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Biomedical subjects

M Davarpanah

Publications and source records attributed to M Davarpanah.

At least 19 recordsLinked to original sources

Optimal implant stabilization in low density bone.

Initial stability of the implant is one of the fundamental criteria for obtaining osseointegration. An adequate primary anchorage is often difficult to achieve in low density bone (type IV). Various surgical suggestions were advanced in the 1980s which were aimed at achieving optimal osseous integration in poor quality bone. They offered satisfactory short-term results. Recently, as a result of surgical and technological innovations, new therapeutic proposals have shown very interesting results in their initial studies.

Bone Density↗

Osseotite implant: 3-year prospective multicenter evaluation.

PURPOSE: This prospective multicenter study evaluates the cumulative success rate of the Osseotite implant after 3 years of prosthetic loading. MATERIALS AND METHODS: A total of 413 Osseotite implants (Implant Innovations) were placed in 142 patients (completely or partially edentulous) in five dental offices exclusively devoted to implants. The average age of the patients was 58.3 years. Of the 413 implants, 191 were placed in the maxilla and 222 in the mandible; 271 (65.6%) were posterior implants and 142 (34.4%) were anterior implants. Clinical and radiographic evaluations were made after completion of the prosthetic restoration, after 6 months of loading, at 1 year, and at 3 years. RESULTS: A cumulative success rate of 95.3% was obtained after 3 years of prosthetic loading. The success rate was similar in both arches: 95.1% in the maxilla and 96.8% in the mandible. Early failures (before prosthetic loading) were greater (n = 12) than late failures (n = 2). After 3 years of prosthetic loading, the marginal bone level of 385 (93.2%) implants were evaluated radiographically. Bone level was at the first thread for 91.4% of the implants. A slightly increased loss was observed around 26 implants (6.7%). Including survival implants, the cumulative implant success rate after 3 years was 96%. A success rate of 98.4% was obtained with 187 short implants (8, 5 and 10 mm) reported in this multicenter evaluation. CONCLUSION: This multicenter evaluation demonstrates excellent predictability for Osseotite implants.

Adult↗

The modified osteotome technique.

Patients who have been partially edentulous in the posterior segments for many years frequently present with reduced alveolar bone and/or enlarged sinuses. The choice of treatment for these patients will depend on the volume of residual bone, morphology of the alveolar crest, and amount of space available for the prosthesis. A new, minimally invasive surgical procedure using Summers osteotomes is described for the treatment of the edentulous posterior maxilla in which the bone thickness below the sinus is limited (> or = 5 mm). This suggested modified treatment is based on the use of a combination of osteotomes, drills, and screw-type implants with a rough surface texture.

Bone Transplantation↗

Wide-diameter implants: new concepts.

At the end of the 1980s, it was suggested that wide-diameter implants be used to better the prognosis in cases in which the condition of the supporting bone is unfavorable. Technical improvements associated with different shapes and materials used for implants have led to an evolution of our concepts of surgical and prosthetic treatments. The aim of these new suggestions is to optimize the functional and esthetic result while respecting the fundamental principles of osseointegration. Up to the present time, very few studies have been published on wide-diameter implants. However, the short- and medium-term results that have been reported have been very satisfactory.

Biocompatible Materials↗

Small-diameter implants: indications and contraindications.

The choice of implant diameter depends on the type of edentulousness, the volume of the residual bone, the amount of space available for the prosthetic reconstruction, the emergence profile, and the type of occlusion. Small-diameter implants are indicated in specific clinical situations, for example, where there is reduced interradicular bone or a thin alveolar crest, and for the replacement of teeth with small cervical diameter. Before using a small-diameter implant, the biomechanical risk factors must be carefully analyzed. Preliminary reports of this type of implant show good short- and medium-term results.

Alveolar Bone Loss↗

To conserve or implant: which choice of therapy?

The longevity of teeth depends directly on the state of the periodontal tissues. Many etiologic factors can lead to the loss of a tooth. Tooth loss is frequently associated with bone resorption. The diagnosis of a condition and knowledge of its etiology are essential to assess the prognosis of the remaining teeth and to formulate the correct treatment plan. Many parameters must be investigated to ascertain an accurate diagnosis. An understanding of the patient's needs and the length and likely success of treatment guides the decision of whether to preserve teeth or extract them and place implants. Advanced periodontitis poses a major therapeutic dilemma. Judicious, strategic extractions may permit the placement of long implants in ideal positions.

Alveolar Bone Loss↗

Implant treatment of posterior mandibular sextants.

In mandibular posterior sextants an insufficient bone quality or volume may contraindicate implant placement. Crestal bone resorption, supra-eruption of teeth, and minimal bone coronal to the mandibular canal are the principal reasons for not placing dental implants. The available prosthetic space is also a major factor in determining surgical and prosthetic treatment. Various surgical approaches are used to create adequate bone volume in the posterior mandible, thereby allowing the possibility for implant placement. The therapeutic choice is made depending upon residual bone volume and available prosthetic space. The risks and disadvantages of the various techniques must be seriously evaluated and explained to the patient.

Alveolar Bone Loss↗

Restorative and periodontal considerations of short clinical crowns.

The purpose of this review was to examine the periodontal and restorative factors related to restoring teeth with short clinical crowns. Modes of therapy are usually combined to meet the biologic, restorative, and esthetic requirements imposed by short clinical crowns. The complications presented by teeth with short clinical crowns demand a comprehensive treatment plan and proper sequencing of therapy to ensure a satisfactory result. Visualization of the desired result is a prerequisite of successful therapy. Short clinical crowns present many problems to the restorative dentist. Restorations should have proper form, function, and esthetics while promoting the maintenance of tissue health in the surrounding areas. However, adequate tooth structure for achieving these goals may not always be available. While it is difficult to precisely define minimum crown length, this study offers guidelines for defining a short clinical crown and suggests procedures for achieving a predictable result without compromising the periodontium. The consequences of placing a restoration on a tooth with insufficient crown length are discussed and various treatment methods are reviewed.

Alveolar Process↗

Clinical evaluation of a bioabsorbable regenerative material in mandibular class II furcation therapy.

30 periodontally compromised adult subjects with mandibular buccal class II furcation defects were recruited for this study. All selected defects were treated according to the biological principles of guided tissue regeneration. The subjects were randomly assigned to 2 parallel groups. The test group (n=15) received a bioabsorbable polyglycolic-polylactic membrane (PGA/PLA group); the control group (n=15) received a non-resorbable expanded polytetrafluoroethylene membrane (ePTFE group). After initial therapy, baseline measurements were recorded including plaque index, gingival index, vertical and horizontal probing depths, clinical attachment level and depth of the recession. Recall visits were made at 1, 2, 4, 6, 8, 12, and 24 weeks. At 12 months, all baseline clinical parameters were again measured. The data analysis did not demonstrate a significant difference between the 2 groups. The vertical probing depth and attachment level changes were statistically significant in each group. The postoperative recession was 0.6 mm in the ePTFE group (p<0.05) and 0.8 mm (p<0.05) in the PGA/PLA group. Compared to the initial measurements, the mean changes in horizontal probing depth were 2.7 mm and 2.5 mm (p<0.001), corresponding to mean reductions of 41.5% and 40.9% for the ePTFE and the PGA/PLA groups respectively. The results of this study suggest that 12 months after initial surgery, similar clinical improvements can be obtained in GTR therapy of buccal class II furcation lesions, regardless of whether bioabsorbable PGA/PLA membranes or non-resorbable ePTFE membranes are used.

Adult↗

The guided tissue regeneration principle in endodontic surgery: one-year postoperative results of large periapical lesions.

Twenty patients with large endodontic lesions, which failed to respond to conventional endodontic therapy, were selected for this study. The lesions had a radiographic diameter of at least 10 mm, were removed by periradicular surgery, before retrofilling the apices with either super EBA or dessicated zinc oxide-eugenol. In 10 test sites large e-PTFE membranes (Gortex) were placed to cover the lesions, while at the control sites the lesions were not covered before resuturing. Radio-graphic analysis of the lesions at 3, 6, 9 and 12 months revealed that lesions covered with the membranes healed quicker than the control lesions, and that the quality and quantity of the regenerated bone was superior when membranes were used. Results of the study indicate that guided tissue regeneration (GTR) principles can be effectively applied to the healing of large periapical lesions, especially in through-and-through lesions.

Adult↗

[Periodontal diseases. Clinical forms, epidemiology, etiology, prevention].

Periodontal diseases affect the teeth-supporting tissues and are the main causes of tooth loss in subjects older than 40 years. They are characterized by gingival bleeding, bone destruction and dental mobility and are due to bacterial proliferation on dental plaque and tartar. Several forms have been described according to the severity of alveolar bone destruction and to the patient's age. These diseases can be prevented by a strict bucco-dental hygiene applied jointly by the patient and the practitioner.

Adolescent↗

Guided tissue regeneration around dental implants in immediate extraction sockets: comparison of e-PTFE and a new titanium membrane.

To evaluate the efficacy of guided tissue regeneration around exposed implant threads, 16 implants were placed into fresh extraction sockets in beagle dogs. Polytetrafluoroethylene (e-PTFE) membranes and titanium membranes were used to cover the defects around implants. A control group did not receive any membranes. Results were evaluated histologically. The average gain in bone height was 2.1 mm for e-PTFE sites, 0.8 mm for titanium membranes, and 2.9 mm for control sites. The greatest gain in bone levels was seen for two sites that received e-PTFE membranes and remained covered for the entire evaluation interval. Within the limits of this study, clinical and histologic evidence demonstrated that, when primary coverage is maintained, the use of e-PTFE membranes can significantly enhance bone regeneration around implants.

Alveolar Bone Loss↗

[Bone regeneration in implantology. The use of Gore-Tex membranes: GTAM].

The use of expanded polytetrafluorethylene membranes to attain bone regeneration around dental implants is described. Membranes discourage "non-desirable" cells form colonizing the healing site. These cells are essentially derived from gingival epithelium and gingival connective tissue. It is suggested that this procedure could be employed directly after tooth extraction.

Bone Regeneration↗

[An x-ray computed tomography study with radiographic splints in implant evaluation].

CT-Scan provide a powerful diagnostic tool in the presurgical evaluation for endosseous implants. This article overviews a computer assisted system combined with a "marked radiographic stent" and a "surgical stent". The technique evaluates the ideal number, location and direction of the implants for a successful treatment.

Dental Implantation, Endosseous↗