Abstract: This paper describes the evolution of the concept of selecting the abutment at first-stage surgery and presents clinical data accumulated over 14 years of the use of this concept with angulated abutments. The concept was developed for implants using internal and external hexed connections and has evolved in its use for implants using a Morse taper connection as a result of the considerable clinical advantages that this type of connection offers. A total of 3101 implants were restored using angled abutments ranging from 0 to 45 degrees and were observed over a period of up to 151 months. After an observation time of 120 months (10 years) after placement, the calculated 95% confidence interval of the mean survival estimation, according to Aalen et al, was 98.2% (+/- 0.7%). The magnitude of the angles did not influence the survival rate. The need to refine the implant position in terms of the depth to which it was placed and the angulation and rotational orientation, as well as the size and pivot point of the final abutment, were recognized as contributing to the harmonious emergence profile of the restoration. Good esthetic and functional outcomes were achieved by the use of conventional cement-retained restorations made possible by parallel and aligned abutments.

Abstract: Untreated dental bone defects usually lead to resorption of alveolar bone. Filling these defects with bone substitute material prevents resorption of bone, preserves the alveolar ridge, and provides sufficient bone for immediate or subsequent implant placement. A variety of bone substitutes is available. They differ in origin, consistency, particle size, porosity, and resorption characteristics. We have treated almost 1000 bony defect sites in 267 patients with the bone regeneration material Cerasorb. Being resorbed simultaneously with the formation of new bone, it is completely replaced by the patient's own vital bone within 6 to 12 months. The representative cases described in this paper demonstrate the successful use of the pure-phase beta-tricalcium phosphate ceramic in the treatment of all dental bone defects.

Abstract: The high success rate of dental implants has changed the quality of life for many patients. Immediate loading finds its application in some clinical cases and certainly adds another modality of treatment for the implant patient. Starting with a couple of implants placed in the mandible and immediately loaded within 72 hours after surgical placement with an overdenture, this concept evolved to immediately loading multiple implants in both the maxilla and the mandible. In this investigation, 11 consecutive patients were treated with 87 screw-shaped endosteal acid-etched, Osseotite implants (3i, Implant Innovations, Inc., Palm Beach Gardens, FL) between June 1998 and June 1999. Two mandibular and two maxillary cases received screw-retained provisional prostheses the day of surgery. Three mandibular and four maxillary cases were loaded 48 hours after surgery with the final screw-retained, porcelain-fused-to-metal prostheses. All implants were followed for 2 to 3 years. Follow-up consisted of clinical as well as radiographic examination. All implants were successful. There was no implant mobility or periimplant radiolucency. The bone level was measured at the 12th and 24th months. The average radiographic bone level from the implant platform to the first bone-to-implant contact was 0.654 mm at the 12th month and 0.946 mm at the 24th month. We conclude that a high success rate can be achieved when implants with a hybrid surface, machined/acid-etched, are immediately loaded within 48 hours after surgical placement in the maxilla and the mandible.

Abstract: The successful maintenance of crestal bone surrounding dental implants is imperative for long-term implant success. Crestal bone loss is reportedly related to stress. However, early perforation and partial exposure of the implant’s covering device are a focus for plaque accumulation, which, if left untreated, may result in inflammation. The objective of this study was to evaluate the crestal bone levels adjacent to submerged and exposed unloaded dental implants during the initial healing phase. In addition, the microbiota around exposed implants were studied. Bilateral implants were placed in the mandible of 10 patients. In one quadrant, the implants were covered by the flap. In the other quadrant, the flap was sutured, leaving the cover screws completely exposed. Standardized periapical radiographs were obtained at implant placement and 4 months later. Radiographs were digitalized, aligned, and analyzed with a computer-assisted method. Cultures were obtained from exposed implant sites. All patients showed more crestal bone loss around exposed dental implants compared to submerged implants. Prevotella sp., Streptococcus beta-hemoliticus, and Fusobacterium sp. were the microorganisms identified in most of the sites. The exposure of the implant covering device created foci for bacterial plaque accumulation, which may have facilitated periimplant crestal bone loss. The initial healing phase follow-up may be critical for implant success.

Abstract: The purpose of this study was to compare the in vitro strains on dental implants supporting cement-retained fixed partial dentures under axial and off-axial loading conditions. Ten implants incorporating strain gauges were placed in a certain configuration to simulate different clinical situations and were embedded in an experimental model. Two implant supported three-unit fixed partial dentures were fabricated on four groups of implants, and each group consisted of seven restorations. The prostheses were cemented with a temporary cement. Fifty N vertical load was applied on predetermined axial and off-axial loading locations on the prostheses. Strain indicator readings were recorded at a standardized time following each loading sequence. The point of load transfer affected strains on implants. For all prosthetic designs, off-axial loading generated more strain than axial loading on implants (P < 0.05). In comparison with axial loading, off-axial loading causes bending of the implants that may affect bone loss around the implant collar. Axial loading of implants should be provided by using wide diameter implants, narrow occlusal tables, and proper occlusal contacts on implant restorations.

Abstract: The predictability of implant fixtures as a long-term solution for edentulous areas has improved to the point where they have become the standard of care in many situations, in lieu of fixed prostheses. At the same time, the success rate of endodontically treated teeth, and those requiring retreatment, is very high as well. The dilemma presented to the clinician in treatment planning is when to retreat a tooth or extract and place an endosseous root-form implant. Risk assessment for prognostic evaluation plays an important role in the decision-making process. The clinical and systemic factors affecting the longevity of a tooth need be considered as well as location, bone quality and amount, and the condition of the patient's other teeth. This article attempts to provide a meaningful algorithm that will provide a basis for an appropriate choice of therapy.

Abstract: A buccal plate destroyed as a result of a longitudinal root fracture was completely restored by the use of a Frialit-2 implant placed in the alveolus of the fractured maxillary left first bicuspid. An acellular dermal matrix material was used as a membrane barrier to cover the implant, and a bioactive glass was used as grafting material. After 6 months, the defect around the implant was completely filled by mineralized tissue.

Abstract: Periodontium in normal dentition is not as it is surrounding an implant area. Thus, periodontal probing with normal dentition is not similar to periimplant probing. The periimplant probing protocol should be different from periodontal probing because of inherent anatomical differences. The aim of this paper is to review the topics related to periimplant probing and to draw inferences to develop a periimplant probing protocol.

Abstract: Purpose The purpose of this study was to conduct a comparative immunohistochemical evaluation of microvessel density (MVD) in alveolar sites augmented with autologous bone or Bio-Oss. Materials and methods Eighteen patients participated in this study. All patients presented maxillary ridge defects. These defects were filled in a random fashion with autologous bone or Bio-Oss. Endosseous implants were inserted after a mean of 3 months in the sites augmented with autologous bone and after a mean of 6 months in the sites augmented with Bio-Oss. As part of the implant site preparation, a trephine was used to harvest bone cores. As control, bone cores retrieved in nonaugmented sites were used. The mean value of MVD in control bone was 25.6 +/- 3.425. In the sites augmented with autologous bone, the MVD was 29.8 +/- 4.4, while in the sites regenerated with Bio-Oss, the MVD was 29.7 +/- 2.4. The statistical analysis showed that the difference in MVD between control bone and autologous bone (P = 0.057) and between control bone and Bio-Oss (P = 0.023) was statistically significant. The difference between the sites regenerated with autologous bone and those regenerated with Bio-Oss was not significant (P = 0.6889). Conclusions Our results show that both sites augmented with autologous bone and Bio-Oss presented a higher and statistically significant quantity of microvessels compared with control specimens. No significant differences were found when comparing the MVD of the sites regenerated with autologous bone and those regenerated with Bio-Oss. The retrieval time was, however, a mean of 3 months for the autologous bone sites and a mean of 6 months for the Bio-Oss sites. These data could support the hypothesis of faster healing for the sites augmented with autologous bone.

Abstract: Accurate radiographic assessment of available bone dimension superior to the mandibular canal is essential to the favorable placement of dental implants. Panoramic and periapical radiography are the standard of care. They typically offer a clinically adequate interpretation of the canal topography.

Abstract: BACKGROUND The predictability and success of endosseous dental implants has secured their place as a standard treatment modality. Nevertheless, a small number of implants will fail regardless of operator experience or clinically recognizable cause. This article presents two cases of early failure of two-stage dental implants manifesting in a spontaneous and rapid exfoliation. METHODS Two healthy adult male patients received single-tooth, machined titanium implant fixtures during uncomplicated stage-one surgical procedures. RESULTS After an uneventful early postoperative healing phase, both patients returned during the 4 to 6 week time period with failing implants. Clinical examination in both cases revealed the exfoliation of a fixture from the edentulous area with varying signs of soft tissue reaction in each instance. Radiographs revealed osteotomy sites along with the coronally migrating fixtures, with one of the exfoliated implants accompanied by apparent perifixtural radiolucency. In both cases, the implant fixtures were removed digitally without anesthesia. Subsequent medical follow-up was noncontributory, and ultimate healing was uneventful in both cases. Two separate attempts in the mandibular right second premolar region of one patient ended in similar failures despite the successful osseointegration of an identical fixture on the contralateral side. CONCLUSIONS Few cases of early exfoliation of dental implants have been reported in the literature. Although the exact etiology of the early fixture loss in these two patients is unclear, the description of these cases can add to the published knowledge of dental implant failures and potentially lead to the uncovering and prevention of their causative mechanisms.

Abstract: This study investigated the designs of osseointegrated prostheses in cases of free-end partial edentulism using comparative stress interpreted with the three-dimensional finite element method. Three free-end fixed osseointegrated prostheses models with various connection designs (i.e., rigidly connected to an abutment tooth and an implant, rigidly connected to an implant and two abutment teeth, and rigidly connected to an implant and three abutment teeth) were studied. The stress values of the three models loaded with vertical, buccolingual, and linguobuccal directions at 30 degrees angled to vertical axis forces were analyzed. When the fixed partial denture was connected to the three natural abutment teeth and an implant, the lowest levels of stress in the bone were noted.

Abstract: This study investigated the influence of nicotine on bone density around titanium implants inserted in rabbits. Thirty-two New Zealand rabbits were included. After anesthesia, the tibiae surfaces were exposed and two screw-shaped, commercially available, pure titanium implants of 7.0 mm in length and 3.75 mm in diameter were placed bilaterally. A total of 128 implants were inserted: 64 blasted with Al2O3 particles (group 1) and 64 with a machined surface finish (group 2). The animals were randomly assigned to one of four treatment subgroups, and daily subcutaneous injections of nicotine were administered. After 42 days, the animals were killed and undecalcified sections were prepared. The bone density was measured in the cortical passage of the implant. Statistical analysis (two-way analysis of variance) revealed no significant difference neither regarding the effect of nicotine nor the effect of surface design on bone density around the implants (P > 0.05). Within the limits of the present study, it can be assumed that daily nicotine administration may not statistically influence bone density around titanium implants.

Abstract: Understanding the principles of occlusion as they relate to managing bite forces on implants is extremely important to maintain the longevity of dental implant prostheses. Specifically, altering vertical dimension of occlusion (VDO) scientifically and predictably is critical to the creation of proper tooth form and guidance when fabricating a full-arch implant-supported prosthesis.

Abstract: A maxillary sinus augmentation graft floor can increase vertical bone height for implant placement in patients with a pneumatized sinus. A simple technique can make this routine procedure even more predictable. After the sinus membrane has been adequately reflected, a cottonoid soaked with 1 carpule of 2% Lidocaine with 1:100,000 epinephrine and left in place for 5 to 15 minutes in each maxillary sinus can help create vasoconstriction and hemostasis. By arresting the oozing type of bleeding from the sinus membrane and the floor of the maxillary sinus, the cottonoid technique enhances direct visualization of the sinus and sinus membrane, further reflects the sinus membrane bluntly and gently with minimal risk of a membrane perforation, and serves as a volume indicator to assess the graft volume required.

Abstract: A technique is presented for placement of implants at the time of tooth extraction in the precisely desired positions, regardless of extraction socket morphology. To date, 162 implants have been placed utilizing this technique. One was mobile at uncovery and removed. The other implants have been successfully in function, as defined by the Albrektsson Criteria, for up to 7 years, yielding a cumulative success rate of 99.4%.

Abstract: This paper demonstrates how a computer software program was utilized in a private practice to supplement the clinical evaluation of one implant system. Clinical data were entered into a computer database at the time of implant placement and up to 13 years for follow-up appointments. Data were divided into two groups and subjected to lifetable analyses. The focus group consisted of a machined-titanium, screw-type implant with an internal abutment connection from one manufacturer. The residual database consisted of mixed implant designs with a variety of abutment connections and surfaces from several other manufacturers. Lifetable survival data between the two groups were generated. Cumulative survival rates from 0 to 13 years were 94.2% (n = 435) for the focus group and 90.1% (n = 2339) for the reference group. There were 25 implants lost in the focus group and 11 other implants were deemed "at risk." Survival results from other lifetable analyses are also presented for the two groups. Documentation of empirical clinical data in a computer software database over a period of time can help private practice clinicians better evaluate the dental implant systems used in their practices.

Abstract: A primary goal in the reconstruction of the dental implant patient is to achieve the lowest stress possible on the abutments, both artificial and natural. Bidez and Misch use the formula [figure: see text] [formula: see text] to explain that the stress can be easily lowered by increasing "A," by using larger implants, or by using additional implants. Another equally important method of lowering the stress is to reduce and manage the force application (F). The majority of completed implant cases can well tolerate applied forces from mastication and swallowing, both of which are close to 50 pounds per square inch, but it is the destructive power from DCS that can easily range from 500 to 1,000 pounds per square inch with which this article is concerned.

Abstract: Implant survival in poor-quality bone continues to pose a significant clinical challenge to dentists. The SwissPlus System comprises one-piece, straight and tapered implant designs with self-tapping, apical threads, and a microtextured surface on the intraosseous portion of the implant bodies. Although both designs are indicated for all ranges of bone density, Tapered SwissPlus features double-lead threads and a soft-bone surgical protocol designed to enhance initial mechanical stability at the time of placement. This paper presents an overview of the SwissPlus System with emphasis on the surgical aspects. Presented test data also illustrate intersystem compatibility and differences between the straight SwissPlus and ITI synOcta implants.

Abstract: The immediate restoration or loading of dental implants has been an intense area of clinical trial and research in the field of dental implantology over the last several years. The ability to temporize implants that are placed and prevent the use of a removable transitional appliance is appealing to not only patients, but dentists as well. Additionally, the placement of implants into immediate extraction sockets, and the immediate restoration of those implants, is showing excellent success rates clinically. Enhancement of the healing phase using platelet rich plasma seems to be a key contributor to the healing and maturation rate of both the hard and soft tissues. This article will review the immediate restoration of implants placed into multiple extraction sockets and the use of platelet rich plasma to enhance the healing phase.