistry literature, which strongly suggests that clinicians ought not base their decisions solely on the results presented by a few published studies. Rather, it is recommended that clinicians cautiously draw conclusions and seek studies that present accountable and clinically relevant results. Furthermore, it is suggested that clinicians attend seminars to learn of the effective advances in evidence-based dentistry, so as to develop the ability to easily detect inadequate literature due to attempted correlation with the most current research. It is also recommended that additional research is necessary to analyze which fields of research are more prone to bias, thus forewarning clinicians before formulating clinical conclusions.

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.

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.