[Show abstract][Hide abstract] ABSTRACT: This clinical case report describes and demonstrates successful use of recombinant human platelet-derived growth factor (rhPDGF-BB) in conjunction with autogenous bone, anorganic bone mineral, and barrier membranes to reconstruct severe alveolar bone defects. A combined sinus augmentation and vertical alveolar ridge augmentation was successfully performed. In addition, a significant amount of periodontal bone gain was achieved in close apposition to a previously denuded root surface, which is significant from a periodontal standpoint, given the possibility of vertical periodontal regeneration.
[Show abstract][Hide abstract] ABSTRACT: Tooth extraction is a traumatic procedure initiating a complex cascade of biochemical and histologic events that inevitably lead to a reduction of alveolar bone and soft tissue. These tissue alterations often lead to an esthetic compromise of the future implant restoration. The hard- and soft-tissue architecture surrounding the extraction defect largely dictates the course of dental implant treatment. The EDS or extraction-defect sounding classification is a novel system introduced to simplify the decision-making process when planning for dental implant therapy following tooth extraction. Dental implant treatment guidelines based on the EDS classification are discussed. A review of pretreatment evaluations necessary to prepare for esthetic implant procedures is also presented.
Journal of the California Dental Association 12/2005; 33(11):853-63. DOI:10.5005/jp-journals-10004-1001
[Show abstract][Hide abstract] ABSTRACT: Recently, platelet-rich plasma (PRP) has been proven to be an effective regeneration adjunct when combined with autogenous bone in the reconstruction of mandibular defects. However, little is known about the effect of PRP when combined with a bone allograft in the maxillary sinus. The purpose of this study was to quantitatively evaluate the ability of PRP to enhance bone regeneration in the maxillary sinus of sheep when combined with demineralized freeze-dried bone allograft (DFDBA) and cortical cancellous freeze-dried bone allograft (CCFDBA). Ten sheep were selected for bilateral sinus augmentation DFDBA + CCFDBA + PRP (test) and DFDBA + CCFDBA (control). Five were sacrificed at 3 months and the other 5 at 6 months. Hematology tests were performed for platelet count, and histology slides were obtained for histomorphometric analysis taking 2 measures of interest: total area (square millimeters) and percentage of bone fill. Student t tests showed no significant difference between test and control groups for total area (P > .25) and percentage of bone fill (P > .80) at either 3 or 6 months. The control group showed no statistical difference for total area (P < .095) and percentage of bone fill (P <.60) between 3- and 6-month healing times. The test group, however, showed a significant increase in total area (P <.025) but not in percentage of bone fill (P <.40) for the 2 healing periods. When the treatments were compared for interactions within the animal model, no clear tendency was evident for the test group to perform in relation to the control group regarding total area (r = .766, P < .01). A moderate tendency existed between the percentages of bone filled (r = .824, P < .005). Platelet-rich plasma showed higher platelet count than did the whole blood (2 to 5 times). However, no correlation was found between the log ratio and the bone measures. Within the limitations of this study, PRP failed to enhance or accelerate bone regeneration in the maxillary sinus of sheep when combined with bone allograft.
[Show abstract][Hide abstract] ABSTRACT: It is generally accepted that dental implants should not be placed in infected sites. However, the effect of periradicular infections of natural teeth on adjacent osseointegrated implants is less understood. The purpose of this study was to evaluate effects of periradicular lesions on osseointegration of existing implants. Study design Forty titanium solid root-form implants were placed close to premolars in dogs. After healing following implant placement, the adjacent premolars were treated in 1 of 4 ways: group A, no treatment of the adjacent premolar; group B, induction of a periradicular lesion followed by nonsurgical root canal therapy of the premolar; group C, induction of a periradicular lesion followed by nonsurgical root canal therapy of the premolar and surgical detoxification of the implant surface; and group D, induction of periradicular lesion and no treatment of the tooth. After 7(1/2) months, block sections were prepared and the percentage of osseointegration was analyzed histomorphometrically.
The average integration for implants in groups A-B was 54%, 74%, 56%, and 68%, respectively. One-way analysis of variance demonstrated no difference between the 4 groups ( P =.518).
The results of this study indicate that teeth with periradicular lesions do not adversely affect adjacent titanium solid root-form implants.
[Show abstract][Hide abstract] ABSTRACT: Contemporary standards of care, as well as ethical and legal issues, dictate the incorporation of dental implants into the general dental practice. Given the simplicity of current implant systems, most general dentists already possess the clinical expertise necessary to provide basic implant restorative services to their patients. However, due to the restricted manner in which dental implant training was propagated in the United States, and perhaps due to its foreign origins, many competent dentists seem unaware of this greatly beneficial innovation. There are a variety of educational resources available for the uninitiated dentist to gain proficiency in basic implant dentistry. The ideal education in implant dentistry provides supervised hands-on clinical training on live patients as well as didactic instruction by recognized teachers in implant dentistry. Such education may or may not be devoid of commercial bias. This paper will describe many of these opportunities.
Journal of the California Dental Association 12/2001; 29(11):757-64.
[Show abstract][Hide abstract] ABSTRACT: The uses of cytokine growth factors in soft tissue applications has been reported on. The scientific background and various processing techniques to prepare the autologous materials are reviewed here. An ongoing research project to study grafting of the maxillary sinus for bone regeneration and implant site preparation with the growth factor Platelet Rich Plasma is outlined.
[Show abstract][Hide abstract] ABSTRACT: This case report presents a clinical, radiographic, and histologic evaluation of 2 non-adjacent, hydroxyapatite-coated, root-form implants retrieved from the maxillary canine area of a patient after 7 years in function. Clinical examination revealed immobile implants with no sign of pathosis. Radiographic examination indicated close proximity of the bone to the implant surface without evidence of radiolucency. Histologically, the 2 implants appeared to be well integrated with the surrounding bone; 84% of the surface of the first implant and 79% of the surface of the second implant had close bone apposition at the interface. There was no evidence of dissolution of the hydroxyapatite coating. The bone appeared to be in immediate contact with the coating. These observations suggest that a particular hydroxyapatite coating on root-form implants can resist degradation during long-term function.
The International journal of oral & maxillofacial implants 03/2000; 15(3):438-43. · 1.49 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This split-mouth study was designed to evaluate regeneration of alveolar bone and periodontal attachment following implantation of allogeneic, freeze-dried, demineralized bone matrix (DBM). Buccal fenestration defects (6x4 mm) were created on the maxillary canine teeth in 6 beagle dogs. DBM was implanted into one randomly selected defect in each animal. The contralateral defect served as surgical control. Tissue blocks were harvested following a 4-week healing interval and prepared for histometric analysis. DBM was discernible in all implanted defects with limited evidence of bone metabolic activity. The DBM particles appeared invested within a dense connective tissue, often in close contact to the instrumented root. Fenestration defect height averaged 3.8+/-0.1 and 3.7+/-0.3 mm, total bone regeneration 0.9+/-0.9 and 0.4+/-1.2 mm, and total cementum regeneration 2.3+/-1.5 and 0.6+/-0.7 mm for DBM and control defects, respectively. Differences with regards to cementum regeneration were statistically significant (p=0.03). In summary, the results of this study suggest that DBM implants may enhance cementum regeneration in this defect model, and that they have no apparent effect on alveolar bone regeneration. Enhanced cementum regeneration may be possibly be explained by provisions for guided tissue regeneration from the implant suppressing a significant influence of the gingival connective tissue on the healing process. Moreover, a 4-week healing interval appears insufficient for turnover of DBM.
[Show abstract][Hide abstract] ABSTRACT: This randomized, split-mouth study was designed to evaluate the adjunctive effect of allogenic, freeze-dried, demineralized bone matrix (DBM) to guided tissue regeneration (GTR). Contralateral fenestration defects (6 x 4 mm) were created 6 mm apical to the buccal alveolar crest on maxillary canine teeth in 6 beagle dogs. DBM was implanted into one randomly selected fenestration defect. Expanded polytetrafluoroethylene (ePTFE) membranes were used to provide bilateral GTR. Tissue blocks including defects with overlying membranes and soft tissues were harvested following a four-week healing interval and prepared for histometric analysis. Differences between GTR+DBM and GTR defects were evaluated using a paired t-test (N = 6). DBM was discernible in all GTR+DBM defects with limited, if any, evidence of bone metabolic activity. Rather, the DBM particles appeared solidified within a dense connective tissue matrix, often in close contact to the instrumented root. There were no statistically significant differences between the GTR+DBM versus the GTR condition for any histometric parameter examined. Fenestration defect height averaged 3.7+/-0.3 and 3.9+/-0.3 mm, total bone regeneration 0.8+/-0.6 and 1.5+/-0.8 mm, and total cementum regeneration 2.0+/-1.3 and 1.6+/-1.7 mm for GTR+DBM and GTR defects, respectively. The histologic and histometric observations, in concert, suggest that allogenic freeze-dried DBM has no adjunctive effect to GTR in periodontal fenestration defects over a four-week healing interval. The critical findings were 1) the DBM particles remained, embedded in dense connective tissue without evidence of bone metabolic activity; and 2) limited and similar amounts of bone and cementum regeneration were observed for both the GTR+DBM and GTR defects.
Journal of Periodontology 09/1998; 69(8):851-6. DOI:10.1902/jop.19188.8.131.521 · 2.57 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The successful results of endosseous root form implants in the treatment of partially and completely edentulous patients has been made possible by the application of standardized surgical and prosthetic protocols. Different techniques have been published in the literature with the purpose of reducing implant prosthetic rehabilitation times. This clinical case report describes a new surgical concept and a technique to fabricate screw-retained provisional crowns for immediate loading of free-standing single tooth implants. Further clinical and histologic studies are necessary in order to promote routine clinical application of this technique.
[Show abstract][Hide abstract] ABSTRACT: The classical principles of osseointegration were based on a strict surgical protocol established through decades of experimental research and human clinical trials. These principles establish a sound scientific and clinical foundation for the neophyte implant surgeon. Research, however, is constantly accumulating, challenging a number of these original concepts and allowing deviation from the established protocol. It is anticipated that these changes will improve implant dentistry performance and expedite patient care. Sound clinical judgment based on experience and knowledge of the scientific literature must be exercised when deviations from the established protocol are considered.
Journal of the California Dental Association 12/1997; 25(12):843-51.
[Show abstract][Hide abstract] ABSTRACT: This randomized, split-mouth design study evaluated the adjunctive effect of allogeneic, freeze-dried, demineralized bone matrix on guided bone regeneration in a critical-size, supra-alveolar, peri-implant defect model. Contralateral supra-alveolar peri-implant defects, 5 mm in height, each including two titanium implants, were surgically created in five beagle dogs. Demineralized bone matrix in autologous blood was placed over the implants in one randomly selected mandibular jaw quadrant. A space-making expanded-polytetrafluoroethylene membrane was used to provide guided bone regeneration bilaterally. Following a 16-week healing interval, tissue blocks were harvested and prepared for histometric analysis. Differences between experimental conditions (guided bone regeneration sites with and without demineralized bone) were evaluated using paired t tests (n = 4). Demineralized bone particles were discernible, with limited signs of resorption. The bone matrix particles appeared to be solidified within a dense connective tissue matrix and in close contact with the implants. Limited matrix remineralization was apparent adjacent to the alveolar crest. No statistically significant differences were found between experimental conditions for any parameter examined. Peri-implant defect height averaged 5.0 +/- 0.2 mm and 4.9 +/- 0.4 mm, vertical bone regeneration 1.5 +/- 0.9 mm and 1.1 +/- 0.4 mm, osseointegration within the extent of the defect 10.0 +/- 3.9% and 15.3 +/- 5.3%, osseointegration within the extent of regenerated bone 30.4 +/- 13.7% and 52.1 +/- 17.9%, and osseointegration within the alveolar base 68.8 +/- 13.1% and 74.4 +/- 7.1% for guided bone sites with and without demineralized bone, respectively (P > .05). The results suggest that freeze-dried demineralized bone has no adjunctive effect on guided bone regeneration in supra-alveolar peri-implant defects, that guided bone regeneration has a limited potential to enhance alveolar regeneration in this defect model, and that a 16-week healing interval appears insufficient for turnover and maturation of demineralized bone under provisions for guided bone regeneration.
The International journal of oral & maxillofacial implants 01/1997; 12(5):634-42. · 1.49 Impact Factor