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Biomedical subjects

R G Triplett

Publications and source records attributed to R G Triplett.

At least 19 recordsLinked to original sources
PubMed2001

Effect of recombinant human bone morphogenetic protein-2 on bone regeneration and osseointegration of dental implants.

Recombinant human bone morphogenetic protein-2 (rhBMP-2) induced bone regeneration and osseointegration was evaluated in bony defects created within the hollow chamber of endosseous dental implants in 14 foxhound dogs. Bilateral extractions of mandibular premolars were performed and surgical implantation of 104 hollow cylinder implants followed after 8 weeks of healing. Experimental implants had their hollow chamber filled with 20 microg of rhBMP-2 delivered with a bovine collagen carrier, whereas the control implants had their apical chamber left empty. Dogs were followed for 2, 4, 8 and 12 weeks. Histomorphometric evaluation and immunohistochemical analysis were performed. Minimal bone was regenerated at 2 weeks for both groups. At 4 weeks, bone fill averaged 23.48% for the rhBMP-2 and 5.98% for the control group (P<0.05). At 8 weeks, mean bone fill was 20.94% and 7.75% for the rhBMP-2 and the controls, respectively (P<0.05). At 12 weeks, mean bone fill was 31.39% and 24.31% for the rhBMP-2 and control implants, respectively (P>0.05). Bone-implant contact (BIC) increased for both groups over time and at 8 weeks the rhBMP-2 BIC value was 18.65% and for the control 7.22% (P<0.05). At 12 weeks, the BIC was 43.78% and 21.05% for the rhBMP-2 and the control group, respectively (P<0.05). Immunohistochemical staining for type II collagen was positive only for parts of the collagen carrier and formation of cartilaginous intermediate was not observed in any of the specimens. The results suggest that, in confined defects adjacent to dental implants, rhBMP-2 can induce bone regeneration in close apposition to the implant surface.

Animals↗
PubMed1996

Autologous bone grafts and endosseous implants: complementary techniques.

PURPOSE: This article describes predictable techniques to augment contour- or height-deficient edentulous alveolar processes with autologous bone grafts for simultaneous or secondary placement of endosseous implants. METHODS: Augmentation bone grafts harvested from the ilium and mandible were used to reverse alveolar atrophy of the maxilla and mandible. Endosseous implants were either placed simultaneously with the graft or 6 to 9 months after grafting. Implant success was calculated only after an implant-supported prosthesis was in function for a minimum of 12 months. RESULTS: One hundred twenty-nine autologous bone grafts were placed in 99 patients. This included 70 grafts in the maxillary sinus, 32 onlay grafts, 14 veneer grafts, 9 saddle grafts, and 4 inlay grafts. Of these, 117 (90.7%) were successful. A total of 364 implants were placed in the grafted areas, 134 at the time of grafting and 230 6 to 9 months after grafting to allow time for osseous healing and remodeling. Three hundred twenty (87.9%) of the 364 implants placed in grafted areas were successful; 112 (83.6%) of the implants placed at the time of bone grafting and 208 (90.4%) of the implants placed secondarily in consolidated grafts. A total of 51 implants were placed in non-grafted areas in the same group of patients. Of these, 49 (96%) were successful. CONCLUSION: Autologous bone grafts can be used successfully to improve the ability to place endosseous implants. The successful placement of implants in autologous grafts is more predictable when the implants are placed secondarily, 6 to 9 months after bone grafting. Failure of individual implants does not imply failure of the bone graft. In most instances when implants failed to osseointegrate, enough bone graft remains to allow subsequent successful implant placement 6 to 9 months later.

Adolescent↗
PubMed1994

The use of guided tissue regeneration to improve implant osseointegration.

This prospective clinical study was designed to examine the use of guided tissue regeneration for the bony augmentation of alveolar bone around, or in preparation for, titanium endosseous implants. Sixty-three expanded polytetrafluorethylene membranes were used in 40 patients for various indications relating to implant placement. All of the membranes were subsequently removed. Postoperative infections were noted in nine membranes (14%), and dehiscence with exposure of the membrane to the oral cavity occurred in nine membranes (14%). Forty-five of the augmentations (71%) healed uneventfully and the membranes were removed at an average of 4.5 months. Sixty-one of the augmentations (96.8%) were found to be successful as determined by the clinical success of the implants and the presence of bone where there had been an osseous defect. Two cases (3.2%) were unsuccessful. Both of these were complicated by infection. The results indicate that guided tissue regeneration is a predictable method of augmenting the bone around titanium endosseous implants. Although the early complication rate was relatively high, the long-term success of the augmentation usually is not affected.

Alveolar Ridge Augmentation↗
PubMed1994

Anxiolytic therapy. Oral and intravenous sedation.

Anxiety associated with dental treatment is a well recognized problem that has a negative impact on patients' willingness to seek care. Today, this anxiety can be controlled by the practitioner. This article describes those techniques for both oral and parenteral administration as well as the pharmacokinetics of the drugs most commonly used for anxiety control.

Administration, Oral↗
PubMed1993

Guided tissue regeneration and endosseous dental implants.

This paper presents an evaluation of the use of the principles of guided tissue regeneration to correct the osseous defects associated with the placement of dental implants. The biologic rationale for the use of supplemental materials, such as decalcified freeze-dried bone allograft, is discussed. The results of this investigation suggest that the use of a physical barrier in combination with a bone allograft can produce successful results in 97% of the defects treated.

Alveolar Bone Loss↗
PubMed1992

The relationship of cigarette smoking to impaired intraoral wound healing: a review of evidence and implications for patient care.

Cigarette smoking has long been suspected to adversely effect wound healing. Review of our experiences with impaired wound healing in patients undergoing intraoral bone grafting and simultaneous implant placement implicated smoking as a potentially significant risk factor. Fifteen consecutive adult patients (5 smokers and 10 nonsmokers) who underwent intraoral bone grafting with simultaneous implant placement were retrospectively reviewed. Five of 15 patients experienced impaired wound healing defined as loss of bone and/or implants. Four of these five (80%) admitted to smoking in the perioperative period. One of 10 nonsmokers experienced problematic healing (10%). Although other factors may have played a role, cigarette smoking is a potentially controllable risk factor strongly associated with problem wounds in this series of patients. Evidence implicating smoking as a risk factor is presented and discussed.

Adult↗
PubMed1992

A retrospective evaluation of endosseous titanium implants in the partially edentulous patient.

Partial edentulism in 34 patients was consecutively treated using the Brånemark osseointegration technique. A total of 102 implants was tested for mobility, signs and symptoms of infection, and radiographic bone levels. All patients had at least a 6-month follow-up of prosthesis function (mean 22.5 months). An overall success rate of 88.2% was observed. Twenty-five of 28 maxillary implants and 65 of 74 mandibular implants were successfully placed and restored. Twelve failures were observed; 7 were not integrated at the time of stage 2 surgery while 5 occurred after prosthetic reconstruction. The results of this study suggest that the Brånemark osseointegration procedure can be used to treat partially edentulous patients with a high degree of success.

Adult↗
PubMed1991

Characterization of the extracellular matrix of the primate temporomandibular joint.

The distribution of type I and II collagens, fibronectin and the fibronectin-integrin receptor, tenascin, laminin, link protein, and cartilage-specific glycosaminoglycans was examined in the primate temporomandibular joint complex using an immunohistochemical approach. In general, type I collagen, fibronectin, and the fibronectin-integrin receptor were found to co-distribute throughout the joint complex. Immunostaining for these proteins was notably intense in the prechondroblastic and mineralization zones of the articular cartilages of the joint. Tenascin was identified in several structures of the joint, including the articular cartilages, where intense staining was observed in the prechondroblastic and cartilagenous zones. Laminin was detected only in the adventitia of blood vessels located in the attachment tissues of the disc and joint synovium. Cartilage-specific glycosaminoglycans and type II collagen were observed in the cartilagenous zones of the articular cartilages of the mandibular condyle and temporal bone. In addition, immunostaining for cartilage-specific glycosaminoglycans also was detected throughout the extracellular matrix surrounding "chondrocyte-like" cells located in the joint disc. Despite the localization of cartilage-specific glycosaminoglycans in the disc, type II collagen was not detected in this structure. It is suggested that a fibronectin-integrin receptor mechanism may be involved in the regulation of growth of the articular cartilages of the temporomandibular joint.

Animals↗
PubMed1991

Endosseous cylinder implants in severely atrophic mandibles.

A retrospective study was completed to assess the success rate of endosseous cylinder implants placed in mandibles that were 10 mm or less in maximum anterior height as measured from lateral cephalometric radiographs. Only implants that were located anteriorly between the mental foramina and loaded prosthetically for a minimum of 1 year were studied. Twenty-eight patients with a total of 130 Nobelpharma implants (forty-six 7 mm and eighty-four 10 mm) were included. The fixtures were evaluated following standard clinical criteria for success established for implants of this type. A total of 8 (two 7 mm and six 10 mm) of 130 implants failed, yielding an overall success rate of 94%. Major complications encountered included a complete mandibular fracture, a partial mandibular fracture, and a temporary bilateral mental nerve hypoesthesia.

Adult↗
PubMed1991

Cross-sectional radiography for implant site assessment.

An accurate tomographic technique is described for acquisition of optimal cross-sectional images of implant sites before implant surgery. The described technique is applicable to tomographic systems equipped with a cephalometric head positioner. This cross-sectional tomographic technique was performed on a series of patients and the images of the first 20 patients subsequently evaluated. The cross-sectional images allowed for the characterization of the alveolar crest and visualization of anatomic structures in a buccolingual dimension while providing an accurate estimation of available vertical space from the crest.

Alveolar Process↗
PubMed1990

Hemophilic pseudotumor of the mandible. Report of a case.

Hemophilic pseudotumor of bone is a rarely encountered lesion associated with hemophilia. To date, only eight cases in the mandible have been reported in the literature. A rare case occurring in the mandible of a 2 1/2-year-old child required the fabrication of a customized wound obturator for postoperative wound care after surgical curettage. The literature is reviewed and the obturator described.

Child, Preschool↗
PubMed1990

Cross-sectional radiography for implant site assessment.

An accurate tomographic technique is described for acquisition of optimal cross-sectional images of implant sites before implant surgery. The described technique is applicable to tomographic systems equipped with a cephalometric head positioner. This cross-sectional tomographic technique was performed on a series of patients and the images of the first 20 patients subsequently evaluated. The cross-sectional images allowed for the characterization of the alveolar crest and visualization of anatomic structures in a buccolingual dimension while providing an accurate estimation of available vertical space from the crest.

Cephalometry↗
PubMed1990

Mandibular fractures through endosseous cylinder implants: report of cases and review.

These case reports and review focus on three mandibular fractures that occurred through endosseous cylinder implant sites. The first patient, and most likely the second, had osteoporotic changes that affected their already atrophic mandibles. The third patient probably had an area of deficient mineralization or poorly consolidated bone in the region where the fracture developed. These bony conditions increased the potential for fracture. Although the exact mechanism by which such fractures occur is not known, an examination of past research suggests that stress concentration at the mandibular defect prepared for implant placement is a probable explanation. The site of an implant that has not yet osseointegrated acts as a site of tensile stress concentration and ultimately an area of weakness. Consequently, this area of weakness in a mandible with decreased bone density or mineralization is more prone to applied functional forces. Repeated submaximal functional forces in an area of bony weakness, such as an endosseous implant site, may lead to a spontaneous fracture with no associated trauma. With these factors in mind, several extra precautions should be taken when implants are placed in thin or weak mandibles.

Aged↗