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Biomedical subjects

U M Wikesjö

Publications and source records attributed to U M Wikesjö.

At least 19 recordsLinked to original sources
PubMed2001

Gingival recession defects and guided tissue regeneration: a review.

The last decade has seen an increasing number of clinical reports on guided tissue regeneration (GTR) for reconstruction of gingival recession defects. This article reviews the value of GTR in the management of gingival recession defects based on records from such reports. Studies and case-series using nonresorbable and bioresorbable membranes, studies comparing GTR to the subepithelial connective tissue graft (CTG) procedure, and histologic reports of healing following GTR, published in the English language from 1985 to 2000, were identified using a Medline search and were included in the data-base for this review. The Following pre- and post-treatment data were collated and evaluated for each of the reports: gingival recession depth, probing depth, clinical attachment level, and width of the keratinized gingiva. In perspective of the limitations of the studies reviewed, it has been shown that GTR may be used for reconstruction of gingival recession detects. Importantly it has not been shown that GTR provides an added clinical benefit for the patient treatment planned for reconstruction of gingival recession defects. i.e. GTR does not appear to offer a significant advantage over mucogingival procedures such as the connective tissue graft or the advanced flap procedure. It is imperative to recognize inherent technical difficulties associated with GTR including primary would closure and secondary membrane exposure: membrane exposures being negatively correlated to desired clinical outcomes. Also, membrane exposures appear consistently more common in smokers than in non-smokers. It is also imperative to recognize shortcomings and adverse effects including space maintenance and unacceptable foreign body reactions associated with some bioresorbable GTR technologies.

Absorbable Implants↗
PubMed2001

Hyaluronan supports recombinant human bone morphogenetic protein-2 induced bone reconstruction of advanced alveolar ridge defects in dogs. A pilot study.

BACKGROUND: Prosthetic-driven implant dentistry requires predictable procedures for alveolar ridge augmentation. The objective of this pilot study was to evaluate bone regeneration in mandibular, full-thickness, alveolar ridge, saddle-type defects following surgical implantation of recombinant human bone morphogenetic protein-2 (rhBMP-2) in a novel hyaluronan (HY) sponge carrier. This sponge was fabricated from auto-crosslinked HY. METHODS: Alveolar ridge defects (approximately 15 x 10 x 10 mm), 2 per jaw quadrant, were surgically prepared in each of 3 young adult American fox hounds. Four defects were immediately implanted with rhBMP-2/HY. Three defects were implanted with rhBMP-2 in an absorbable collagen sponge (ACS) carrier (positive control). The rhBMP-2 solution (1.5 ml at 0.2 mg/ml) was soak-loaded onto the HY and ACS sponges. Three defects were implanted with HY sponges soak-loaded with buffer without rhBMP-2 (negative control), while 2 defects served as surgical controls. The animals were euthanized at 12 weeks postsurgery for histometric analysis. RESULTS: Clinically, alveolar ridge defects receiving rhBMP-2/ACS exhibited a slight supracrestal expansion, while defects receiving rhBMP-2/HY were filled to contour. In contrast, the HY and surgical controls exhibited ridge collapse. rhBMP-2/HY-treated defects exhibited a dense bone quality without radiolucent regions observed in defects treated with rhBMP-2/ACS. The histometric analysis showed 100% bone fill for the rhBMP-2/ACS defects and 94%, 58%, and 65% bone fill for the rhBMP-2/HY, HY, and surgical control defects, respectively. CONCLUSIONS: The conclusions are based on data from 2 of 3 animals in the study. In one animal, no response to rhBMP-2 was observed with either carrier, and the animal may have been a non-responder of unknown nature. With this limitation, the observations herein suggest that: 1) HY supports significant bone induction by rhBMP-2; 2) the rhBMP-2-induced bone assumes qualities of the immediate resident bone; 3) HY alone exhibits no apparent osteoconductive potential; and 4) HY appears to resorb within a 12-week healing interval in the absence or presence of rhBMP-2. Thus, HY appears to be a suitable candidate carrier for rhBMP-2.

Absorbable Implants↗
PubMed2001

Augmentation of alveolar bone and dental implant osseointegration: clinical implications of studies with rhBMP-2.

BACKGROUND: The surgical placement of dental implants is governed primarily by the prosthetic design and secondarily by the morphology and quality of the alveolar bone. Implant placement may be difficult, if at all possible, due to alveolar ridge aberrations. In consequence, prosthetically dictated dental implant positioning often entails augmentation of the alveolar ridge and adjacent structures. The objective of this review is to discuss recent observations of the biologic potential, the clinical relevance, and the perspectives of the application of recombinant human bone morphogenetic protein-2 (rhBMP-2) technology for alveolar bone augmentation and dental implant fixation. METHODS: Our studies use discriminating, critical-size, supraalveolar defects in dogs to evaluate the biologic potential of the rhBMP-2 technology. We also use clinical modeling, including peri-implantitis and alveolar ridge defects and the maxillary sinus in preparation for clinical indications, in dogs and inhuman primates. RESULTS: The results suggest that rhBMP-2 has substantial potential to augment alveolar bone and support dental implant fixation and functional loading. CONCLUSION AND CLINICAL RELEVANCE: Inclusion of rhBMP-2 for alveolar bone augmentation and dental implant fixation will not only enhance the predictability of the existing clinical protocol but will also allow new approaches to these procedures.

Alveolar Bone Loss↗
PubMed2000

Periodontal repair in dogs: effect of transforming growth factor-beta 1 on alveolar bone and cementum regeneration.

BACKGROUND: Transforming growth factor-beta (TGF-beta) represents a family of growth-modulating proteins with fundamental roles in connective tissue and bone development. The objective of this study was to evaluate the potential for regeneration of alveolar bone and cementum following surgical implantation of recombinant human TGF-beta 1 (rhTGF-beta 1). METHOD: Bilateral, critical size, supra-alveolar periodontal defects in 5 beagle dogs were surgically implanted with rhTGF-beta 1 in a calcium carbonate carrier (CaCO3) or with carrier alone. The animals were euthanized at 4 weeks postsurgery and block-biopsies of the defects were processed for histologic and histometric analysis. RESULTS: Surgical implantation of rhTGF-beta 1 resulted in minimal, if any, stimulation of alveolar bone or cementum regeneration. Linear bone and cementum regeneration in rhTGF-beta 1-treated defects was 1.2+/-0.6 and 0.01+0.01 mm, respectively. Corresponding values for the controls were 1.0+/-0.6 and 0.01+/-0.03 mm. CONCLUSIONS: The results suggest that, under the conditions (dose, carrier, defect type) evaluated here, treatment of periodontal defects in beagle dogs with rhTGF-beta 1 may be of limited clinical benefit.

Alveolar Process↗
PubMed2000

Effect of smoking on periodontal health in molar teeth.

BACKGROUND: It is generally accepted that the primary cause of periodontitis is bacterial infection of long duration. In addition, there are several risk factors that may increase the probability and severity of periodontitis. For example, an increased breakdown of alveolar bone has been observed in smokers compared to never-smokers. The objective of this study was to investigate the association between cigarette smoking and periodontal health, in particular, furcation involvement in molar teeth. METHODS: One hundred twenty (120) adult regular dental patients, presenting with at least 20 teeth each, third molars excluded, were evaluated. Sixty of the subjects consumed an average (+/- SD) of 16.8 +/- 3.8 cigarettes daily and had smoked for 21.4 +/- 5.7 years. The remaining subjects presented a negative history of smoking. Periodontal conditions for the molar teeth were recorded at the first and second mandibular molar buccal furcation area. RESULTS: Oral hygiene standards and dental care habits did not differ notably between smokers and never-smokers. Smokers exhibited significantly fewer molar teeth than never-smokers (2.2 +/- 1.1 versus 3.0 +/- 0.8; P<0.01). Also, smokers exhibited significantly advanced gingival recession, probing depth, clinical attachment loss, furcation involvement, and tooth mobility compared to never-smokers (P<0.01). CONCLUSIONS: The results of this study suggest that long-term cigarette smoking significantly worsens periodontal health including degree and incidence of furcation involvement in molar teeth.

Adult↗
PubMed2000

Ridge augmentation following implantation of recombinant human bone morphogenetic protein-2 in the dog.

BACKGROUND: Recombinant human bone morphogenetic protein-2 (rhBMP-2) in an absorbable collagen sponge (ACS) carrier induces bone for reconstruction of skeletal defects. The rhBMP-2/ACS implant is prepared by administering a rhBMP-2 solution to dry ACS. Once prepared, rhBMP-2/ACS forms a moldable, cohesive, and adhesive implant. However, rhBMP-2/ACS does not have sufficient structural strength to withstand soft tissue compression at specific anatomic sites. To more fully understand the mechanisms that affect bone induction by rhBMP-2/ACS in the presence of soft tissue compression, it would be useful to have a preclinical model that appropriately simulates such circumstances in patients. This pilot study evaluated one such potential model. METHODS: Bilateral, Class III alveolar defects were surgically produced in 4 adult mongrel dogs following extraction of the mandibular fourth premolars and reduction of the alveolar ridge. After an 8-week healing interval, mucoperiosteal flaps were elevated and rhBMP-2/ACS or rhBMP-2/ACS combined with hydroxyapatite (HA) was implanted into contralateral defects. The animals were euthanized at 12 weeks post-augmentation and block biopsies processed for histologic evaluation. RESULTS: Limited augmentation followed implantation of rhBMP-2/ACS (0.7 +/- 0.6 mm). In contrast, sites receiving rhBMP-2/ACS/HA exhibited clinically relevant ridge augmentation (5.5 +/- 1.6 mm). Defects implanted with rhBMP-2/ACS exhibited dense trabeculation within the corpus of the reduced alveolar process. The cortices appeared intact without evidence of expansion into the defect area. Three defects receiving rhBMP-2/ACS/HA exhibited sparse bone trabeculae amidst HA particles, fibrovascular tissue, and marrow. Commonly, the HA particles were encapsulated by fibrous tissue. Some particles were observed in contact with bone. CONCLUSIONS: The results suggests that rhBMP-2/ACS has limited effect alone in this augmentation model of Class III alveolar ridge defects. Inclusion of HA into the rhBMP-2 construct results in clinically relevant augmentation, however, the quality of bone is compromised.

Absorbable Implants↗
PubMed2000

An in vitro screening model to evaluate root conditioning protocols for periodontal regenerative procedures.

BACKGROUND: Preclinical studies have shown that the condition of the root surface may play a decisive role for outcome of wound healing between a mucogingival flap and a denuded root surface. Root surface demineralization has been shown to promote the establishment of a new connective tissue attachment. Conversely, root conditioning with extracellular matrix proteins or fluorides has produced outcomes characterized by a long junctional epithelium. Collectively, present evidence suggests that early events in the healing sequel; i.e., the adsorption and adhesion of blood elements to the root surface are critical for outcomes of wound healing between a mucogingival flap and a denuded root surface. Ultimately understanding and control of these events are vital for successful design and execution of periodontal regenerative protocols, particularly those involving root conditioning. Consequently, the objective of this study was to develop a screening model for immediate evaluation of the influence of root conditioning protocols on the adsorption and adhesion of blood to dentin surfaces. METHODS: Planed and citric acid-treated human dentin surfaces were exposed to fresh blood allowed to clot and were then rinsed before scanning electron microscopy evaluation. RESULTS: Citric acid treated planed dentin surfaces presented a thick network of fibrin directly attaching to the dentin surface entrapping cellular elements, mainly erythrocytes. In contrast, untreated, planed dentin exhibited an amorphous appearance with sparse strands of adsorbed fibrous proteins and few adherent erythrocytes. CONCLUSIONS: This in vitro screening model may effectively distinguish dentin surfaces with potential for enhanced adsorption and adhesion of blood elements. Periodontal regenerative protocols involving root conditioning unsuccessful in maintaining the experimentally imposed fibrin clot in this model may have lesser clinical significance than those that do.

Alveolar Process↗
PubMed1999

Effects of cyclosporin A on the mandibular condylar cartilage in rats.

Twenty, 5-week-old, male, Sprague-Dawley rats were divided into a control and a cyclosporin A (CSA) group for evaluating effects of the drug on condylar cartilage. Animals in the treatment group daily received CSA (15 mg/kg body wt) in mineral oil by gastric feeding over a 4-week observation interval. Control animals received mineral oil only. Five animals from each group were killed at weeks 2 and 4 of study. After histological processing, five tissue sections from the mid-region of the condyle were selected and examined. Three compositional zones (articular fibrous, proliferative, and hypertrophic) of the superior, posteriosuperior and posterior regions of the condylar cartilage were evaluated by light microscopy. At week 2, total condylar cartilage thickness was similar in the CSA and control groups, but the thickness of each zone was altered in CSA-treated animals, including a decrease of the fibrous and proliferative zones and an increase in hypertrophic zone compared to control (P<0.05). At week 4, CSA-treated animals exhibited overall decreased cartilage thickness, including decreased thickness of each zone compared to control (P<0.05). The results suggest that CSA has an inhibitory effect on the maturation of the mandibular condyle in rats.

Animals↗
PubMed1999

Periodontal repair in dogs: histologic observations of guided tissue regeneration with a prostaglandin E1 analog/methacrylate composite.

This report describes observations of healing following guided tissue regeneration (GTR) including surgical implantation of the prostaglandin E1 analog misoprostol with calcium-layered methacrylate particles. Critical size, supra-alveolar periodontal defects were surgically created around the 3rd and 4th mandibular premolar teeth in 4 beagle dogs. Wound management included soaking with a 24 microg/ml misoprostol solution and implantation of the misoprostol/methacrylate composite. One jaw quadrant per animal was prepared for GTR using expanded polytetrafluoroethylene membranes. The gingival flaps were coronally advanced and sutured to submerge the teeth. The tissues covering the surgical sites daily received topical misoprostol in an oral adhesive over the 4-week healing interval. Upon euthanasia, tissue blocks were prepared for histometric analysis of regeneration of alveolar bone and cementum, root resorption and ankylosis. The defect area underneath the membrane and the density of methacrylate particles were recorded for the GTR defects. The methacrylate particles appeared encapsulated in a dense connective tissue without signs of an inflammatory reaction, some in contact to newly formed bone. Alveolar bone regeneration height averaged (+/-SD) 1.2+/-1.0 and 1.0+/-0.6 mm for GTR and non-GTR defects, respectively. Corresponding values for bone regeneration area were 1.3+/-1.0 and 0.7+/-0.5 mm2. Cementum regeneration was confined to the apical aspect of the defects. Small areas of root resorption and ankylosis were observed for all teeth. Bone regeneration area correlated positively to the defect area and negatively to the density of methacrylate particles in the GTR defects. The histologic observations suggest that the methacrylate composite has marginal potential to promote bone and cementum regeneration under provisions for GTR.

Alveolar Bone Loss↗
PubMed1999

Periodontal repair in dogs: effect of rhBMP-2 concentration on regeneration of alveolar bone and periodontal attachment.

The objective of this study was to evaluate the effect of recombinant human bone morphogenetic protein-2 (rhBMP-2) concentration on regeneration of alveolar bone and cementum, and on associated root resorption and ankylosis. Contralateral, critical size, supra-alveolar, periodontal defects were surgically produced and immediately implanted with rhBMP-2 in an absorbable collagen sponge (ACS) carrier in 8, young adult, male, beagle dogs. 6 animals received rhBMP-2/ACS (rhBMP-2 at 0.05, 0.10, or 0.20 mg/mL; total construct volume/defect approximately 4.0 mL) in contralateral defects following an incomplete block design. 2 animals received rhBMP-2/ACS (rhBMP-2 at 0 and 0.10 mg/mL) in contralateral defects (controls). The animals were euthanised at 8 weeks post-surgery and block sections of the defects were collected for histologic and histometric analysis. Supra-alveolar periodontal defects receiving rhBMP-2 at 0.05, 0.10, or 0.20 mg/ml exhibited extensive alveolar regeneration comprising 86%, 96%, and 88% of the defect height, respectively. Cementum regeneration encompassed 8%, 6%, and 8% of the defect height, respectively. Root resorption was observed for all rhBMP-2 concentrations. Ankylosis was observed in almost all teeth receiving rhBMP-2. Control defects without rhBMP-2 exhibited limited, if any, evidence of alveolar bone and cementum regeneration, root resorption, or ankylosis. Within the selected rhBMP-2 concentration and observation interval, there appear to be no meaningful differences in regeneration of alveolar bone and cementum. There also appear to be no significant differences in the incidence and extent of root resorption and ankylosis, though there may be a positive correlation with rhBMP-2 concentration.

Absorbable Implants↗
PubMed1999

Effect of human bone morphogenetic protein 2 implant on tooth eruption in an experimental design.

This study evaluated the influence of recombinant human bone morphogenetic protein 2 (rhBMP-2) on the development and eruption of the secondary dentition. Primary premolar tooth extraction sockets in 12 16-week-old felines were implanted with either rhBMP-2, in collagen sponge or with buffer/absorbable collagen sponge (ACS). Unoperated jaw quadrants served as controls. Experimental conditions were randomized between jaw quadrants in all animals. Two animals receiving rhBMP-2/ACS and buffer/ACS in two quadrants per implant were sacrificed at 4 weeks postsurgery. Ten animals receiving rhBMP-2/ACS (two quadrants), buffer/ACS implants (one quadrant), and one quadrant serving as an unoperated control were evaluated at 12 weeks postsurgery. Clinical assessments included healing, eruption patterns, and crown development. Radiographic assessments included tooth development, eruption patterns, and bone formation. Histological observations were also made from the 4-week animals. The secondary dentition remained unerupted at 4 weeks postsurgery. Histological analysis showed normal alveolar bone coronal to the erupting teeth in rhBMP-2/ACS-implanted quadrants. At 12 weeks postsurgery, all teeth were erupted without differences between quadrants. Clinically, the crowns of all teeth were normal. Radiographs suggested that teeth in rhBMP-2/ACS- and buffer/ACS-implanted jaw quadrants exhibited similar tooth development and eruption patterns as the normal control. The evidence from this study suggests that surgical implantation of rh-BMP-2/ACS in the pathway of the developing and erupting secondary dentition does not interfere with the normal development and eruption patterns of the teeth.

Absorbable Implants↗
PubMed1999

Effects of cyclosporin A on alveolar bone: an experimental study in the rat.

BACKGROUND: There have been several investigations on the role of cyclosporin A (CSA) in gingival hyperplasia in both animals and humans. However, less attention has been given to the drug's effect on alveolar bone. This study used light microscopy to histologically and histometrically evaluate the effects of CSA on alveolar bone in the rat. METHODS: Sixty, 6-week-old Sprague-Dawley rats were separated into test and control groups. Animals in the test group received CSA in mineral oil (30 mg/kg body weight) daily by gastric feeding over the 6-week study. Control animals received only mineral oil. Ten animals from each group were sacrificed at weeks 2, 4, and 6. After histologic processing, the labial crest of the alveolar bone in the anterior mandible was evaluated by light microscopy. RESULTS: A distinct pattern of increased osteoclasia and reduced bone formation was observed in the CSA-exposed animals compared to the controls. Increased osteoclasia was observed in periodontal sites and decreased bone formation was observed in symphyseal sites. CONCLUSIONS: The results suggest that CSA has distinct effects on alveolar bone.

Alveolar Bone Loss↗
PubMed1998

Alveolar bone formation at dental implant dehiscence defects following guided bone regeneration and xenogeneic freeze-dried demineralized bone matrix.

The present study evaluated rate and extent of alveolar bone formation in dental implant dehiscence defects following guided bone regeneration (GBR) and implantation of xenogeneic freeze-dried demineralized bone matrix (xDBM). A total of 16 titanium plasma-sprayed (TPS) and 16 hydroxyapatite-coated (HA) titanium cylinder implants were inserted in 4 mongrel dogs following extraction of the mandibular premolar teeth. Four implant sites per jaw quadrant (2 TPS and 2 HA implant sites) were prepared into extraction sockets in each dog. Buccal alveolar bone was removed to create 3 x 5 mm dehiscence defects. Two jaw quadrants in separate animals received GBR, GBR + xDBM, xDBM (control), or gingival flap surgery alone (GFS; control). Thus, four conditions were available for each implant type (TPS or HA): GBR, GBR + xDBM; xDBM and GFS. The animals received fluorescent bone labels to allow observations of rate and extent of bone formation. Animals were sacrificed at 12 weeks postsurgery and block sections were harvested for histologic analysis. There were no apparent histologic differences between TPS and HA implant defects. GBR and GBR + xDBM resulted in almost complete bone closure of the dental implant dehiscence defect. Rate of bone formation appeared higher following GBR alone. Extent of bone formation appeared somewhat greater following GBR + xDBM; however, delayed. xDBM alone did not adequately resolve the bony defect. In conclusion, GBR results in rapid, clinically relevant bone closure of dental implant dehiscence defects. Adjunctive implantation of xDBM does not appear to significantly improve the healing response in the model used.

Alveolar Process↗
PubMed1998

Clinical and antimicrobial effects of a single episode of subgingival irrigation with tetracycline HCl or chlorhexidine in deep periodontal pockets.

15 adults, each providing 4 non-adjacent untreated periodontal pockets with a probing depth (PD) exceeding 6 mm, volunteered for a randomized, split-mouth, double-blind, clinical study evaluating subgingival irrigation with chlorhexidine (CHX) or tetracycline HCl (TTC). The study protocol included oral hygiene instructions followed by scaling and root planing. Experimental and immediately adjacent teeth did not receive instrumentation. The 4 deep periodontal pockets in each patient were assigned to be irrigated with 150 ml CHX (0.12%), TTC (10 or 50 mg/ml; TTC10, TTC50), or sterile saline (control) in a single episode. Post-irrigation mechanical plaque control was supported by 2x daily CHX rinses throughout the 12-week observation interval. Recordings of oral hygiene (P1I), gingival health (GI), bleeding on probing (BoP), probing depth (PD), clinical attachment level (CAL), and microbial morphotypes from subgingival paper point samples were performed pre-irrigation, and at 1, 2, 4, 6, 8, 10, and 12 weeks post-irrigation. Mean post-irrigation P1I was low, fluctuating between 0.0 and 0.4, without significant differences between experimental groups. Mean pre-irrigation GI approximated 1.4 and reached 0.8 at the exit of study without significant differences between experimental groups. All experimental sites exhibited BoP pre-irrigation. BoP was significantly reduced in TTC50 compared to TTC10, CHX and control sites from week 8 post-irrigation. PDs were reduced for the experimental groups with TTC50 exhibiting the strongest reduction. CALs remained unaltered from pre-irrigation for TTC10, CHX and control sites over the 12-week observation interval, whereas TTC50 sites consistently improved to significantly differ from all other groups at week 10 and 12 post-irrigation. The distribution of bacterial morphotypes was significantly altered towards one of periodontal health for all experimental groups with a profound effect for TTC50 sites. Our results suggest that subgingival irrigation with TTC solutions at high concentrations may have a role in the management of adult periodontitis.

Adult↗
PubMed1998

Effect of allogeneic freeze-dried demineralized bone matrix on regeneration of alveolar bone and periodontal attachment in dogs.

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.

Alveolar Bone Loss↗
PubMed1998

Periodontal repair in dogs: effect of recombinant human transforming growth factor-beta1 on guided tissue regeneration.

This study evaluated alveolar bone and cementum regeneration following surgical implantation of recombinant human transforming growth factor-beta1 (rhTGF-beta1) in conjunction with guided tissue regeneration (GTR). Supraalveolar, critical size, periodontal defects were surgically created around the 3rd and 4th mandibular premolar teeth in right and left jaw quadrants in 5 beagle dogs. Alternate jaw quadrants in consecutive animals received rhTGF-beta1, in a CaCO3/hydroxyethyl starch carrier with GTR, or carrier with GTR alone (control). 20 microg of rhTGF-beta1 in buffer solution was incorporated into approximately 0.8 ml of carrier for each defect scheduled to receive rhTGF-beta1. Animals were sacrificed at week 4 postsurgery and tissue blocks were harvested and processed for histometric analysis. Clinical healing was generally uneventful. Minor membrane exposures were observed. Defects with membrane exposure displayed an inflammatory infiltrate underneath the membrane. Bone regeneration of trabecular nature, apparent in all animals, was generally limited to the very apical aspect of the defects. Cementum regeneration was limited without obvious differences between experimental conditions. Comparing rhTGF-beta1, to control defects, statistically significant differences were found for area (1.8+/-0.4 and 1.3+/-0.6 mm2, respectively; p<0.05) and density (0.3+/-0.1 and 0.2+/-0.03, respectively; p<0.05) of alveolar bone regeneration. Observed differences are small and represent a clinically insignificant potential for enhanced regeneration in this preclinical model. Within the limitations of study, it may be concluded that rhTGF-beta1 has a restricted potential to enhance alveolar bone regeneration in conjunction with GTR.

Alveolar Bone Loss↗