Implant Placement Procedures Research Articles

Tilted Implant Concept for Full Mouth Immediate Loading Restoration

Tilted Implant Concept for Full Mouth Immediate Loading Restoration

Application of Modified Bony Lid Technique to Remove or Replace Compromised Implants

The original bony lid technique involves removing window of cortical bone using a microsaw, removing a failing implant through the window, and then replacing the bone into its original position. The purpose of this case series was to present modifications to the bony lid technique to improve outcomes. Ten patients (9 men and 1 woman) aged between 47 and 89 years were treated during a 5-year period with modifications to the bony lid technique. Modifications to the bony lid technique included restricting the size of the bony lid, use of a long shank drill, performing guided bone regeneration, immediate implant placement, and providing rigid fixation. No complications occurred in the 10 cases presented in this case series. An immediate implant placement procedure was performed in 3 of the 10 patients treated. Fixation screws and a microplate were used to fix the bony lid in 1 patient. Allogenic bone was used in another case. Additional trephine and thin drills were used in 2 cases in the mandibular molar area. Replacing failing dental implants can be successfully accomplished by removing cortical bone on the buccal aspect of the implant and then replacing this bone after the implant is removed or replaced. Using allogenic bone, fixation screws, microplates, and thin drills can help facilitate the success of this procedure.

Real‐time thermographic analysis of low‐density bone during implant placement: a randomized parallel‐group clinical study comparing lateral condensation with bone drilling surgical technique

To compare the effect of two surgical techniques, lateral condensation and bone drilling, on changes in temperature of the adjacent low-density bone during implant placement into posterior maxilla and to investigate the influence of the host factors - age, gender, region of implantation, bone density, and thickness of the cortical bone at the recipient sites. Local bone temperature was measured thermographically during implant placement into posterior maxilla following lateral bone condensing (test group) or bone drilling (controls). The main study outcomes were baseline bone temperature prior to implantation and maximum bone temperature recorded during implantation. Early implant success was evaluated after 6 months of healing. A total of 40 implants were randomly allocated to test and control groups and placed into maxillary premolar and/or molar region of 18 participants of both genders and average age of 51.74 years. All recorded bone temperatures were below the threshold for thermal necrosis. Although both groups showed significant increase in bone temperature during implant placement procedure (P ≤ 0.0005), it was significantly higher for bone condensing compared with drilling (P ≤ 0.0005; 3.79 ± 1.54°C; 1.91 ± 0.70°C respectively). No host factor was singled out as a significant predictor of bone temperature changes, although trend of higher increase was observed in young patients, regardless of gender, during implant placement procedure into maxillary first premolar region with bone density type 3 and cortical layer thicker than 1 mm. Early implant success rate after 6 months follow-up was 100%. Although both surgical techniques, bone condensing and bone drilling, can be considered safe regarding their thermal effect on the bone of posterior maxilla, bone drilling is associated with fewer local bone heating during implantation. Host factors do not affect the bone thermal changes significantly.

Applications of computer-aided design/computer-assisted manufacturing technology in dental implant planning

Computer-aided design/computer-assisted manufacturing (CAD/CAM) technology facilitates proper diagnosis, treatment planning and fabrication of a surgical guide template that enables the clinician to plan the implant placement procedure prior to surgical intervention. This development in implant dentistry allows an interdisciplinary approach to patient treatment. The purpose of this review article is to review and analyze the current available literature published on CAD/CAM-based dental implant planning and to provide a detailed discussion on the step-wise procedures involved in using this technology for dental implant planning and placement. Literature published over the past 20 years was selected and reviewed. The advantages and disadvantages associated with CAD/CAM-based dental implant planning were analysed. The various steps involved in fabrication of a CAD/CAM-based surgical guide template, namely, the fabrication of a radiographical template, the computerized tomography scan, implant planning stage and the fabrication of a surgical drill guide, were thoroughly reviewed and discussed. CAD/CAM technology has facilitated flapless surgeries by improvising on pre-surgical planning. Moreover, they have facilitated restoration-driven surgeries by integrating the restorative determinants into the surgical planning. Various clinical reports have demonstrated the use of this system in dental implant planning and in the involved surgical procedure. However, very few studies on the accuracy and reliability of this system have been carried out. Thus, the clinical applicability of this system is still questionable and long-term longitudinal studies are certainly needed before integrating this system into routine practice.

Guided surgery for a simple and predictable implant placement

The dental implant procedure has a long and proven track record to be one of the most predictable in terms of treatment outcome. This procedure has integrated itself as a part of routine treatment plans in dental offices because of increasing popularity and patient acceptance. In order to uphold this success, optimum diagnosis and treatment planning is crucial. Hence, computerized tomography aided imaging and template-guided surgery plays an important role in pre-placement planning and helps ensure positive outcomes. This article describes the benefits of computer-guided surgery as compared with conventional implant placement procedures, along with a case report. Clinical Relevance to Interdisciplinary Dentistry Implant therapy requires a multidisciplinary approach. The prosthodontist needs to plan the situation with the end prosthesis in mind. The periodontist needs to preserve the already compromised bone. The surgeon needs to navigate the implant into critical areas.

Histomorphometric analysis following augmentation of the posterior mandible using cancellous bone‐block allograft

The present study was conducted to histologically and histomorphometrically evaluate the application of cancellous bone-block allografts for the augmentation of the posterior atrophic mandible. Twenty-four consecutive patients underwent augmentation with cancellous bone-block allografts in the posterior mandible. A bony deficiency of at least 3 mm horizontally and/or vertically according to CT para-axial reconstruction served as inclusion criteria. Following 6 months, 85 implants were placed and a cylindrical sample core was collected. All specimens were prepared for histological and histomorphometrical examination. Implant survival rate was 95.3%. Follow-up ranged 12-66 months (mean 43 ± 19 months). The mean newly formed bone was 44 ± 28%, that of the residual cancellous bone-block allograft 29 ± 24%, and of the marrow and connective tissue 27 ± 21%. Statistically significant histomorphometric differences regarding newly formed bone (69% vs. 31%, p = 0.05) were found between younger (< 45 years) and older (> 45 years) patients, respectively. Histomorphometric differences regarding residual cancellous bone-block allograft (17% vs. 35%) and of the marrow and connective tissue (14% vs. 34%) were not statistically significant. Cancellous bone-block allograft is biocompatible and osteoconductive, permitting new bone formation following augmentation of extremely atrophic posterior mandible with a two-stage implant placement procedure. New bone formation was age-dependent.

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% β-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.

Replacement of Vertically Root-Fractured Endodontically Treated Teeth With Immediate Implants in Conjunction With a Synthetic Bone Cement

The purpose of this prospective study was to evaluate the clinical outcome of implants immediately placed into fresh extraction sockets for the replacement of endodontically treated teeth with signs of vertical root fracture. Sixteen partially edentulous patients, with 1 tooth scheduled for extraction and showing clinical signs and symptoms and/or radiological evidence of vertical root fracture, were included in the study. Sixteen transmucosal implants were installed immediately after extraction and careful debridement. The gap between the implant surface and the socket walls was filled using synthetic bone grafting cement. Prosthetic phase occurred 3 to 4 months after surgery. Implant success and survival and radiographic bone loss were evaluated after 1 year of function. Patient satisfaction for mastication function, phonetics, and aesthetics was also assessed by means of a questionnaire. No implant failure occurred. The overall implant success and survival was 100% at 1 year. The mean follow-up was 13.5 months. All prostheses were successful. Periimplant bone loss after 1 year averaged 0.48 ± 0.20 mm. All patients reported full satisfaction for mastication function, phonetics, and aesthetics. The use of a synthetic bone grafting cement in combination with immediate implant placement procedure can be considered a safe, effective, and predictable treatment option for the rehabilitation of fresh postextraction sockets.

Endoscopic Approach to Dental Implantology

To describe an innovative miniature visualization surgical endoscope and endoscopic techniques applicable to dental implant procedures. A newly developed modular dental implant endoscope is introduced, and the first impressions from its use in different implant procedures are reported. Details of the device that combines an endoscope, irrigation cannulas, and a surgical microinstrument channel are presented. The advantages of using it in dental implant procedures are described, and examples of how miniature visualization and surgical endoscopic techniques can be applied to increase the success of implantation are outlined. The new modular implant endoscope accurately identified all microanatomical and pathological structures, and simplified dental implant procedures. Endoscopy should be considered not only for intraoperative observation and assessment of implant sites, but also should be applied for active assistance during implant placement procedures.

Evaluation of Bioactive Glass as a Bone Graft Extender in Sinus Elevation Surgeries

This study evaluated histologically and radiographically sinus elevation surgeries using PerioGlas (PG) in combination with autogenous bone (AB) or freeze dried bone (FDB).Methods: Thirty-two elevations were done in 27 patients with five patients receiving bilateral elevation. PerioGlas was mixed with AB or FDB in a 1:1 ratio. All sinus elevation and implant surgeries healed uneventfully. Histologic samples were obtained as part of the subsequent implant placement procedure. A total of 37 Bio-Lok implants, 10-13 mm in length were implanted.Results: All implants osseointegrated and successfully restored. Average bone gain at 6 months was 5.6 mm for PG + AB and 7.4 mm for PG + FDB with no clinically significant difference between either. PerioGlas, in addition to its osseous regenerative properties, displays excellent handling characteristics and with its osteostimulatory properties, can be used as a bone graft extender for sinus elevation surgeries.

Cholesterol Granuloma of the Maxillary Sinus Encountered during Floor Augmentation Procedure: A Case Report

Cholesterol granuloma (CG) is a foreign-body reaction to the deposition of cholesterol crystals. Its occurrence in the paranasal sinuses is very rare. This report describes a new case of maxillary sinus CG discovered incidentally during sinus-floor augmentation for dental implant placement in a 60-year-old female patient. The preoperative clinical and radiological examinations revealed a normal maxillary antrum with no evidence of sinus pathology. After lateral osteotomy, a dark-green, viscous soft tissue mass appeared through the thin mucous membrane inside the sinus. Enucleation and curettage of the sinus contents including the sinus membrane were performed for histopathologic analysis. The augmentation and implant placement procedures were postponed. Histopathologic analysis showed several fragments of granulation tissue containing diffuse cholesterol clefts surrounded by mixed chronic inflammatory cell infiltrate including plasma cells and lymphocytes. These features were compatible with the diagnosis of CG. The patient was followed up for 3 months after the first procedure, and a second attempt of sinus augmentation and dental implant insertion was then carried out. The inserted dental implants were followed up for 6 months without any complications. CG of maxillary sinus can be an incidental finding. For this reason, the final diagnosis can only be achieved after examination of the material under the microscope.

Experience of Maxillary Sinus Floor Augmentation in the Presence of Antral Pseudocysts

Sinus floor elevation is increasingly being used with implant placement procedures. However, certain surgical difficulties can develop, such as sinus membrane perforation, bleeding, anatomic variations, or some pathologies of the maxillary sinus. Maxillary antral pseudocysts are one of the most common benign pathologies of the maxillary sinus. Although some investigators have described the presence of this pathology as a contraindication, recent reports have demonstrated that pseudocysts of the maxillary sinus are not a contraindication for sinus augmentation. In these reports, maxillary sinus augmentations related to antral pseudocyst experiences are presented.

Spiral Computed Tomography Based Maxillary Sinus Imaging in Relation to Tooth Loss, Implant Placement and Potential Grafting Procedure

Spiral Computed Tomography Based Maxillary Sinus Imaging in Relation to Tooth Loss, Implant Placement and Potential Grafting Procedure

Spiral Computed Tomography Based Maxillary Sinus Imaging in Relation to Tooth Loss, Implant Placement and Potential Grafting Procedure

ABSTRACTObjectivesThe purpose of the present study was to explore the maxillary sinus anatomy, its variations and volume in patients with a need for maxillary implant placement.Material and MethodsMaxillary sinus data of 101 consecutive patients who underwent spiral computed tomography (CT) scans for preoperative implant planning in the maxilla at the Department of Periodontology, University Hospital, Catholic University of Leuven, Leuven, Belgium were retrospectively evaluated. The alveolar bone height was measured on serial cross-sectional images between alveolar crest and sinus floor, parallel to the tooth axis. In order to describe the size of the maxillary sinus anteroposterior (AP) and mediolateral (ML) diameters of the sinus were measured.ResultsThe results indicated that the alveolar bone height was significantly higher in the premolar regions in comparison to the molar region (n = 46, P < 0.01). The age showed negative relation to bone dimension (r = - 0.32, P = 0.04).Anterior and posterior border of the maxillary sinuses were mostly located in the first premolar (49%) and second molar (84%) regions, respectively. Maxillary sinus septa were indentified in 47% of the maxillary antra. Almost 2/3 (66%) of the patients showed major (> 4 mm) mucosal thickening mostly at the level of the sinus floor. The present sample did not allow revealing any significant difference (P > 0.05) in maxillary sinus dimensions for partially dentate and edentulous subjects.ConclusionsCross-sectional imaging can be used in order to obtain more accurate information on the morphology, variation, and the amount of maxillary bone adjacent to the maxillary sinus.

Spiral Computed Tomography Based Maxillary Sinus Imaging in Relation to Tooth Loss, Implant Placement and Potential Grafting Procedure

Objectives: The purpose of the present study was to explore the maxillary sinus anatomy, its variations and volume in patients with a need for maxillary implant placement.

Immediate Implant Placement Into Fresh Extraction Sites With Chronic Periapical Pathologic Features Combined With Plasma Rich in Growth Factors: Preliminary Results of Single-Cohort Study

The purpose of this prospective study was to evaluate the clinical outcome of implants immediately placed into fresh extraction sockets of teeth affected by chronic periapical pathologic findings, using plasma rich in growth factors (PRGFs) as an adjunct during the surgical procedure. A total of 30 partially edentulous patients with teeth requiring extraction and chronic periapical lesions were included in the present study. A total of 61 transmucosal implants were installed immediately after extraction and careful debridement combined with PRGF placement into the socket. Before insertion, the implant surface was bioactivated by humidification with liquid PRGFs. The prosthetic phase occurred 3 to 4 months after surgery. The implant success and survival and radiographic bone loss were evaluated after 1 year of function. Patient satisfaction for mastication function, phonetics, and esthetics was assessed using a questionnaire. Of the 61 implants, 1 had failed 2 months after insertion because of infection. No additional complications were recorded. The overall implant success and survival rate was 98.4% at 1 year of function. The mean follow-up was 18.5 months (range 10 to 21). All prostheses were successful. The peri-implant bone loss after 1 year averaged 0.41 +/- 0.22 mm. All patients reported full satisfaction for mastication function, phonetics, and esthetics. The use of PRGFs combined with an immediate implant placement procedure can be considered a safe, effective, and predictable treatment option for the rehabilitation of fresh postextraction infected sockets.

Interventions for replacing missing teeth: 1- versus 2-stage implant placement

Implants may be placed penetrating the oral mucosa (1-stage procedure) or can be completely buried under the oral mucosa (2-stage procedure) during the healing phase of the bone at the implant surface. With a 2-stage procedure the risk of having unwanted loading onto the implants is minimized, but a second minor surgical intervention is needed to connect the healing abutments and more time is needed prior to start the prosthetic phase because of the wound-healing period required in relation to the second surgical intervention. To evaluate whether a 1-stage implant placement procedure is as effective as a 2-stage procedure. The Cochrane Oral Health Group's Trials Register, CENTRAL, MEDLINE and EMBASE were searched. Handsearching included several dental journals. Authors of all identified trials, an Internet discussion group and 55 dental implant manufacturers were contacted to find unpublished randomised controlled trials (RCTs). The last electronic search was conducted on 21 January 2009. All RCTs of osseointegrated dental implants comparing the same dental implants placed according to 1- versus 2-stage procedures with a minimum follow up of 6 months after loading. Outcome measures were: prosthesis failures, implant failures, marginal bone level changes on intraoral radiographs, patient preference including aesthetics, aesthetics evaluated by dentists, and complications. Screening of eligible studies, assessment of the methodological quality of the trials and data extraction were conducted in duplicate and independently by two review authors. Authors were contacted for missing information. Results were expressed as random-effects models using mean differences for continuous outcomes and risk ratios for dichotomous outcomes with 95% confidence intervals. Five RCTs were identified and included reporting data on 239 patients in total. On a patient, rather than per implant basis, the meta-analyses showed no statistically significant differences for prosthesis and implant failures, though trends, especially in fully edentulous patients, favoured 2-stage (submerged) implants. The number of patients included in the trials was too small to draw definitive conclusions. The 1-stage approach might be preferable in partially edentulous patients since it avoids one surgical intervention and shortens treatment times, while a 2-stage submerged approach could be indicated when an implant has not obtained an optimal primary stability or when barriers are used for guided tissue regeneration, or when it is expected that removable temporary prostheses could transmit excessive forces on the penetrating abutments especially in fully edentulous patients.

Determination of the length of zygomatic implants through computed tomography: establishing a protocol

The aim of this study was to establish and verify an examination protocol using CT to estimate the length of zygomatic implants, thus rendering the surgical process safer and more predictable, and exposing the patient to a minimal level of radiation. Paracoronal CT scan was carried out on ten dry human crania (n = 20) and the zygomatic implant sites were measured (L(CT)) bilaterally. A standard surgical zygomatic implant placement procedure was carried out and the actual lengths (L(Real)) and clinical lengths (L(Clin)) determined. The averages of the L(CT), L(Clin) and L(Real) were 45.73 +/- 4.82 mm, 42.63 +/- 4.33 mm, and 44.73 +/- 4.53 mm, respectively. Student's t-test revealed no statistically significant differences between the L(Real) and L(CT) averages (P = 0.1532), whereas the L(Real) and L(Clin) averages were statistically different (P < 0.0001). The proposed protocol proved to be precise and efficacious in the determination of zygomatic implant length, with the advantage to the patient of a relatively low level of exposure to radiation due to the small quantity of tomographic slices used. Although there were no major repercussions, the clinical probe in the zygomatic implant kit commonly used in this surgical procedure proved to be a rather imprecise tool.

New Classification of Crown Forms and Gingival Characteristics in Taiwanese

Objectives:The aim of the investigation was to examine the forms of the crowns in the maxillary anterior tooth segment and corresponding gingival characteristics among healthy Taiwanese subjects.Materials and Methods:The crown width at the apical third (CW), length (CL), gingival angle (GA) and the interdental papilla height were assessed from the diagnostic stone model using a calibrated periodontal caliper. A CW/CL-ratio was calculated for each tooth and averaged for each tooth region. Gingival thickness (GT) and width of keratinized gingiva (WG) were measured clinically.Results:The cluster analysis revealed 3 classifications of crown forms: narrow (N), compound (C) and square (S) types. There was a significant difference among the 3 classifications with respect to CW/CL-ratio, GT, and WG (p < 0.0001).Conclusions:The results demonstrated varied crown forms and corresponding gingival characteristics in Caucasian and Taiwanese. The new classifications hinted that there was a polymorphism in different races and could be a valuable esthetic guideline and reference for anterior tooth rehabilitation, including various periodontal and restorative treatments and anterior implant placement procedures in Taiwanese.

A Prospective Multicenter Study Using Two Different Surgical Approaches in the Mandible with Turned Brånemark Implants: Conventional Loading Using Fixed Prostheses

The use of a submerged implant system in a nonsubmerged surgical procedure has been reported to have promising results. At the time this study was initiated, no prospective, comparative studies with randomization between submerged and nonsubmerged surgical techniques had been published. To evaluate the submerged and nonsubmerged surgical techniques when treating mandibular edentulism using a submerged implant system, with regard to implant survival and complications. A total of 77 patients were included and treated at nine clinics in Sweden and Norway. In total, 404 Brånemark System implants (standard and MkII implants) were inserted in the edentulous mandible; 198 implants according to the nonsubmerged protocol and 206 implants according to the traditional submerged procedure. The follow-up period was up to 36 months after prosthesis insertion. In the nonsubmerged group, 17 implants out of 198 implants (8.6%) were lost and in the submerged group, 5 out of 206 implants (2.4%) were lost. All implant failures occurred before the delivery of the final prosthesis. No major complications were reported during the implant surgery. However, at the clinical check-up postoperatively and at the abutment connection surgery, 6 patients in the nonsubmerged group complained of pain at the implant sites, whereas there were no complaints of pain in the submerged group. The results of this study suggest that a turned Brånemark implant designed for a submerged implant placement procedure can be used in a nonsubmerged procedure and may be as predictable as the conventional submerged approach.