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After extraction of 20 maxillary molar teeth, inter-radicular bone was intruded onto the sinus floor. Sinus perforation was occluded with oxidized cellulose. After 4 months of healing, implants were placed and later restored successfully. The technique increased vertical dimension about 4 mm on average and allowed placement of longer endosseous implants.
This clinical report describes the microscopic analysis of the postextraction bone response to bioactive glass particles used prior to titanium implant placement, after a healing period of 6 months. The clinical and radiographic follow-up were performed over a 3-year period after implantation.
STATEMENT OF PROBLEM: Masticatory forces acting on dental implants can result in undesirable stress in adjacent bone, which in turn can cause bone defects and the eventual failure of implants. PURPOSE: A mathematical simulation of stress distribution around implants was used to determine which length and diameter of implants would be best to dissipate stress. MATERIAL AND METHODS: Computations of stress arising in the implant bed were made with finite element analysis, using 3-dimensional computer models. The models simulated implants placed in vertical positions in the molar region of the mandible. A model simulating an implant with a diameter of 3.6 mm and lengths of 8 mm, 10 mm, 12 mm, 14 mm, 16 mm, 17 mm, and 18 mm was developed to investigate the influence of the length factor. The influence of different diameters was modeled using implants with a length of 12 mm and diameters of 2.9 mm, 3.6 mm, 4.2 mm, 5.0 mm, 5.5 mm, 6.0 mm, and 6.5 mm. The masticatory load was simulated using an average masticatory force in a natural direction, oblique to the occlusal plane. Values of von Mises equivalent stress at the implant-bone interface were computed using the finite element analysis for all variations. Values for the 3 most stressed elements of each variation were averaged and expressed in percent of values computed for reference (100%), which was the stress magnitude for the implant with a length of 12 mm and diameter of 3.6 mm. RESULTS: Maximum stress areas were located around the implant neck. The decrease in stress was the greatest (31.5%) for implants with a diameter ranging from of 3.6 mm to 4.2 mm. Further stress reduction for the 5.0-mm implant was only 16.4%. An increase in the implant length also led to a decrease in the maximum von Mises equivalent stress values; the influence of implant length, however, was not as pronounced as that of implant diameter. CONCLUSIONS: Within the limitations of this study, an increase in the implant diameter decreased the maximum von Mises equivalent stress around the implant neck more than an increase in the implant length, as a result of a more favorable distribution of the simulated masticatory forces applied in this study.
The purpose of this literature review is to present the outcomes of clinical studies on immediate and early loading protocols, identify shortcomings, and suggest a number of questions that still require exploration. English language clinical studies, limited to peer-reviewed journals between 1975 and 2004, were reviewed to identify treatment outcomes with these loading protocols. The data were tabulated from studies reporting on patients treated with fixed and overdenture prostheses. The former included partially edentulous patients treated with single or multi-unit prostheses. Within the limitations of this review, it can be concluded that these treatment protocols are predictable in the anterior mandible, irrespective of implant type, surface topography, and prosthesis design (success rates 90%-100%). Limited evidence for the edentulous maxilla (success rates 90%-100%) and the partially edentulous patient (success rates 93%-100%) are available, underscoring the need for further research. Studies suggest that to achieve predictable results in extraction sites, implant placement should be restricted to sites without a history of periodontal involvement (success rates 61%-100%). A number of questions require further exploration. There is a need to thoroughly investigate clinical outcomes to measure the economic benefit of these protocols and the impact of treatment on a patient's quality of life. Furthermore, more accurate long-term studies reporting on treatment protocols for separate clinical situations are required to allow meaningful comparisons.
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This article describes a comprehensive approach that enables the clinician to place dental implants, and fabricate a provisional prosthesis and a definitive metal-acrylic resin or metal-ceramic fixed complete denture in 3 appointments. This technique allows the practitioner to immediately load the implants with a provisional fixed complete denture at the time of implant placement, to record the relative positions of the implants and soft tissues, the occlusal vertical dimension, maxillomandibular relationship, and tooth position at the second appointment by using the information provided by the provisional fixed denture, and to insert the definitive prosthesis at the third appointment. This technique reduces chair time for both the patient and the clinician, and could ultimately reduce the cost of implant treatment and potentially increase treatment acceptance.
Platelet-rich fibrin (PRF) belongs to a new generation of platelet concentrates, with simplified processing and without biochemical blood handling. In this fourth article, investigation is made into the previously evaluated biology of PRF with the first established clinical results, to determine the potential fields of application for this biomaterial. The reasoning is structured around 4 fundamental events of cicatrization, namely, angiogenesis, immune control, circulating stem cells trapping, and wound-covering epithelialization. All of the known clinical applications of PRF highlight an accelerated tissue cicatrization due to the development of effective neovascularization, accelerated wound closing with fast cicatricial tissue remodelling, and nearly total absence of infectious events. This initial research therefore makes it possible to plan several future PRF applications, including plastic and bone surgery, provided that the real effects are evaluated both impartially and rigorously.
OBJECTIVE: To determine clinical success when implants are placed in chronic periapical infected sites. STUDY DESIGN: Fifty patients (25 females, 25 males, mean age 39.7 +/- 14.5 years) were included in this prospective controlled study. After randomization, 25 Frialit-2 Synchro implants were immediately placed (IP) after extraction, and 25 Frialit-2 Synchro implants were placed after a 3-month healing period (DP). Thirty-two implants were placed in the anterior maxilla and 18 implants were placed in the premolar region. Implant survival, mean Implant Stability Quotient (ISQ) values, gingival aesthetics, radiographic bone loss, and microbiologic characteristics of periapical lesions were evaluated for both groups. RESULTS: Overall, 2 implants belonging to the IP group were lost, resulting in a survival rate of 92% for IP implants versus 100% for DP implants. Mean ISQ, gingival aesthetics and radiographic bone resorption, and periapical cultures were not significantly different with the IP and DP implants. CONCLUSIONS: Immediate implant placement in chronic periapical lesions may be indicated.
Bone wound created in intramembranous alveolar bone heals without the formation of cartilage precursor tissue. However, the expression of cartilage collagen mRNAs has been suggested. In this report, we examined the expression and the potential role of type IX collagen in bone restoration and remodeling. The sequence specific polymerase chain reaction demonstrated the exclusive expression of short transcriptional isoform of alpha1(IX) collagen (Col9a1) in alveolar bone wound healing, while the long isoform of Col9a1 transcript was absent. Type IX collagen was immunolocalized in the preliminary matrix organized in granulation tissue before trabecular bone formation in tooth extraction socket. In Col9a1-null mutant mice, there were considerable variations in alveolar bone wound healing with the absence of or abnormally organized trabecular bone. Occasionally, unusual apposition of cortical-bone-like layers in bone marrow space was observed. The Col9a1-null mice indicated no growth retardation, and their facial and long bones maintained the normal size and shape. However, the primary spongiosa region of adult Col9a1 mutant mice showed an abnormal trabecular bone structure associated with abnormal immunostaining with the hypertrophic cartilage specific type X collagen antibody. These data suggest that type IX collagen short transcriptional variant is involved in the restoration and remodeling processes of trabecular bone.
The ovate pontic was initially described in 1933, but was only recently considered clinically acceptable. Historically, there has been resistance to ovate pontics, but this resistance lacks scientific and biologic evidence to justify rejection. Explicit instructions are mandatory for predictable results from dental laboratories. This article describes a method for communicating exact dimensions for an ovate pontic that was previously contoured for a patient in a provisional restoration to ensure clinical and histologic success. Polyvinyl siloxane putty is suggested as a matrix material for the predetermined contour. An esthetic and functional restoration will result when these materials and procedures are used in an appropriate sequence.
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Treatment philosophies in the management of alveolar clefts have changed greatly over the years. Currently. the most widely accepted protocol is for repair using autologous cancellous bone from the iliac crest during the stage of mixed dentition. Preliminary data suggest that the appropriate age for surgical repair during the secondary phase can be decreased without evidence of limitation of facial growth. Further long-term studies are necessary to support this protocol, however. With a multidisciplinary approach between the various medical and dental specialties, it is now commonplace to achieve normal dentofacial aesthetics and function. The continued advances in medical and dental technology have further contributed to the excellent outcomes that are now achieved.
OBJECTIVES: To compare preoperative radiological observations from dental panoramic tomographs (DPT), with surgical findings at removal of third molars with respect to the inferior alveolar nerve. STUDY DESIGN: One surgeon viewed the radiographs of 219 patients and recorded the radiological observations of the mandibular third molar tooth and the inferior alveolar nerve. The same surgeon removed the teeth and made detailed records of morphology of the root and its relation to the inferior alveolar nerve. Patients were reviewed postoperatively. RESULTS: A total of 300 teeth were removed and the neurovascular bundle was directly observed the root was grooved, or roots apices were deflected by the bundle in 35 (12%) cases. Postoperatively no patient had altered labial sensation. CONCLUSION: There was an intimate relation between the mandibular third molar tooth and the inferior alveolar nerve in 12 (51%) cases when darkening of the root was observed, and in only 11 (11%) cases when interruption of the radiopaque outline of the inferior alveolar neurovascular bundle was observed.
PURPOSE: This study evaluated the effectiveness of a protocol using platelet-rich plasma (PRP) to prevent bleeding after dental extraction in patients treated with anticoagulant oral therapy. MATERIALS AND METHODS: Forty patients with mechanical heart-value replacement who were treated with anticoagulant oral therapy were selected for the study. Each patient was treated with PRP gel placed into residual alveolar bone after extraction without heparin administration after suspension of oral anticoagulant drugs (36 hours). RESULTS: Only 2 patients reported hemorrhagic complications (5%). Sixteen patients (40%) had mild bleeding that was easy to control with hemostatic topical agents; this mild bleeding terminated completely 1 to 3 days after the surgical procedures. The remaining 22 patients (55%) presented with adequate hemostasis. CONCLUSIONS: Oral surgery in heart surgical patients under oral anticoagulant therapy may be facilitated with PRP gel. Its use is an advanced and safe procedure. This biological and therapeutical improvement can simplify systemic management and help avoid hemorrhagic and/or thromboembolic complications.
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OBJECTIVES: Healing after oral cavity surgery may be problematic in some cases, because it is a contaminated cavity. The purpose of this investigation was to evaluate the effect of fibrin glue on healing after surgical procedures in the oral cavity. METHODS: Forty-two Sprague-Dawley rats were used at this study, 24 in study (Group 1) and 18 in control (Group 2) groups. First molars of the rats were extracted with some cortical bone. The exposed cavities were filled with fibrin glue after hemostasis in study group but 5/0 silk suture was used in control group. The rats were sacrificed after two, four and six weeks and histologic analysis was performed. RESULTS: Healing was better in the study group. Foreign body reaction was lower in Group 1 (1/24, 4.1%) than Group 2 (6/18, 33.3%) (p<0.05). Also abcess formation scores were better in Group 1 (3/24, 12.5%) than Group 2 (10/18, 55.5%) (p<0.008, chi(2)=7). The last significant difference was on necrosis and better results were obtained in Group 1 (2/24, 8.3%) than Group 2 (10/18, 55.5%) (p<0.001, chi(2)=11.24). CONCLUSIONS: The use of fibrin glue on wound healing in the oral cavity has a positive effect when compared with traditional suture techniques.