Treatment of intraosseous defects with bioabsorbable barriers alone or in combination with decalcified freeze-dried bone allograft: a randomized clinical trial

Predictability and Clinical Stability of Barrier Membranes in Treatment of Periodontal Intrabony Defects: A Systematic Review and Meta-Analysis

The adjunctive use of GTR membranes helps us to achieve predictable periodontal regeneration. The aim of this systematic review was to evaluate and compare the treatment efficacy of resorbable versus non-resorbable barrier membranes used in guided tissue regeneration in the treatment of intrabony defects in chronic periodontitis patients. The following databases were searched: Medline, the Cochrane Central Register of Controlled Trails (CENTRAL), SCOPUS, EMBASE. Randomized clinical trials (RCTs) published in English languages over the past 25 years were included. The primary outcomes assessed were: change of probing pocket depth (PD), change in clinical attachment level (CAL) and gingival recession coverage (GRC), and intrabony defect fill (IBDF). A total of eight RCTs were included for systematic review. The outcome of GR at a six-month interval revealed a significant difference in treatment effect with a mean difference of 0.42, 95% CI [0.02, 0.81]; Z = 2.09, (p = 0.04) favouring the resorbable membrane group. The intrabony defect depth fill at a 12-month interval revealed a significant difference in treatment effect with MD of 0.79, p = 0.00001; favoring the resorbable membrane group. The resorbable membrane showed a significant improvement in gingival recession coverage and intrabony defect fill, owing to its advantage of avoiding the second surgical intervention.

GTR Treatment in Furcation Grade II Periodontal Defects with the Recently Reintroduced Guidor PLA Matrix Barrier: A Case Series with Chronological Step-by-Step Illustrations

Molars with a furcation involvement (FI) exceeding grade 1 according to Hamp's classification are at approximately doubled risk of tooth loss. Guided tissue regeneration (GTR) is a regenerative approach in the treatment of periodontal defects and is aimed at achieving new clinical attachment formation. The aim of this case series was to assess the efficacy of a newly reintroduced polylactic acid (PLA) matrix barrier and to evaluate the feasibility of the surgical approach. 11 patients with an average age of 58.7 years were treated with GTR using a PLA matrix barrier. Patients were instructed not to brush and chew on the treated side for 4 weeks. A gentle clinical probing was performed after 6 months for the first time after surgery. The patients were included into individual maintenance program at three months' interval. The clinical improvement was expressed by reduced horizontal penetration of the probe accompanied by vast resolution of the vertical defect component. The change from grade II to grade I or complete resolution of the FI could be seen in 8 from 11 sites included. The newly reintroduced PLA matrix barrier showed promising results after a 12-month observation period with clinical attachment gain.

Biomimetic hydroxyapatite used in the treatment of periodontal intrabony pockets: clinical and radiological analysis

AIM

Hydroxyapatite (PA) has a chemical composition and physical structure very similar to natural bone and therefore it has been considered to be the ideal biomaterial able to ensure a biomimetic scaffold to use in bone tissue engineering. The aim of this study is to clinically test hydroxyapatite used as osteoconductive biomaterial in the treatment of periodontal bone defects. Clinical and radiological evaluations were conducted at 6, 12 and 18 months after the surgery.

MATERIALS AND METHODS

Forty patients with 2- and 3-wall intrabony pockets were enrolled in this study. PPD, CAL, radiographic depth (RD) and angular defects were preoperatively measured. After surgery, patients were re-evaluated every 6 months for 18 months. Statistical analyses were also performed to investigate any differences between preoperative and postoperative measurements.

RESULTS

Paired t-test samples conducted on the data obtained at baseline and 18 months after, showed significant (p<0.01) differences in each measurement performed. The role of preoperative RD was demonstrated to be a significant key factor (p<0.01). A relevant correlation between preoperative PPD and CAL gain was also found.

CONCLUSIONS

Within the limitations of this study, the absence of anatomical variables, except the morphology of the bone defect, emphasizes the importance of the proper surgical approach and the graft material used.

Combination of bone allograft, barrier membrane and doxycycline in the treatment of infrabony periodontal defects: A comparative trial

Aim

The purpose of the present study was to compare the regenerative potential of noncontained periodontal infrabony defects treated with decalcified freeze-dried bone allograft (DFDBA) and barrier membrane with or without local doxycycline.

Methods

This study included 48 one- or two-wall infrabony defects from 24 patients (age: 30–65 years) seeking treatment for chronic periodontitis. Defects were randomly divided into two groups and were treated with a combination of DFDBA and barrier membrane, either alone (combined treatment group) or with local doxycycline (combined treatment + doxycycline group). At baseline (before surgery) and 3 and 6 months after surgery, the pocket probing depth (PPD), clinical attachment level (CAL), radiological bone fill (RBF), and alveolar height reduction (AHR) were recorded. Analysis of variance and the Newman–Keuls post hoc test were used for statistical analysis. A two-tailed p-value of less than 0.05 was considered to be statistically significant.

Results

In the combined treatment group, the PPD reduction was 2.00 ± 0.38 mm (32%), CAL gain was 1.25 ± 0.31 mm (17.9%), and RBF was 0.75 ± 0.31 mm (20.7%) after 6 months. In the combined treatment + doxycycline group, these values were 2.75 ± 0.37 mm (44%), 1.5 ± 0.27 mm (21.1%), and 1.13 ± 0.23 mm (28.1%), respectively. AHR values for the groups without and with doxycycline were 12.5% and 9.4%, respectively.

Conclusion

There was no significant difference in the regeneration of noncontained periodontal infrabony defects between groups treated with DFDBA and barrier membrane with or without doxycycline.

Clinical and radiographic evaluation of periodontal intrabony defects by open flap surgery alone or in combination with Biocollagen(®) membrane: A randomized clinical trial

BACKGROUND

Guided tissue regeneration (GTR) is often incorporated in regenerative periodontal surgical procedures. However, the actual benefits of adding GTR to such a procedure remain undocumented. The purpose of this randomized controlled trial was to investigate the contribution of GTR to the outcomes of open flap debridement (OFD) in the treatment of intrabony defects.

MATERIALS AND METHODS

A total of 16 patients of both sexes satisfying the criteria of chronic periodontitis and each of whom displayed one intrabony defect were randomly assigned to two groups, i.e. either treated with open flap surgery and GTR (group 1) or with open flap surgery alone (group 2), in this parallel-arm study. The soft tissue and hard tissue measurements, including probing pocket depth (PD), clinical attachment level (CAL), and bone mineral density were recorded at baseline and 3,6 and 12 months after surgery. The differences with a P < 0.05 were considered significant.

RESULTS

Results showed that the membrane group showed significant difference when compared with open flap surgery alone, in relation to the degree of periodontal pocket, clinical attachment loss, and bone density.

CONCLUSION

The findings of this study suggest that biocollagen membrane could be considered as an option in the treatment of intrabony defects. Biocollagen membrane alone gives favorable clinical results in the treatment of intrabony defects. Open flap debridement resulted in acceptable clinical results in the treatment of intrabony defects.

Bone substitutes for peri-implant defects of postextraction implants

Placement of implants in fresh sockets is an alternative to try to reduce physiological resorption of alveolar ridge after tooth extraction. This surgery can be used to preserve the bone architecture and also accelerate the restorative procedure. However, the diastasis observed between bone and implant may influence osseointegration. So, autogenous bone graft and/or biomaterials have been used to fill this gap. Considering the importance of bone repair for treatment with implants placed immediately after tooth extraction, this study aimed to present a literature review about biomaterials surrounding immediate dental implants. The search included 56 articles published from 1969 to 2012. The results were based on data analysis and discussion. It was observed that implant fixation immediately after extraction is a reliable alternative to reduce the treatment length of prosthetic restoration. In general, the biomaterial should be used to increase bone/implant contact and enhance osseointegration.

Evaluation of calcium sulphate barrier to collagen membrane in intrabony defects

PURPOSE

The aim of this study was to clinically and radiographically evaluate and compare treatment of intrabony defects with the use of decalcified freeze-dried bone allograft in combination with a calcium sulphate barrier to collagen membrane.

METHODS

Twelve patients having chronic periodontal disease aged 20 to 50 years and with a probing depth >6 mm were selected. Classification of patient defects into experimental and control groups was made randomly. In the test group, a calcium sulphate barrier membrane, and in control group, a collagen membrane, was used in conjunction with decalcified freeze-dried bone graft in both sides. Ancillary parameters as well as soft tissue parameters along with radiographs were taken at baseline and after 6 months of surgery. Parameters assessed were plaque index, modified gingival index, probing depth, relative attachment level, and location of the gingival margin. A Student's t-test was done for intragroup and a paired t-test for intergroup analysis.

RESULTS

Intragroup analysis revealed statistically significant improvement in all the ancillary parameters and soft tissue parameters with no statistically significant difference in intergroup analysis.

CONCLUSIONS

The study concluded that a calcium sulphate barrier was comparable to collagen membrane in achieving clinical benefits and hence it can be used as an economical alternative to collagen membrane.

Use of an Autogenous Cortical Graft in Combination with Guided Tissue Regeneration for Treatment of an Infrabony Defect

Infrabony periodontal defects are common findings encountered during complete oral examinations. Treatment options for infrabony lesions are aimed at meeting client demands as well as patient needs. Deciding on how to treat these lesions depends on the nature and degree of disease present as well as having the materials available to improve the chances of achieving the greatest clinical success. Bone grafting of an infrabony defect of the left mandibular first molar tooth of a dog using an autogenous cortical graft harvested with a reusable bone grafter in combination with guided tissue regeneration is described.

Advanced reconstructive technologies for periodontal tissue repair

Reconstructive therapies to promote the regeneration of lost periodontal support have been investigated through both preclinical and clinical studies. Advanced regenerative technologies using new barrier-membrane techniques, cell-growth-stimulating proteins or gene-delivery applications have entered the clinical arena. Wound-healing approaches using growth factors to target the restoration of tooth-supporting bone, periodontal ligament and cementum are shown to significantly advance the field of periodontal-regenerative medicine. Topical delivery of growth factors, such as platelet-derived growth factor, fibroblast growth factor or bone morphogenetic proteins, to periodontal wounds has demonstrated promising results. Future directions in the delivery of growth factors or other signaling models involve the development of innovative scaffolding matrices, cell therapy and gene transfer, and these issues are discussed in this paper.

Clinical evaluation of guided tissue regeneration combined with autogenous bone or autogenous bone mixed with bioactive glass in intrabony defects

Conflicting data exist on the combined use of grafting materials and barrier membranes in comparison to guided tissue regeneration (GTR) with membrane alone. The aim of the present study was to compare the clinical outcomes of GTR with collagen membrane (CM) alone (control group) or CM combined with autogenous bone graft (test group 1) or autogenous bone mixed with bioactive glass (test group 2) in intrabony defects. A total of 32 intraosseous defects in 22 subjects were treated randomly. After 6 months, significant probing depth reduction, clinical attachment level gain (CAL) and defect resolution were observed in all groups with significantly greater improvements in the test groups. There was no significant difference between the two test groups in any parameter. Results of the present study suggest that autogenous bone can be mixed with bioactive glass if the amount of the harvested bone is not sufficient.

Bone regeneration potential of a soybean-based filler: experimental study in a rabbit cancellous bone defects

Autologous and allogenic bone grafts are considered as materials of choice for bone reconstructive surgery, but limited availability, risks of transmittable diseases and inconsistent clinical performances have prompted the development of alternative biomaterials. The present work compares the bone regeneration potential of a soybean based bone filler (SB bone filler) in comparison to a commercial 50:50 poly(D: ,L: lactide-glycolide)-based bone graft (Fisiograft((R)) gel) when implanted into a critical size defect (6-mm diameter, 10-mm length) in rabbit distal femurs. The histomorphometric and microhardness analyses of femoral condyles 4, 8, 16 and 24 weeks after surgery showed that no significant difference was found in the percentage of both bone repair and bone in-growth in the external, medium and inner defect areas. The SB filler-treated defects showed significantly higher outer bone formation and microhardness results at 24 weeks than Fisiograft((R)) gel (P < 0.05). Soybean-based biomaterials clearly promoted bone repair through a mechanism of action that is likely to involve both the scaffolding role of the biomaterial for osteoblasts and the induction of their differentiation.

[The use of beta-tricalcium phosphate and bovine bone matrix in the guided tissue regeneration treatment of deep infra-bony defects]

INTRODUCTION

The primary goal of bone regeneration procedures with application of various regenerative biologic agents and biomaterials is to facilitate the formation of periodontal tissues lost as a result of periodontitis.

OBJECTIVE

The aim of the study was to compare clinical outcome of the guided tissue regeneration (GTR) treatment with the use of beta-tricalcium phosphate and with bovine bone matrix in human deep intra-osseous defects.

METHODS

Twenty-one systemically healthy subjects with moderate to advanced periodontitis, between 30 and 56 years of age, 11 females and 10 males, were selected. Patients having two similar inter-proximal defects with pocket probing depths following initial therapy greater than 5 mm were recruited for the study. Experimental sites were grafted with pure beta-tricalcium phosphate biomaterial (Cerasorb) and a biomembrane, while control sites were treated with bovine-bone hydroxiapatite xenograft (Bio-oss) and a biomembrane. Immediately before surgery and 12 months after surgery, pocket probing depth (PPD), epithelial attachment level (EAL) and gingival recession (GR) were evaluated.

RESULTS

In the experimental group PPD amounted to 6.76 +/- 0.83 mm before surgery, and decreased significantly to 2.67 +/- 0.48 mm 12 months following surgery, while in the control group PPD significantly decreased from 7.14 +/- 0.65 mm presurgically to 2.85 +/- 0.57 mm postsurgically. After one year, EAL gain was 2.76 +/- 0.99 mm in the experimental group, and 3.24 +/- 0.16 mm in the control group. After twelve months postoperatively GR amounted to 1.33 +/- 0.79 mm in the experimental group and to 1.05 +/- 0.80 mm in the control group. No statistically significant differences for PPD reduction, EAL gain and GR increase were detected between the groups.

CONCLUSION

Results from the present study indicate that GTR treatment of deep intra-osseous defects with Bio-oss and Cerasorb resulted in clinically and statistically significant improvement of EAL gain and PPD reduction. A GR was slightly increased, with no statistical significance.

Regeneration of periodontal tissues: guided tissue regeneration

The concept that only fibroblasts from the periodontal ligament or undifferentiated mesenchymal cells have the potential to re-create the original periodontal attachment has been long recognized. Based on this concept, guided tissue regeneration has been applied with variable success to regenerate periodontal defects. Quantitative analysis of clinical outcomes after guided tissue regeneration suggests that this therapy is a successful and predictable procedure to treat narrow intrabony defects and class II mandibular furcations, but offers limited benefits in the treatment of other types of periodontal defects.

The management of mucosal fenestration: a report of two cases

AIM

To report on the management of two patients with mucosal fenestration of root apices.

SUMMARY

Two cases of mucosal fenestration of root apices were treated by a combination of nonsurgical root canal treatment and surgery. Root-end resection was performed to bring the root apices within the alveolus before root-end filling and packing of the bony defects with demineralized freeze-dried bone allograft. The areas were then covered with connective tissue grafts taken from the hard palate before repositioning the mucogingival flap. At 1 year follow-up, the mucosal fenestrations were completely healed by soft tissue graft coverage, and radiographs revealed bony healing.

KEY LEARNING POINTS

* Connective tissue grafts can be used to manage mucosal fenestration. * Periradicular surgery and connective tissue grafts can be used in combination.

In vitro osteogenic differentiation of human mesenchymal stem cells and in vivo bone formation in composite nanofiber meshes

Tissue engineering has become an alternative method to traditional surgical treatments for the repair of bone defects, and an appropriate scaffold supporting bone formation is a key element in this approach. In the present study, nanofibrous organic and inorganic composite scaffolds containing nano-sized demineralized bone powders (DBPs) with biodegradable poly(L-lactide) (PLA) were developed using an electrospinning process for engineering bone. To assess their biocompatibility, in vitro osteogenic differentiation of human mandible-derived mesenchymal stem cells (hMSCs) cultured on PLA or PLA/DBP composite nanofiber scaffolds were examined. The mineralization of hMSCs cultured with osteogenic supplements on the PLA/DBP nanofiber scaffolds was remarkably greater than on the PLA nanofiber scaffold during the first 14 days of culture but reached the same level after 21 days. The in vivo osteoconductive effect of PLA/DBP nanofibrous scaffolds was further investigated using rats with critical-sized skull defects. Micro-computerized tomography revealed that a greater amount of newly formed bone extended across the defect area in PLA/DBP scaffolds than in the nonimplant and PLA scaffolds 12 weeks after implantation and that the defect size was almost 90% smaller. Therefore, PLA/DBP composite nanofiber scaffolds may serve as a favorable matrix for the regeneration of bone tissue.

Demineralized freeze-dried bone allograft and platelet-rich plasma vs platelet-rich plasma alone in infrabony defects: a clinical and radiographic evaluation

The objective of this work is to compare the clinical and radiographic outcomes of demineralized freeze-dried bone allograft (DFDBA)/platelet-rich plasma (PRP) combination with PRP alone for the treatment of infrabony defects 18 months after surgery and to examine the influence of radiographic defect angle on the clinical and radiographic outcomes. Twenty-eight infrabony defects were treated with DFDBA/PRP combination or PRP alone. Clinical parameters and radiographic measurements were compared at baseline and 18 months. Interquartile range was performed to classify the defect angles. Mann-Whitney, Wilcoxon test, and Pearson correlation were used to analyze the data. The DFDBA/PRP combination exhibited more favorable gains in both clinical and radiographic parameters than PRP alone group (p < 0.05). A correlation existed between defect angle, defect depth, and clinical/radiographic outcomes for the defects treated with DFDBA/PRP. The narrow defects presented more favorable clinical attachment level values (CAL) gain, probing pocket depth (PPD) reduction and defect resolution than wide defects in the combination group (p < 0.05). The influence of baseline defect angle was not significant in the PRP-alone group (p > 0.05). The results indicate that DFDBA/PRP combination is more effective than PRP alone for the treatment of infrabony defects, and the amount of CAL gain, PPD reduction, and bone fill increases when the infrabony defect is narrow and deep before DFDBA/PRP combination treatment.

Histomorphometric evaluation of guided bone regeneration around implants with SLA surface: an experimental study in beagle dogs

The aim of this study was to evaluate the efficacy of collagen membranes, either alone or combined with a human demineralized freeze-dried bone allograft (DFDBA) or natural bovine bone graft, in bone defects around dental implants with an SLA (sand-blasted, large grit, acid-etched) surface. The experiments were carried out in three beagle dogs using a split-mouth design. On one side of the jaw, three implants were placed and intra-bony defects were created and covered with a collagen membrane, randomly combined in two of the defects with human DFDBA or inorganic bovine bone graft. A control implant, without membrane covering or defect filling, was also placed. On the other side of the jaw, three implants were placed and the bone defects were treated in a similar fashion, but without membrane covering. The studied variables were the percentage of bone-to-implant contact within the limits of the initial bony defect and percentage of the original bony defect occupied by bone tissue. Although no statistically significant differences were found in this study between the membrane and nonmembrane groups, bone defects augmented with anorganic bovine bone and membranes showed the most promising results from a histological and histomorphometric perspective.

Gene therapeutics for periodontal regenerative medicine

There has been significant advancement in the field of periodontal tissue engineering over the past decade for the repair of tooth-supporting structures. Although encouraging results for periodontal tissue regeneration have been found in numerous clinical investigations using recombinant growth factors, limitations exist with topical protein delivery. Newer approaches seek to develop methodologies that optimize growth factor targeting to maximize the therapeutic outcome of periodontal regenerative procedures. Genetic approaches in periodontal tissue engineering show early progress in achieving delivery of growth factor genes, such as platelet-derived growth factor or bone morphogenetic protein, to periodontal lesions. Ongoing investigations in ex vivo and in vivo gene transfer to periodontia seek to examine the extent of the potential effects in stimulating periodontal tissue engineering.

Position Paper: Periodontal Regeneration

Untreated periodontal disease leads to tooth loss through destruction of the attachment apparatus and tooth-supporting structures. The goals of periodontal therapy include not only the arrest of periodontal disease progression,but also the regeneration of structures lost to disease where appropriate. Conventional surgical approaches (e.g., flap debridement) continue to offer time-tested and reliable methods to access root surfaces,reduce periodontal pockets, and attain improved periodontal form/architecture. However, these techniques offer only limited potential towards recovering tissues destroyed during earlier disease phases. Recently, surgical procedures aimed at greater and more predictable regeneration of periodontal tissues and functional attachment close to their original level have been developed, analyzed, and employed in clinical practice. This paper provides a review of the current understanding of the mechanisms, cells, and factors required for regeneration of the periodontium and of procedures used to restore periodontal tissues around natural teeth. Targeted audiences for this paper are periodontists and/or researchers with an interest in improving the predictability of regenerative procedures. This paper replaces the version published in 1993.

The restoration of anatomic form of atrophied alveolar processes of jaws with the help of bioimplant lioplast

The purpose of the present research was: 1. To investigate the opportunity of application of allogen osteoplastic materials such as Lioplast, received in Samara Tissue Bank of Samara State Medical University. 2. To work out a new technique of producing lyophilized allogen osteoplastic materials, such as Lioplast, with application of an ultrasonic method of clearing. 3. The development of various techniques of operative intervention on jaws for increase in volume of atrophied, as a result of secondary adentia, alveolar shoot. 4. The application of spongy allogen osteoplastic material as a skeleton for filling in surgical operations on jaws. 5. The demonstration of the Technique of a bone-periostic Lioplast 'sandwich' for formation of an alveolar shoot.

Human Periodontal Ligament Cell Sheets Can Regenerate Periodontal Ligament Tissue in an Athymic Rat Model

Conventional periodontal regeneration methods remain insufficient to attain complete and reliable clinical regeneration of periodontal tissues. We have developed a new method of cell transplantation using cell sheet engineering and have applied it to this problem. The purpose of this study was to investigate the characteristics of human periodontal ligament (HPDL) cell sheets retrieved from culture on unique temperature-responsive culture dishes, and to examine whether these cell sheets can regenerate periodontal tissues. The HPDL cell sheets were examined histologically and biochemically, and also were transplanted into a mesial dehiscence model in athymic rats. HPDL cells were harvested from culture dishes as a contiguous cell sheet with abundant extracellular matrix and retained intact integrins that are susceptible to trypsin-EDTA treatment. In the animal study, periodontal ligament-like tissues that include an acellular cementum-like layer and fibrils anchoring into this layer were identified in all the athymic rats transplanted with HPDL cell sheets. This fibril anchoring highly resembles native periodontal ligament fibers; such regeneration was not observed in nontransplanted controls. These results suggest that this technique, based on the concept of cell sheet engineering, can be useful for periodontal tissue regeneration.

Synthetic extracellular matrices for tissue engineering and regeneration

The need for replacement tissues or organs requires a tissue supply that cannot be satisfied by the donor supply. The tissue engineering and regeneration field is focused on the development of biological tissue and organ substitutes and may provide functional tissues to restore, maintain, or improve tissue formation. This field is already providing new therapeutic options to bypass the limitations of organ?tissue transplantation and will likely increase in medical importance in the future. This interdisciplinary field accommodates principles of life sciences and engineering and encompasses three major strategies. The first, guided tissue regeneration, relies on synthetic matrices that are conductive to host cells populating a tissue defect site and reforming the lost tissue. The second approach, inductive strategy, involves the delivery of growth factors, typically using drug delivery strategies, which are targeted to specific cell populations in the tissues surrounding the tissue defect. In the third approach, specific cell populations, typically multiplied in culture, are directly delivered to the site at which one desires to create a new tissue or organ. In all of these approaches, the knowledge acquired from developmental studies often serves as a template for the tissue engineering approach for a specific tissue or organ. This article overviews the development of synthetic extracellular matrices (ECMs) for use in tissue engineering that aim to mimic functions of the native ECM of developing and regenerating tissues. In addition to the potential therapeutic uses of these materials, they also provide model systems for basic studies that may shed light on developmental processes.

In vivo experimental study on bone regeneration in critical bone defects using an injectable biodegradable PLA/PGA copolymer

OBJECTIVES

An assessment was done of the bone-healing rate after implantation of a polylactide/polyglycolide copolymer (PLA-PGA) 50/50 dispersed in aqueous solution of PGA and dextran, used as bone substitutes in an animal model.

STUDY DESIGN

Two groups of 5 rabbits each were used. In both the femoral condyles, a critical size defect of 6x10 mm was made. On the right side PLA/PGA was inserted; the left side remained empty. Thirty and 90 days after surgery the animals were killed.

RESULTS

Defects left unfilled showed no spontaneous healing after 30 and 90 days. Sites filled with experimental materials showed new bone ranging between 11.46% and 76.82% after 30 days, and 75.98% and 95.34% after 90 days. Histomorphometry showed an increase in bone maturation between day 30 and 90 in experimental sites. At day 90, no statistical difference was seen as compared to normal bone.

CONCLUSION

PLA/PGA copolymer dispersed in hydrosoluble matrix seems to be suitable as osteoconductive material in critical size defects.

Favorable Periodontal Regenerative Outcomes From Teeth With Presurgical Mobility: A Retrospective Study

BACKGROUND

The relevance of tooth mobility on periodontal healing is still controversial. The purpose of the present study was to evaluate the effect of presurgical tooth mobility on periodontal regenerative outcomes.

METHODS

The data in this study were derived from three randomized clinical trials which evaluated regenerative procedures. Sixty-four patients with one intraosseous periodontal defect each received one of the following treatments: guided tissue regeneration (GTR) using expanded polytetrafluoroethylene (ePTFE), GTR using a bioabsorbable membrane with or without demineralized freeze-dried bone allograft (DFDBA), or enamel matrix derivative with or without DFDBA. Probing depth (PD), clinical attachment level (CAL), recession (REC), and tooth mobility (TM) were recorded at baseline and 1 year after treatment by a calibrated examiner. The post-surgical follow-up and maintenance periods were designed to optimize plaque control. The teeth were grouped according to their baseline Miller index TM score. The grouping yielded 36 teeth with minimal mobility, score 0; 13 teeth with score 1; and 15 with score 2. The mean changes in PD, CAL and REC from baseline to 1 year were calculated for each group. One-way analysis of variance (ANOVA) was performed to assess differences between the tooth mobility groups considering changes in PD, CAL, and REC at 1 year.

RESULTS

The mean PD reduction from baseline to 1 year for teeth with TM score 0 was 3.67 mm; for TM score 1, 2.81 mm; and for score 2, 3.73 mm. The corresponding values for the gain in CAL were 2.73, 1.96, and 2.36 mm, respectively. According to ANOVA, the probing depth reductions and clinical attachment level gains found in each group were not statistically different, P= 0.218 and P= 0.252, respectively.

CONCLUSION

Within the limitations of this analysis, it can be concluded that interproximal, intraosseous defects of teeth with limited presurgical tooth mobility; i.e., teeth with Miller's Class 1 and 2 mobility, will respond favorably to regenerative therapy.

Guided tissue regeneration in intrabony periodontal defects following treatment with two bioabsorbable membranes in combination with bovine bone mineral graft. A clinical and radiographic study

AIM

Comparison of two bioabsorbable barriers (collagen and polylactic acid (PLA) membranes) combined with a bovine bone mineral (BBM) graft, with an access flap procedure (AFP) alone for treating intrabony defects.

MATERIAL AND METHODS

Thirty-four subjects participated in this prospective, controlled clinical trial. Baseline clinical examination (probing depth (PD), clinical attachment level (CAL)) of selected sites was performed 2 months after completion of conservative treatment in conjunction with hard-tissue measurements to ascertain the depth of the defect (cementoenamel junction to the bottom of the defects). After randomly dividing patients into three groups (two membrane groups, one control group), full thickness flaps were elevated and exposed root surfaces planed before filling defects with bone graft and positioning a barrier membrane covering the defect. The control group was treated identically except for the barrier and bone graft placement. Clinical treatment outcomes were finally evaluated 12 months after surgery for changes of PD and CAL. Radiographs at baseline and 12 months were compared using non-standardized digital radiography.

RESULTS

A mean reduction in PD value of 5.08 mm and mean CAL gain of 4.39 mm occurred in the collagen-BBM group. Corresponding values for the PLA-BBM group were 4.72 and 3.71 mm, while access flap procedure (AFP) sites produced values of 2.50 and 2.43 mm. All improvements in clinical parameters were statistically significant (p<0.001) within groups for all variables. Both membranes produced statistically greater PD reduction and CAL gain compared with AFP treatment (p<0.05). Comparison between barrier groups failed to reveal any statistically significant difference in probing pocket depth reduction (p=0.56) or in CAL gain (p=0.34).

CONCLUSION

Placement of the two barrier membranes used in the present study in combination with BBM graft significantly improved clinical and radiographic parameters of deep intrabony pockets and proved superior to access flap alone.

Influence of Demineralized Bone Matrix's Embryonic Origin on Bone Formation: An Experimental Study in Rats

BACKGROUND

There are results suggesting that differences regarding bone-inducing potential, in terms of amount and/or rate of bone formation, exist between demineralized bone matrices (DBMs) of different embryonic origins.

PURPOSE

The aim of the present study was to examine whether the embryonic origin of DBM affects bone formation when used as an adjunct to guided tissue regeneration (GTR).

MATERIALS AND METHODS

Endomembranous (EM) and endochondral (ECH) DBMs were produced from calvarial and long bones of rats, respectively. Prior to the study the osteoinductive properties of the DBMs were confirmed in six rats following intramuscular implantation. Following surgical exposure of the mandibular ramus, a rigid hemispheric Teflon capsule loosely packed with a standardized quantity of DBM was placed with its open part facing the lateral surface of the ramus in both sides of the jaw in 30 rats. In one side of the jaw, chosen at random, the capsule was filled with EM-DBM, whereas in the other side ECH-DBM was used. Groups of 10 animals were sacrificed after healing periods of 1, 2, and 4 months, and undecalcified sections of the capsules were produced and subjected to histologic analysis and computer-assisted planimetric measurements.

RESULTS

During the experiment increasing amounts of newly formed bone were observed inside the capsules in both sides of the animals' jaws. Limited bone formation was observed in the 1- and 2-month specimens, but after 4 months of healing, the newly formed bone in the ECH-DBM grafted sides occupied 59.1% (range 45.6-74.7%) of the area created by the capsule versus 46.9% (range 23.0-64.0%) in the EM-DBM grafted sides (p =.01).

CONCLUSION

It is concluded that the embryonic origin of DBM influences bone formation by GTR and that ECH-DBM is superior to EM-DBM.

Comparison of Porous and Non-Porous Teflon Membranes Plus a Xenograft in the Treatment of Vertical Osseous Defects: A Clinical Reentry Study

BACKGROUND

The primary aim of this 9-month randomized, controlled, blinded, clinical reentry study was to compare the regenerative effects of a nonporous polytetrafluoroethylene (NP) periodontal membrane to a porous expanded polytetrafluoroethylene (P) periodontal membrane in the treatment of vertical osseous defects.

METHODS

Twenty-four patients, 11 males and 13 females, age 24 to 74 (mean 50.5 +/- 13.1) provided one site with an intraosseous defect > or = 4 mm and were divided equally and randomly into two groups. Following debridement both groups were grafted with a bovine-derived xenograft coated with a synthetic cell-binding peptide; then the test group received an NP membrane and the control group received a P membrane. All defects were reentered after 9 months. Measurements were performed by a masked examiner.

RESULTS

There were no statistically significant differences (P>0.05) between NP and P groups for any open or closed probing measurement at any time. Similar open initial defect depth for the NP group and P groups (4.8 versus 5.0 mm) demonstrated identical 9-month defect fill of 2.8 mm (57%) for both groups. A difference in crestal resorption for the NP compared to the P group (0.4 versus 0.8 mm) accounted for the difference in mean percent defect resolution, which was 67% for NP compared to 72% for the P group. Overall, nine (75%) of the NP group defects and eight (67%) of the P group defects showed more than 50% defect fill.

CONCLUSION

Treatment of vertical osseous defects with nonporous or porous polytetrafluoroethylene membranes in combination with a xenograft resulted in statistically significant improvement in open and closed probing measurements, with no significant difference between treatment groups.

Deproteinized bovine bone and gentamicin as an adjunct to GTR in the treatment of intrabony defects: a randomized controlled clinical study

OBJECTIVES

To evaluate whether Bio-Oss used as an adjunct to guided tissue regeneration (GTR) improves the healing of 1- or 2-wall intrabony defects as compared with GTR alone, and to examine whether impregnation of Bio-Oss with gentamicin may have an added effect.

MATERIAL AND METHODS

Sixty patients, with at least one interproximal intrabony defect with probing pocket depth (PPD) > or =7 mm and radiographic evidence of an intrabony component (IC) > or =4 mm, were treated at random with either a resorbable membrane (GTR), a resorbable membrane in combination with Bio-Oss impregnated with saline (DBB-), a resorbable membrane in combination with Bio-Oss impregnated with gentamicin (DBB+), or with flap surgery (RBF).

RESULTS

All treatment modalities resulted in statistically significant clinical improvements after 1 year. Defects treated with GTR alone presented a probing attachment level (PAL) gain of 2.9 mm, a residual PPD (PPD12) of 4.9 mm, a radiographic bone level (RBL) gain of 3.1 mm, and a residual IC (IC12) of 2.7 mm. GTR combined with Bio-Oss did not improve the healing outcome (PAL gain: 2.5 mm; PPD12: 4.9 mm; RBL gain: 2.8 mm; IC12: 3.3 mm). Impregnation of the Bio-Oss with gentamicin 2% mg/ml resulted in clinical improvements (PAL gain: 3.8 mm; PPD12: 4.2 mm; RBL gain: 4.7 mm; IC12: 2.1 mm), superior to those of the other treatment modalities, but the difference was not statistically significant. Defects treated with only flap surgery showed the most inferior clinical response (PAL gain: 1.5 mm; PPD12: 5.1 mm; RBL gain: 1.2 mm; IC12: 4.2 mm) of all groups.

CONCLUSION

The results failed to demonstrate an added effect of Bio-Oss implantation in combination with GTR on the healing of deep interproximal 1- or 2-wall, or combined 1- and 2-wall intrabony defects compared with GTR alone. Local application of gentamicin, on the other hand, improved the treatment outcome but not to an extent that it was statistically significant.

Defect-determined regenerative options for treating periodontal intrabony defects in baboons

BACKGROUND

In an effort to regenerate periodontal intrabony defects, the healing potential of the defect should determine what therapeutic modalities and materials are employed. The purpose of this study was to compare regenerative outcomes in baboon intrabony defects that were contained versus non-contained, using various regenerative therapies.

METHODS

Nine adult baboons (Papio anubis) in good health were treated. Eighty-six interproximal, intrabony defects were surgically created: 43 contained by 3 walls of bone; 43 non-contained with a missing buccal wall. Chronicity and plaque accumulation were encouraged with wire ligature placement for 8 weeks. After ligature removal, scaling, and a 2- to 4-week healing period, the defects were treated with the following therapies: collagen membrane (GTR), human demineralized freeze-dried bone (DFDB) grafting (BG), combined therapy (GTR + BG) and a DFDB-glycoprotein sponge matrix (MAT). Clinical healing responses were evaluated in 58 sites by changes in soft tissue (recession, probing, clinical attachment) and hard tissue (resorption, defect fill) parameters 6 months post-treatment. Histologic evaluation (defect regeneration, connective tissue attachment, epithelial migration) was done on 26 sites.

RESULTS

For contained defects, no real significant clinical (ANOVA) or histologic differences existed among treatments. However, for non-contained defects, combined therapy (GTR + BG) demonstrated clinically significant (P < or = 0.05, ANOVA) and histologically superior healing results over the other therapies tested.

CONCLUSION

These results confirm a defect morphology directed rationale for periodontal intrabony therapy.

Characterization of bone defect repair in young and aged rat femur induced by xenogenic demineralized bone matrix

BACKGROUND

The osteoinductive effect of some biomaterials could be affected by those systemic conditions typical of old age. The aim of the present paper was to assess the effects of age on the healing of bone defects treated with demineralized bone matrix (DBM).

METHODS

The study was conducted in young (3 month old) and aged (18 month old) rats to assess the efficacy of DBM in the treatment of osseous defects in bone with limited repair capacities. A standard bone defect was created in the distal femoral condyles of male Wistar rats: the left condyle was filled with rabbit DBM granules, while the right condyle was left empty (control). Histological and microhardness analyses were performed at 30 and 45 days after implant surgery.

RESULTS

After implantation of xenogenic DBM, bone healing areas of the aged and young groups showed a significant increase in the formation of newly mineralized bone relative to controls. Measurements of trabecular thickness on day 45 revealed no differences between newly formed and preexisting bone in the young group, while control values were lower. Microhardness measurements demonstrated that newly mineralized bone, either induced by DBM or not, and preexisting bone were comparable in terms of trabecular hardness after 45 days.

CONCLUSIONS

In conclusion, xenogenic DBM seems to be effective in bone defect healing, since it increases mineralized tissue volume. In both DBM-filled and empty sites, age seems to have a detrimental effect on the volume of new bone formation but no influence on bone maturation.

Platelet-rich plasma and bovine porous bone mineral combined with guided tissue regeneration in the treatment of intrabony defects in humans

BACKGROUND

A combination of platelet-rich plasma (PRP), bovine porous bone mineral (BPBM) and guided tissue regeneration (GTR) has been shown to be effective in promoting clinical signs of periodontal regeneration in intrabony defects. As an initial attempt to clarify the role played by each of the three treatment components, this study was performed to compare the clinical effectiveness of two regenerative techniques for intrabony defects in humans: a combination of PRP/BPBM/GTR vs. GTR.

MATERIAL AND METHODS

Eighteen patients participated in the study. Using a split-mouth design, interproximal bony defects were surgically treated with either an absorbable membrane made of polylactic acid for GTR or a combination of PRP/BPBM/GTR. Changes in pocket depth, attachment level and defect fill as revealed by 6-month reentry surgeries were evaluated.

RESULTS

Both treatment modalities resulted in significant pocket depth reduction and clinical attachment gain as compared to baseline values. Pocket depth reduction was 4.98 +/- 0.96 mm on buccal and 4.93 +/- 0.92 mm on lingual sites of the PRP/BPBM/GTR group and 3.62 +/- 0.81 mm on buccal and 3.54 +/- 0.88 mm on lingual sites of the GTR group. The gain in clinical attachment observed was 4.37 +/- 1.31 mm on buccal and 4.28 +/- 1.33 mm on lingual sites of the PRP/BPBM/GTR group and 2.62 +/- 1.23 mm on buccal and 2.44 +/- 1.21 mm on lingual sites of the GTR group. The amount of defect fill observed was 4.78 +/- 1.26 mm on buccal and 4.66 +/- 1.32 mm on lingual sites of the PRP/BPBM/GTR group and 2.31 +/- 0.76 mm on buccal and 2.26 +/- 0.81 mm on lingual sites of the GTR group. All differences between the two groups were statistically significant in favor of the PRP/BPBM/GTR group.

CONCLUSIONS

The results of this study suggest that PRP and BPBM provide an added regenerative effect to GTR in promoting the clinical resolution of intrabony defects on patients with severe periodontitis.