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Background: The innervation of skin and oral mucosa plays a major physiological role in exteroception. This innervation is also clinically relevant as sensory changes occur after neurosurgical procedures. Purpose: The goal of this study was to compare the perception of mechanical stimuli applied to the buccal mucosa in the vicinity of osseointegrated oral implants with that in the controlateral dentate side. The role of the previously reported increased innervation in the peri-implant soft tissues in the oral sensorimotor function was thus examined. Materials and Methods: Seventeen subjects with 20 implants were tested. Directional cutaneous kinaesthesia (DCK) and graphesthesia (G) were performed on the buccal side of the alveolar mucosa before and at planned intervals after implant placement. The observation was pursued until 6 months after the prosthetic rehabilitation. In each subject, the contralateral mucosa served as a control to the implant sites. Average percentages of correct responses in a four-choice task for DCK and a three-choice task for G were calculated. Results: Despite an intersubject variation in both the DCK and G, high intraindividual correlations were found (p < .005). The implant sites showed a significant difference toward the control sites at the four interval test for both tests. For DCK and G, the average of correct responses decreased after abutment connection (i.e., after the implant uncovering surgery) to increase afterwards to reach a level close to, but still lower than, the control sites 3 to 6 months after the prosthetic rehabilitation. Conclusion: The DCK and G are simple but reliable sensory tests that can be easily applied in the oral region. This prospective study indicates that tooth loss reduces tactile function compared with implant-supported prostheses. The peri-implant soft tissues could be partially involved in the osseoperception function.

Purpose: The aim of this report is to quantitatively and qualitatively describe the bone tissue response to Branemark implants retrieved from grafted sites in patients. Materials and Method: The material consists of consecutively received Branemark implants retrieved from grafted sites. Thirty-five of these implants, retrieved from 16 patients, were suitable for the histologic evaluation of undecalcified sections in the light microscope. Results: The unloaded implants were mainly lined with soft tissue, and sparse bone-implant contact was observed only in some sections. The loaded implants, with the exception of one implant removed due to mobility, had mature and new bone-implant contact. Resorption of graft through cutting cone structures was detected. Cement lines were found separating bone-like tissue albeit no cellular content and bone tissue with detectable osteocytes. Conclusion: In this heterogeneous group of implants from grafted sites, the unloaded implants showed limited bone-implant contact. The autografts showed seemingly mixed viability as judged by the cell content in the osteocyte lacunae and cement lines separating areas with filled and empty lacunae.

Background: Based on three-dimensional implant planning software for computed tomographic (CT) scan data, customized surgical templates and final dental prostheses could be designed to ensure high precision transfer of the implant treatment planning to the operative field and an immediate rigid splinting of the installed implants, respectively. Purpose: The aim of the present study was to (1) evaluate a concept including a treatment planning procedure based on CT scan images and a prefabricated fixed prosthetic reconstruction for immediate function in upper jaws using a flapless surgical technique and (2) validate the universality of this concept in a prospective multicenter clinical study. Materials and Methods: Twenty-seven consecutive patients with edentulous maxillae were included. Treatments were performed according to the Teeth-in-an-Hour™ concept (Nobel Biocare AB, Goteborg, Sweden), which includes a CT scan-derived customized surgical template for flapless surgery and a prefabricated prosthetic suprastructure. Results: All patients received their final prosthetic restoration immediately after implant placement, that is, both the surgery and the prosthesis insertion were completed within approximately 1 hour. In the 24 patients followed for 1 year, all prostheses and individual implants were recorded as stable. Conclusion: The present prospective multicenter study indicates that the prefabrication, on the basis of models derived from three-dimensional oral implant planning software, of both surgical templates for flapless surgery and dental pros-theses for immediate loading is a very reliable treatment option. It is evident that the same approach could be used for staged surgery and in partial edentulism.

Background: The anterior mandible is generally considered a rather safe surgical area, involving few risks of damage to vital anatomic structures. Nevertheless, both neurosensory disturbances and hemorrhages have been reported after implant surgery in that particular area. Purpose: With the increasing demand for oral implant placement, the anatomy of the anterior mandible should receive more attention. This review will focus on the anatomic peculiarities of the anterior mandible and the related clinical implications. Methods: The scientific evidence on the anatomic, histologic, physiologic, and clinical aspects of the neurovascularization of the anterior mandible will be reviewed. Results: Surgical complications may be attributed to the existence of a mandibular incisive canal with a true neurovascular supply. Potential risks may also be related to the presence of the lingual foramen and anatomic variations, such as an anterior looping of the mental nerve. Conclusions: Preoperative radiographic planning for oral implant placement in the anterior mandible should therefore not only consider all esthetic and functional demands but should also pay particular attention to the anatomic peculiarities of this region to avoid any neurovascular complications.

Background: During recent years a new treatment concept, Branemark Novum, has been developed in which implants are inserted in the edentulous lower jaw and immediately connected to a prefabricated titanium bar. A fixed prosthesis is then attached to the bar during or immediately following surgery. Purpose: The aim of the present study was to investigate the application of this concept under various settings, to determine technique sensitivity, and to evaluate the clinical outcome after 1 year of follow-up. Materials and Methods: Fifty-one patients were included in a prospective multicenter investigation and followed up for 1 year. Cumulative implant survival rates were evaluated by life table analysis. In addition, clinical comparisons were performed to evaluate implant loss in relation to patient characteristics. Questionnaires were used to evaluate the treatment protocols and to obtain patients' opinions. Results: The prosthetic treatment was completed on the same or the following day in 76% of the patients. The cumulative implant survival rates for implants and prostheses were 91% and 94%, respectively, after 12 months. Conclusions: The present study demonstrated that single-stage surgery and immediate loading of implants with prefabricated bridgework in the mandible can result in high implant success and significant reduction in treatment time, with patient satisfaction.

Background: As the use of oral implants for the treatment of partially as well as fully edentulous patients has increased the past two decades, more specialized radiographie techniques have become available for the preoperative planning of oral implant placement. Purpose: The goal of this article was to enable clinicians to select the appropriate imaging techniques when planning for oral implants. Materials and Methods: This article reviews the available literature about various imaging techniques and their indication for the preoperative planning of oral implants. The advantages and drawbacks of each technique are described. A dosimet-ric overview is given relative to different radiologie techniques used in various clinical situations. Results: For preoperative planning of implant placement, advantages and drawbacks of the available imaging techniques have been considered, which allows guidelines for image technique selection to be formulated based on the clinical situation provided, considering the diagnostic yield of each technique and the radiation doses involved. Conclusions: From the available literature, it can be stated that many clinical situations demand the use of cross-sectional imaging techniques for optimal preoperative planning of implant placement. Nevertheless, such techniques are not required in cases in which the clinical examination reveals sufficient bone width and where standard radiographie examinations, such as intraoral and panoramic radiography, reveal adequate bone height and space for implant placement.

Background: Barrier membranes have been used to promote bone ingrowth on implants with dehiscences and fenestrations. Membranes also have been used to protect defects adjacent to implants placed at the time of extraction. The concept of guided bone regeneration relates to preferentially allowing cells from bone to migrate into various defects while excluding fibrous tissue and epithelium. The purpose of these procedures is to enhance bone-to-implant contact at the treated sites and to prevent mucosal complications. Purpose: The purpose of this article is to report clinical outcomes for implants placed at the time of extraction and augmented with expanded polytetrafluoroethylene (ePTFE) and followed for 5 years. The outcomes for implants with dehiscences and fenestrations augmented with ePTFE barriers and followed up to 5 years also are reported. Methods and Materials: Four treatment centers participated in this study (Tucson, Gothenburg, Spokane, and Leuven). In the extraction group, teeth were removed for varying reasons, and Branemark implants were placed and stabilized within the host bone. Defects present at the coronal implant aspect were covered with ePTFE barrier membranes. Flaps were rotated to cover the membrane-treated sites. If exposure of the material occurred prior to second-stage surgery, the membranes were removed. Barriers remaining unexposed were removed at second-stage surgery. The implants were followed up to 5 years. In the fenestration and dehiscence group, implants with exposed threads were augmented with ePTFE barrier membranes. The barriers were removed at appropriate intervals, and the patients were followed up to 5 years. Radiographic measurements were made from nonstandardized periapical radiographs at abutment connection and 1, 3, and 5-year follow-up visits. Results: Forty patients participated in the extraction group. They received a total of 49 implants. Three implants failed prior to loading. The 5-year cumulative survival rates for implants placed at the time of extraction were 93.9% and 93.8%, respectively, for maxillary and mandibular implants. The average maxillary mesial and distal marginal bone loss (1–5 yr) was 0.3 mm (standard deviation [SD] = 1.5) and 0.3 mm (SD = 1.0). In mandibles, the average mesial and distal bone loss (1–5 yr) was -0.2 mm (SD = 0.5) and -0.05 mm (SD = 0.6), respectively. The dehiscence and fenestration group included 44 patients. Twenty-six were followed for up to 5 years. Eight patients experienced total implant failure. For dehiscences and fenestrations, the cumulative survival rates were 76.8% and 83.8% for maxillary and mandibular implants, respectively. The average maxillary mesial and distal bone loss (1–5 yr) was 0.4 mm (SD = 0.8) and 0.2 mm (SD = 0.9), respectively. In mandibles, the average mesial and distal marginal bone loss was 0.3 mm (SD = 0.9) and 0.3 mm (SD = 0.8), respectively. Conclusions: Implants placed at the time of extraction and augmented with ePTFE barrier membranes have favorable long-term predictability. On the other hand, long-term evaluation of implant dehiscences and fenestrations augmented with barrier membranes indicates that they have less favorable 5-year survival rates. Membrane augmentation of these may be questioned.

The innervation of skin and oral mucosa plays a major physiological role in exteroception. This innervation is also clinically relevant as sensory changes occur after neurosurgical procedures.The goal of this study was to compare the perception of mechanical stimuli applied to the buccal mucosa in the vicinity of osseointegrated oral implants with that in the controlateral dentate side. The role of the previously reported increased innervation in the peri-implant soft tissues in the oral sensorimotor function was thus examined.Seventeen subjects with 20 implants were tested. Directional cutaneous kinaesthesia (DCK) and graphesthesia (G) were performed on the buccal side of the alveolar mucosa before and at planned intervals after implant placement. The observation was pursued until 6 months after the prosthetic rehabilitation. In each subject, the contralateral mucosa served as a control to the implant sites. Average percentages of correct responses in a four-choice task for DCK and a three-choice task for G were calculated.Despite an intersubject variation in both the DCK and G, high intraindividual correlations were found (p.005). The implant sites showed a significant difference toward the control sites at the four interval test for both tests. For DCK and G, the average of correct responses decreased after abutment connection (i.e., after the implant uncovering surgery) to increase afterwards to reach a level close to, but still lower than, the control sites 3 to 6 months after the prosthetic rehabilitation.The DCK and G are simple but reliable sensory tests that can be easily applied in the oral region. This prospective study indicates that tooth loss reduces tactile function compared with implant-supported prostheses. The peri-implant soft tissues could be partially involved in the osseoperception function.

The aim of this report is to quantitatively and qualitatively describe the bone tissue response to Brånemark implants retrieved from grafted sites in patients.The material consists of consecutively received Brånemark implants retrieved from grafted sites. Thirty-five of these implants, retrieved from 16 patients, were suitable for the histologic evaluation of undecalcified sections in the light microscope.The unloaded implants were mainly lined with soft tissue, and sparse bone-implant contact was observed only in some sections. The loaded implants, with the exception of one implant removed due to mobility, had mature and new bone-implant contact. Resorption of graft through cutting cone structures was detected. Cement lines were found separating bone-like tissue albeit no cellular content and bone tissue with detectable osteocytes.In this heterogeneous group of implants from grafted sites, the unloaded implants showed limited bone-implant contact. The autografts showed seemingly mixed viability as judged by the cell content in the osteocyte lacunae and cement lines separating areas with filled and empty lacunae.

Background: The innervation of skin and oral mucosa plays a major physiologic role in exteroception. It is also of interest clinically, as illustrated by sensory changes after neurosurgical procedures. Purpose: The goal of this study was to assess the perception of mechanical stimuli applied to the anterior maxilla in denture wearers and subjects rehabilitated with osseointegrated implants compared with that in subjects with a natural dentition. Materials and Methods: Five groups of subjects were selected and tested in the maxillary region only. Test groups included patients with a complete denture, an implant-supported fixed prosthesis (full or partial), or a single-tooth replacement. Light-touch sensation and two-point discrimination were performed on the buccal side of the alveolar mucosa and vibrotactile function was determined for natural teeth, full dentures, or implant-supported prostheses. Results: For light-touch sensation, no significant differences could be found between the groups. For two-point discrimination, full-denture patients showed higher threshold levels than the other groups. The threshold levels for vibrotactile function were higher in both full dentures and implant-supported prostheses compared with natural dentitions. Conclusion: Natural dentitions offer superior vibrotactile function compared to any other dental status. Full dentures often show a stronger deterioration of the (vibro)tactile function compared with implant-supported prostheses.

Background: The original protocol or Branemark to achieve predictable osseointegration for oral implants has substantially been modified. One may question whether results are influenced by those modifications, especially for the longterm prognosis. Purpose: The goal of the present study was to investigate the impact of those parameters that deviate from the original protocol as defined by P-I Branemark. Materials and Methods: In this study, 246 patients with 263 fixed partial prostheses supported by 668 Branemark implants were followed from 1 to 15 years (mean:6.3 yr). Radiographs were taken at the time of abutment connection, at 3 to 6 months, at 12 months, and then every 3 years. The bone level was rated mesially and distally from the implants on a total of 2588 radiographs. Results: A positive relation between abutment length and marginal bone level was found (p >.0001). The maxilla (p =.03), porcelain (p =.007), long abutments (p =.008), and regular-sized diameter implants (p =.001) all exhibited more bone loss in the first 6 months. After 6 months, only long implants showed more bone loss (p =.03). Conclusions: Overall, the marginal bone level remained stable around Branemark implants, never surpassing 2.2 mm, even after 15 years. Although longer implants lost more bone over time, this has to be interpreted with respect to higher resorption rates in less resorbed jaws.

Background: The replacement of a single tooth or several teeth by means of single-implant restorations is an increasingly used method that needs long-term validation. Purpose: The goal of this study was to evaluate the outcome of single-implant restorations by means of fixed restorations and to define the prognosis through marginal bone level estimations. Materials and Methods: From November 1986 to June 1998, 270 Branemark implants (215 in the upper jaw) were installed in 219 patients (106 males). Both anterior and posterior sites were involved. Of the 263 single restorations, 28 were placed in private dental offices. The patients were followed until June 1999. Results: Twelve implants failed before or at abutment connection or within 6 months afterward. Only four implants failed later. The cumulative success rates were 93% for the implants and 96.5% for the restorations over a period of 11 years. The marginal bone loss during the first 6 months after abutment connection reached 0.71 mm and then dropped to 0.036 mm annually over a period of 10 years. Conclusions: Single-implant restorations (Branemark System) are a reliable treatment with a good long-term prognosis. Failures were concentrated during the healing period and early loading phase.