Assessment of guided tissue regeneration procedures in intrabony defects with bioabsorbable and non-resorbable barriers

Evaluation of PRF and PLA-PGA Membrane Along with Hydroxyapatite Crystal Collagen Fibers Bone Graft in the Treatment of Infrabony Defects

AIM

The present study was carried out to compare the effectiveness of leukocyte platelet-rich fibrin (L-PRF) membrane and polylactic acid-polyglycolic acid (PLA-PGA) membrane along with hydroxyapatite crystal collagen fibers bone graft in the treatment of human infrabony defects using cone beam computed tomography.

MATERIALS AND METHODS

A total of 28 systemically healthy patients was chosen which were found appropriate after initial therapy. Each group comprises of 14 defects, according to randomized parallel design. The group A was managed by hydroxyapatite crystal collagen fibers bone graft in conjunction with L-PRF membrane, while group B was treated by hydroxyapatite crystal collagen fibers bone graft in conjunction with PLA-PGA membrane. Clinical and radiographic measurements were recorded at baseline and 6 months postoperatively.

RESULTS

Statically significant difference was seen in mean probing pocket depth (PPD), mean R-CAL, and DD from baseline to 6 months in group A and group B but there was no statically significant difference in mean PPD reduction (0.35 ± 1.90 mm), mean R-CAL gain (0.28 ± 1.85 mm) and DD reduction (0.12 ± 1.42 mm) seen at 6 months when compared between both the groups.

CONCLUSION

At 6 months post-surgery both treatment modalities demonstrated statistically significant improvements with regards to CAL gains, PPD reduction, and reduction in radiographic defect depth.

CLINICAL SIGNIFICANCE

Platelet-rich fibrin (PRF) membrane and PLA-PGA membrane along with hydroxyapatite crystal collagen fibers bone graft are useful in the treatment of infrabony defect. Platelet-rich fibrin membrane with hydroxyapatite crystal collagen fibers bone graft have shown to be better in regeneration of bony defect as PRF membrane has growth factors which help in bone regeneration.

Effect of Different Membranes on Vertical Bone Regeneration: A Systematic Review and Network Meta-Analysis

This study is aimed at performing a systematic review and a network meta-analysis of the effects of several membranes on vertical bone regeneration and clinical complications in guided bone regeneration (GBR) or guided tissue regeneration (GTR). We compared the effects of the following membranes: high-density polytetrafluoroethylene (d-PTFE), expanded polytetrafluoroethylene (e-PTFE), crosslinked collagen membrane (CCM), noncrosslinked collagen membrane (CM), titanium mesh (TM), titanium mesh plus noncrosslinked (TM + CM), titanium mesh plus crosslinked (TM + CCM), titanium-reinforced d-PTFE, titanium-reinforced e-PTFE, polylactic acid (PLA), polyethylene glycol (PEG), and polylactic acid 910 (PLA910). Using the PICOS principles to help determine inclusion criteria, articles are collected using PubMed, Web of Science, and other databases. Assess the risk of deviation and the quality of evidence using the Cochrane Evaluation Manual, and GRADE. 27 articles were finally included. 19 articles were included in a network meta-analysis with vertical bone increment as an outcome measure. The network meta-analysis includes network diagrams, paired-comparison forest diagrams, funnel diagrams, surface under the cumulative ranking curve (SUCRA) diagrams, and sensitivity analysis diagrams. SUCRA indicated that titanium-reinforced d-PTFE exhibited the highest vertical bone increment effect. Meanwhile, we analyzed the complications of 19 studies and found that soft tissue injury and membrane exposure were the most common complications.

Evaluation of effectiveness of hyaluronic acid in combination with bioresorbable membrane (poly lactic acid-poly glycolic acid) for the treatment of infrabony defects in humans: A clinical and radiographic study

Background:

The combination of biomaterials, bone graft substitutes along with guided tissue regeneration (GTR) has been shown to be an effective modality of periodontal regenerative therapy for infrabony defects. Therefore, the present randomized controlled clinical study was undertaken to evaluate the effectiveness of hyaluronic acid (HA) in combination with bioresorbable membrane for the treatment of human infrabony defects.

Materials and Methods:

Twenty four infrabony defects in 20 systemically healthy patients were randomly assigned to test (HA in combination with bioresorbable membrane) and control (bioresorbable membrane alone) treatment groups. Probing pocket depth (PPD), relative attachment level, and relative gingival margin level were measured with a computerized Florida disc probe at baseline and at 6 months follow-up. Radiographic measurements were also evaluated at baseline and at 6 months of postsurgery.

Results:

At 6 months, the mean reduction in PPD in test group and control group was 4.52 mm and 2.97 mm, respectively. Significantly higher clinical attachment level with a gain of 2.20 mm was found in the test group as compared to control group. In addition, statistically significant greater reduction of radiographic defect depth was observed in the test group.

Conclusion:

Regenerative approach using hyaloss in combination with GTR for the treatment of human infrabony defects resulted in a significant added benefit in terms of CAL gains, PPD reductions and radiographic defect fill, as well as LBG, compared to the GTR alone.

Do the clinical effects of enamel matrix derivatives in infrabony defects decrease overtime? A systematic review and meta-analysis

Previous systematic reviews have demonstrated better results with enamel matrix derivative proteins (EMDP) as compared with open flap debridement (OFD) for the management of infrabony periodontal defects (IPD). The aim of this study was to determine whether these differences vary according to the follow-up and quality of the studies. Cochrane Central Register of Controlled Trials, Medline/PubMed, Lilacs, Embase and Web of Science electronic databases were searched up to August 2013 for randomized clinical trials.Eligible outcomes were changes in probing depth (PD), clinical attachment level (CAL),gingival recession (GR) and bone changes (BC). Studies with follow-up of 12 months showed differences of 0.97 mm (CI95% 0.52 - 1.43) and 1.19 mm (CI95% 0.77 - 1.60) for PD and CAL, respectively, favorable for EMDP. Studies with follow-up ≥ 24 months presented advantages of 1.11 mm (CI95% 0.74 -1.48) for CAL and 0.83 mm (CI95% 0.19 -1.48) for PD,with use of EMDP. Considering the quality of studies, those with low risk of bias showed lower difference between groups, presenting 0.8 mm (CI95% 0.24-1.36) for CAL, favorable for EMDP and without differences for PS (0.51 mm, CI95% -0.21 - 1.23). In conclusion, follow-up time (< or > 2 years) and the risk of bias influence the results of treatment with EMDP in IPD.

Peri-implant diseases: an overview

The use of dental implants in replacing missing teeth is proven to be a valid treatment with a high success rate. To achieve the best treatment outcome in all implant systems, the implant has to be able to integrate with the surrounding tissue. However, dental implants are affected by peri-implant diseases and may fail as a result. As the number of implants placed continues to increase, the prevalence of peri-implant disease will also increase. This requires preventive measures to inhibit the development of the disease and stop its progression. Clinical Relevance: Understanding how to maintain healthy peri-implant tissue as well as diagnosis and treatment of disease are vital for every dentist and dental student.

Mandibular tori as bone grafts: an alternative treatment for periodontal osseous defects - clinical, radiographic and histologic morphology evaluation

OBJECTIVES

The present study was designed to evaluate the clinical, radiographic and histochemical significance of using the mandibular tori as autogenous bone graft for treatment of intraosseous defects in patients with chronic periodontitis.

MATERIALS AND METHODS

Twenty-eight sites from 14 patients with chronic periodontitis were included in this study. Each patient was treated with split mouth design; one site received torus mandibularis bone graft and the other site received a full-thickness fap alone. Histopathologic assessment was evaluated on removal of torus mandibularis to evaluate its histologic structure and by the end of the study 9 month later. Clinical and radiographic parameters were re-evaluated at 3 months interval for 1 year.

RESULTS

The results of the present study revealed significant gain in the clinical attachment level (CAL) (88.4%, 4.53 ± 0.06 mm) for torus mandibularis sites compared to (39.7%, 2.01 ± 0.04 mm) for full-thickness fap. Moreover, there was a reduction in the probing pocket depth (PPD) of (75.4%, 5.75 ± 0.12 mm) for torus mandibularis sites and (49.6%, 3.73 ± 0.14 mm) for sites treated with a full-thickness fap only; CAL and PPD differences were significant at p-value ≤0.01. Concomitantly, significant radiographic increase in the bone height and density were recorded in the test group.

CONCLUSION

The use of mandibular tori as autogenous bone graft could provide benefits as a periodontal therapeutic modality and enhance regenerative potential of periodontal intraosseous defects.

Periosteum as a barrier membrane in the treatment of intrabony defect: A new technique

OBJECTIVE

The purpose of the study was to evaluate the clinical effectiveness of periosteum as a barrier membrane for the treatment of intrabony defects.

MATERIALS AND METHODS

The study was conducted in patients having bilateral intrabony defects. A total of 20 intrabony defects in 10 patients were treated, out of which 10 defects received periosteal barrier and the other 10 defects received conventional open flap debridement procedure. The efficacy of the treatment was assessed using clinical parameters and dentascan.

RESULTS

Statistically significant gain in clinical attachment level (CAL) was found in the test group (2.00 ± 0.26 mm) as compared to the control group (0.60 ± 0.22 mm). In both the treatment modalities (test and control groups), a significant decrease in probing pocket depth of 3.90 ± 0.35 mm and 2.90 ± 0.31 mm was observed, respectively. The difference between the two groups was not statistically significant. Bone defect fill was 1.40 ± 0.16 mm for the test group and 0.90 ± 0.18 mm for the control group, but the difference observed was not statistically significant.

CONCLUSION

The results of this study show that periosteal barrier membrane can be a better alternative of barrier membranes for the treatment of intrabony defects.

Biocompatibility and cytotoxic evaluation of drug-loaded biodegradable guided tissue regeneration membranes

BACKGROUND

In periodontology, Guided Tissue Regeneration (GTR) is based on the concept of providing a space for entry of cells with regenerative potential into the wound environment to initiate the regeneration of structures lost due to periodontal disease. First generation GTR membranes were primarily non-absorbable membranes like expanded polytetrafluorethylene which required a second surgery for its removal. This led researchers to explore absorbable materials like collagen and synthetic biodegradable polymers to fabricate GTR membranes. In the present study, biodegradable Polylactic acid (PLA) is used to fabricate membranes with the potential to be used for GTR therapy.

MATERIALS AND METHODS

Biocompatibility of the PLA membranes were evaluated in a subcutaneous guinea pig model. Antimicrobial effect of the drug-loaded PLA membranes were assessed against a drug-resistant Staphylococcus aureus bacterial isolate. The cytocompatibility of the drug-loaded membranes were evaluated using HeLa cell lines.

RESULTS

The PLA membranes were shown to be biocompatible. The drug-loaded PLA membranes showed significant activity against the bacterial isolate. Among the drug-loaded membranes, tetracycline-loaded membrane showed minimal cellular toxicity.

CONCLUSION

The results of this study indicate that biodegradable drug-releasing polylactide membranes have the potential to be used for periodontal regeneration. It has the necessary characteristics of a GTR membrane like biocompatibility, space maintaining ability, and tissue integration. Among the various antimicrobial agents loaded in the PLA membranes, tetracycline-loaded membranes exhibited minimal cellular toxicity against HeLa cells; at the same time showing significant activity against a pathogenic bacterium.

A clinical comparison of autogenous bone graft with and without autogenous periodontal ligament graft in the treatment of periodontal intrabony defects

The aim of the present study was to evaluate the efficacy of autogenous bone graft (ABG) with and without autogenous periodontal ligament graft (PDLG) in the management of human two-wall intrabony periodontal defects. Twenty-six similar two-wall intrabony periodontal defects with >or=5 mm probing depths and >or=3 mm depths of intrabony component in 13 nonsmoking healthy patients were selected. One defect in each subject was treated with ABG alone (ABG group) and the contralateral one with ABG and PDLG (PDLG group). The primary outcomes of the study included changes in clinical probing depth (CPD) and clinical attachment level (CAL). Groups showed statistically significant improvements in soft and hard tissue parameters after 6 months. However, the between-group differences after 6 months were not statistically significant with regard to soft and hard tissue measurements except CAL gain. In the combined group, it was significantly higher than the ABG group (3.69 and 2 mm, respectively; P = 0.03). Within the limits of this study, both treatments resulted in marked clinical improvement, but combined treatment seemed to enhance the results in the treatment of two-wall intrabony defects.

Stability of Clinical and Radiographic Results After Guided Tissue Regeneration in Infrabony Defects

BACKGROUND

The aim of this 5-year follow-up study was to evaluate clinically and radiographically the long-term results after guided tissue regeneration (GTR) therapy of infrabony defects using non-resorbable and bioabsorbable barriers.

METHODS

Thirty-one patients with periodontitis and 50 infrabony defects that had been treated using GTR were recruited. Eleven defects were treated with non-resorbable expanded polytetrafluoroethylene membranes and 39 defects with bioabsorbable barriers. At baseline and 6 and 60 +/- 3 months after surgery, clinical parameters and standardized radiographs were obtained. During surgery and 60 +/- 3 months thereafter, the distance from the cemento-enamel junction to the base of the bony defect (vertical probing bone level [PBL-V]) was measured. Bone gain was evaluated using digital subtraction radiography.

RESULTS

At 6 and 60 +/- 3 months after GTR, there was a statistically significant (P <0.001) reduction of probing depth (6 months: 4.31 +/- 1.76 mm; 60 months: 3.95 +/- 1.62 mm) and vertical clinical attachment level gains (CAL-V) (6 months: 3.34 +/- 1.66 mm; 60 months: 2.97 +/- 1.53 mm). From 6 to 60 months after GTR, three infrabony defects exhibited CAL-V loss >2 mm, and a small, statistically not significant mean CAL-V loss of 0.39 +/- 1.60 mm was observed. From baseline to 60 +/- 3 months, a significant PBL-V gain of 1.78 +/- 2.67 mm (P <0.001) and increase in bone density were observed (P = 0.003).

CONCLUSION

The CAL-V gain achieved after GTR in infrabony defects using both non-resorbable and bioabsorbable barriers was stable after 5 years in 47 of 50 defects.

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.

Treatment of Wide, Shallow, and Predominantly 1-Wall Intrabony Defects With a Bioabsorbable Membrane: A Randomized Controlled Clinical Trial

BACKGROUND

The regenerative therapy of non-contained intrabony defects achieves better results when bioabsorbable membranes are combined with a filling material. The purpose of the present study was to analyze clinical and radiographic effectiveness of a space-making bioabsorbable membrane in the treatment of wide and shallow intrabony defects characterized by a relevant 1-wall component.

METHODS

Eighteen pairs of angular bone defects were selected in 18 healthy, non-smoking patients (age range 30 to 66 years). Prior to the surgical phase, patients were enrolled in a strict periodontal program including oral hygiene instructions and scaling and root planing (presurgical full-mouth plaque score <10%). Using a split-mouth design, 18 sites were randomly assigned to receive guided tissue regeneration (GTR) using a bioabsorbable membrane (test group) and 18 to receive open flap debridement alone (control group). Clinical treatment outcome was evaluated 12 months postoperatively for changes in probing depth (PD), clinical attachment level (CAL), and position of gingival margin (REC) and radiographically for bone changes.

RESULTS

Open flap debridement and GTR yielded statistically significant (P<0.0001) PD reduction (2.39+/- 0.92 mm and 3.44+/- 0.78 mm), CAL gain (1.50+/- 0.99 mm and 2.89 +/- 0.90 mm), increased REC (-0.89 +/- 0.58 mm and -0.56 +/- 0.92 mm) and bone fill (1.05+/- 0.94 mm and 2.13+/- 1.21 mm) when 12-month data were compared to baseline. The differences between test and control groups were statistically significant for all parameters (P<0.007) except for REC (P=0.25).

CONCLUSION

The use of this bioabsorbable membrane would seem to be effective in the treatment of intrabony defects with unfavorable architecture without the use of filling materials.

The combined use of enamel matrix proteins and a tetracycline-coated expanded polytetrafluoroethylene barrier membrane in the treatment of intra-osseous defects

OBJECTIVES

The purpose of this split-mouth study was to evaluate the clinical response of enamel matrix proteins (EMPs, Emdogain Gel in intra-osseous defects with or without a combined application of a tetracycline-coated expanded polytetrafluoroethylene barrier membrane (e-PTFE, Gore-Tex).

METHODS

Twelve pairs of intra-osseous periodontal defects in 11 patients received the application of EMPs on the exposed root surface (EMP). One of the two defects received randomly, as an adjunct to EMP treatment, a tetracycline-coated e-PTFE membrane (MEMP). At baseline, 6- and 12-month probing pocket depth (PPD), clinical attachment level (CAL) and probing bone level (PBL) were measured.

RESULTS

After 12 months, the EMP defects showed a significant mean PPD reduction of 2.86+/-0.75 mm, a mean gain in CAL of 1.28+/-2.04 mm, a mean PBL gain of 1.63+/-1.21 mm and a mean increase of recession (REC) of 1.56+/-2.30 mm. The MEMP defects showed a significant mean PPD reduction of 3.02+/-1.55 mm, a mean gain in CAL of 1.65+/-1.29 mm, a mean PBL gain of 1.58+/-1.92 mm and a mean increase of REC of 1.38+/-1.63 mm. Except for significantly more post-operative discomfort at the MEMP sites, no significant differences were found between EMP and MEMP defects.

CONCLUSION

Within the limits of this study, it is concluded that in the treatment of intra-osseous defects with EMP, the adjunctive use of a tetracycline-coated e-PTFE membrane failed to show more gain of CAL and PBL.

A novel bioabsorbable composite membrane of Polyactive® 70/30 and bioactive glass number 13-93 in repair of experimental maxillary alveolar cleft defects

A novel bioabsorbable composite membrane of polyethylene oxide terephthalate and polybutylene terephthalate copolymer (Polyactive 70/30) combined with bioactive glass No. 13--93 was tested in the repair of experimental maxillary alveolar cleft defects. In this pilot study, the possible ability of the membrane to promote bone formation by guided tissue regeneration was investigated. Standard alveolar defects were made bilaterally in the maxilla of 12 growing rabbits and were filled with autogenous bone grafts. The test defect was covered with the composite membrane and the other defect was left uncovered to serve as a control. The follow-up time was 10 weeks. Radiological, histological, and histomorphometric evaluations were performed. Radiologically, no statistically significant differences between test and control defects at 10 weeks were found. Histologically, the membrane enhanced osteogenic activity locally at the membrane-bone interface. Swelling of the membrane was observed. Histomorphometrically, no significant promotion of bone formation by the membrane was observed. The composite membrane was found to be biocompatible and surgically easy to use, but its osteopromotive effect was limited in this experimental cleft model. Further studies are necessary to assess its suitability for reconstructive surgical applications.

Guided Tissue Regeneration Using A Bioabsorbable Membrane: A 21-Case Series

BACKGROUND

The purpose of this paper is to demonstrate how a bioabsorbable membrane in the treatment of intrabony defects, combined with appropriate case selection, produces a significant improvement in the clinical assessment of affected teeth. This study demonstrates success in 21 successive cases.

METHODS

Consecutive patients presenting advanced intrabony defects (8 to 15 mm) meeting the predetermined criteria were treated by guided tissue regeneration (GTR) with flap debridement and placement of a bioabsorbable copolymer membrane. To evaluate treatment predictability in a variety of patients, only one defect per patient was included in the study. Twenty-one patients completed the study, which included baseline measurement and subsequent surgical reentry of the treated site 9 to 18 months postoperatively. Selection of lesions was made following debridement of the defect; i.e., a membrane was placed only after determining that a lesion was a proper candidate for this procedure. Measurements from the cemento-enamel junction (CEJ) to the deepest apical aspect of the defects were made and documented with photographs. At the time of reentry, defect depths were again measured from the CEJ to the deepest apical point along with measurements of the residual 3-walled component of the defect, and photographs were taken. The re-entry procedure involved an apically positioned and occasionally minor osteoplasty to reduce residual probing depth, when present. Radiographs were taken at baseline and reentry.

RESULTS

The initial mean defect depth, as measured from the CEJ to the base of the lesion, was 10.2 mm. The mean defect depth at the time of reentry was 5 mm. The mean gain in vertical bone fill was 5.2 mm. Perhaps more significantly, in 20 of 21 cases, there was vertical fill to within 1 mm of the 3-walled component of the residual defect.

CONCLUSION

When appropriate case selection and management are applied, the use of bioabsorbable membranes does provide for consistent and predictable bone fill, producing clinically relevant reduction in vertical defect depth.

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.

Evaluation of a poly-l-lactic acid membrane and membrane fixing pin for guided tissue regeneration on bone defects in dogs

OBJECTIVES

The purpose of the study was to clarify the usefulness of a poly-l-lactic acid and membrane fixing pin, used in combination with guided bone regeneration, on bone defects in dogs.

STUDY DESIGN

Osteotomies bone defects were created in 8 beagle dogs. Group I: one defect was covered with test membrane and held by fixing pins. Group II: the other defect was covered test membrane and not held by fixing pins. The control group received no membrane. The dogs were killed after 24 or 36 weeks of healing. Sections were stained and evaluated microscopically. Data were analyzed statistically.

RESULTS

The degradation and resorption of test membrane was not observed at 24 weeks but was noted at 36 weeks. After 24 and 36 weeks, most of Group I defects were completely closed with new bone, while in the control defects, only a small amount of new bone was observed at the bottom of the bone defects. After 36 weeks, the percentage of new bone volume (62.2%) in the space beneath the test membrane and membrane fixing pin (Group I) was greater than that without a membrane fixing pin-53.2% (Group II), whereas only 43.9% of the defect area in the control group was filled with new bone.

CONCLUSION

The results of this study show that a poly-l-lactic acid membrane and membrane fixing pin permit bone regeneration that can be ensured by excluding surrounding soft tissues from the wound area.

Wound healing of degree III furcation involvements following guided tissue regeneration and/or Emdogain®

BACKGROUND

The use of enamel matrix proteins (EMD) has been recently introduced as a new treatment alternative for periodontal regeneration. However, no histological studies are available investigating the effect of EMD in the treatment of degree III furcation involvements.

OBJECTIVES

The aim of this study was to evaluate the healing of mandibular degree III furcation involvements histologically following treatment with guided tissue regeneration (GTR), EMD and a combination of EMD and GTR.

MATERIAL AND METHODS

Degree III furcation involvements were surgically created at the teeth 36, 37, 46, 47 in three monkeys (Macaca fascicularis). Spontaneous healing of the defects was prevented by placing impression material into the defects. After 6 weeks, full-thickness flaps were elevated at the buccal and lingual aspect of the experimental teeth. Following removal of all granulation tissue from the furcation defects, scaling/root planing and conditioning of the root surfaces with 24% EDTA gel, the defects were treated with one of the following treatment modalities: (i) EMD, (ii) GTR or (iii) a combination of EMD and GTR. The defects serving as control did not receive any treatment, except from complete coverage with coronally displaced flaps. After 5 months of healing, the animals were killed and perfused with 10% buffered formalin for fixation. The experimental teeth with surrounding tissues were dissected free, decalcified in EDTA, dehydrated and embedded in paraffin. 8 microm thick histological sections were cut and stained and subsequently examined under the light microscope.

RESULTS

The histological analysis revealed that with GTR or combined EMD and GTR treatment, new attachment formation (new cementum with inserting collagen fibers) had occurred on almost the entire circumference of the furcation and new bone was almost filling the defect in the situations where the membrane was not exposed. The sites treated only with EMD exhibited new attachment and new bone formation to a varying extent, while the control sites presented only limited new attachment and bone formation.

CONCLUSION

The results provided histological evidence suggesting that both GTR and EMD may result in true periodontal regeneration, and suggest that this type of healing might be favored by such treatments in comparison with flap surgery.

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.

Comparison of infrabony defects treated with enamel matrix derivative versus guided tissue regeneration with a nonresorbable membrane

AIM

The purpose of the present multicenter clinical trial was to compare the efficacy of two different procedures in the treatment of infrabony defects: guided tissue regeneration (GTR) with nonresorbable membranes and enamel matrix derivative (EMD).

MATERIAL AND METHODS

Six centers participated in this study. Ninety-eight patients with an interproximal infrabony defect were selected. All patients were treated with an initial phase of scaling and root planing, and at the study's baseline the selected defects presented a value of probing depth (PD) > or =6 mm with an infrabony component > or =4 mm. Forty-nine patients were treated with GTR procedures (using ePTFE membranes (Gore-Tex W.L. Gore and Associates, Flagstaff, AZ, USA)) and forty-nine with EMDs (Emdogain (U Biora AB Malm, Sweden)). The efficacy of each treatment modality was investigated through covariance analysis.

RESULTS

The patients were reevaluated at one year postop. Probing attachment level (PAL) gain and PD reduction were analyzed. In the Emdogain group the PAL before surgery (PAL 0) and the PD before surgery (PD 0) were respectively 9.9+/-1.4 and 8.5+/-1.6 mm. The PAL gain and the PD reduction at 1 year postsurgery were respectively 4.1+/-1.8 and 5.3+/-1.9 mm. The group of patients treated with membranes showed that PAL 0 and PD 0 were respectively 8.9+/-1.9 and 8.1+/-1.9. The PAL gain was 4.3+/-1.9 mm and the PD reduction was 5.6+/-1.5 mm. The mean PAL gain expressed by percentage (PAL gain/PAL 0) for the group treated with EMD was 41%, while it was 48% for the group treated with GTR. Results from our analysis suggest that there is no statistically significant difference between GTR and EMD treatments in terms of PAL gain, PD reduction and recession variation. Applying the regression model to a group of patients with a PAL 0 > or =8 mm, we observed a better clinical outcome in terms of PAL gain (difference of 0.3 mm) in patients treated with the GTR procedure compared to those treated with EMD. Covariance analysis showed a strong correlation in both groups of patients between PAL gain and full mouth bleeding score, and between PAL gain and defect morphology and depth.

Guided tissue regeneration in intrabony defects using an experimental bioresorbable polydioxanon (PDS) membrane. A 24-month split-mouth study

AIM

The comparison of the clinical, radiographic, and microbiological healing results in deep intrabony defects following GTR therapy with two different bioresorbable membranes in a prospective split-mouth design.

MATERIAL AND METHODS

31 pairs of contralateral intrabony defects were randomly treated with either an experimental Polydioxanon (PDS) membrane or a Polylactic acid (PLA) matrix barrier. After 6, 12 and 24 months, healing results were assessed using clinical examinations (REC, PPD, CAL, vertical relative attachment gain V-rAG), quantitative digital subtraction radiography (amount and area of bone density changes), and microbiological analysis.

RESULTS

Postoperative membrane exposures occurred in 14 PDS and 2 PLA treated sites. 6, 12 and 24 months p.o., both membranes provided a significant gain in CAL [median values: 6 months (PDS vs. PLA: 3.0 vs. 3.0 mm); 12 and 24 months (PDS vs. PLA: 4.0 vs. 4.0 mm)], which corresponded to a V-rAG of 57.1% (PDS) vs. 62.5% (PLA) after 24 months. PDS and PLA treated sites revealed significant bone density gain 6, 12 and 24 months after surgery. 38.8% (PDS) vs. 41.8% (PLA) of the initial defect areas showed bone density gain. While the gain in bone density was significantly greater in PDS than in PLA sites, neither CAL gain nor the area of bone density changes revealed significant differences. Microbiological culture revealed similar bacterial loads in PDS and PLA sites during the first 12 months.

CONCLUSION

This 24-month study indicates that the PDS and PLA membranes can provide similar favorable regeneration results in deep intrabony periodontal defects, although considerably more postoperative membrane exposures have to be expected in PDS treated sites.

Long-term results of guided tissue regeneration therapy with non-resorbable and bioabsorbable barriers. II. A case series of infrabony defects

BACKGROUND

The aim of this 5-year follow-up case series was to clinically and radiographically evaluate the long-term results after guided tissue regeneration (GTR) therapy of infrabony defects using non-resorbable and bioabsorbable barriers.

METHODS

In 12 patients with advanced chronic periodontitis 12 pairs of contralateral infrabony defects were treated. Within each patient one defect received a non-resorbable (expanded polytetrafluoroethylene [ePTFE]; control: C) and the other a bioabsorbable (polyglactin 910; test: T) barrier by random assignment. At baseline and at 6 and 60 +/- 3 months after surgery clinical parameters and standardized radiographs were obtained. Gain of bone density within infrabony defects was assessed using subtraction radiography.

RESULTS

Eight of 12 patients were available for the 60-month reexaminations. Six and 60 +/- 3 months after GTR therapy statistically significant (P < 0.05) vertical attachment (CAL-V) gain was observed in both groups (C6:2.6 +/- 1.4 mm; C60: 1.6 +/- 1.5 mm; T6:3.0+/- 1.7 mm; T60: 3.0 +/- 0.7mm). However at 60 months, 2 infrabony defects in the control group had lost all the attachment that had been gained 6 months after therapy and a clinically relevant but statistically in significant mean CAL-V loss of 1.0 +/- 2.1 mm was observed from 6 to 60 months. The case series failed to show statistically significant differences between test and control regarding CAL-V gain 60 months after surgery. Also subtraction analysis failed to reveal statistically significant differences regarding density gain between both groups 6 and 60 months postsurgically (C6: 26.4 +/- 54.2; C60 62.8 +/- 112.7; T6: 68.7 +/- 72.8; T60. 84.1 +/- 83.6).

CONCLUSIONS

CAL-V gain achieved after GTR therapy in infrabony defects using both non-resorbable and bioabsorbable barriers was quite stable after 5 years in 14 of 16 defects.

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

BACKGROUND

This study clinically compares the outcomes obtained from the use of a bioabsorbable barrier device in combination with demineralized freeze-dried bone allograft (DFDBA) to the results obtained from the barrier device used alone in the treatment of human intraosseous defects.

METHODS

The study consisted of 30 patients with one intraosseous periodontal defect each. The trial included defects with loss of attachment of > or = 6 mm, with a radiographically detectable defect of at least 4 mm and with at least 2 remaining osseous walls. After the hygienic phase, at baseline, probing depth (PD), clinical attachment level (CAL), and recession (REC) were measured. During open flap debridement, the defects were randomly assigned to receive either a polylactic acid (PLA) barrier in combination with DFDBA (test) or a PLA barrier alone (control). Additionally, baseline osseous intrasurgical measurements of the periodontal defect were obtained to evaluate the amount of bone regeneration. PD, CAL, and REC were remeasured at 6 and 12 months postsurgery and osseous measurements repeated at 12 months during a re-entry procedure.

RESULTS

Two-sample t-test comparisons of mean PD, CAL, and REC measurements (mm) between test (PLA+DFDBA) and control (PLA alone) groups at baseline, PLA+DFDBA: PD = 7.3, CAL = 8.1, REC = -0.7; PLA-alone: PD = 7.9, CAL = 8.4, REC = -0.5, were not statistically different (P>0.05). The following mean changes (delta) at 6 months for the test and the control groups were: decreased PD = 3.6 and 4.0 mm; gain CAL = 2.7 and 3.1 mm; and increased REC = -0.8 and -0.8 mm, respectively. At 12 months the changes for the test and control groups were: decreased PD = 3.3 and 4.1 mm; gain CAL = 2.3 and 3.2 mm; and increased REC = -0.8 and -1.0 mm, respectively. Two-sample t-test comparisons between PD, CAL, and REC changes yielded no significant differences between treatments (P > 0.05), except for the change in CAL at 12 months in favor of the control group, P = 0.008. Comparisons of osseous measurements resulted in no significant differences between groups at baseline and at 12 months (P > 0.05). The intrabony defect filled on the average 3.72 mm for the test and 4.85 mm for the control group. The experimental defects showed a 4.73 mm defect depth reduction, while the control defects reduced 5.35 mm. Re-entry measurements of osseous crest resorption were 1.1 mm for the test and 0.61 mm for the control.

CONCLUSIONS

In the intraosseous defects treated in this study, the addition of DFDBA to the GTR procedure did not significantly enhance the clinical results obtained with the GTR procedure alone.

Effects of various implant materials on regeneration of calvarial defects in rats

The purpose of the present study was to determine the best implant material, the best conditions to substitute absorbable membrane for non-absorbable membrane, and the factors influencing guided regeneration of critical size defects using experimental rats. An 8-mm circular transosseous calvarial bony defect was made and implant materials, such as demineralized freeze-dried bone (DFDB), absorbable membrane (BioMesh; Samyang Co., Seoul Korea), non-absorbable membrane (Millipore filter; Micro Filtration System, MA, USA) or a combination of these materials, was placed on the defect. As for the results of sequential time-based guided bone regeneration, histological, histochemical, immunohistochemical and histomorphometric aspects were observed, and a statistical comparative analysis was performed, with control group of a soft tissue flap. Bone formation was significantly enhanced when DFDB was retained within the defect with a protective absorbable membrane. Inframembranous DFDB-filling was required to prevent membrane collapse and to preserve spaces for bone regeneration. The absorbable membrane which was recommended to overcome the disadvantages of the non-absorbable membrane should remain intact for more than 5 weeks in order for it to be effective. The macrophages recruited by grafts were involved partly in decreasing bone regeneration via the sequential events of releasing fibronectin, and in chemotactic effect of the fibronectin to fibroblasts and collagen lay-down. Thus, the activity of new bone formation was dependent upon the physical barrier effect of the membrane, such as the preserving ability to secure spaces and the suppression ability of early infiltration of collagen and epithelium, inducible ability of inflammation by the implant material, and potential in guiding bone regeneration of the grafts.

Use of bovine-derived anorganic bone associated with guided tissue regeneration in intrabony defects. Six-month evaluation at re-entry

BACKGROUND

Different filling materials have been associated with guided tissue regeneration (GTR) in order to improve its regenerative potential and predictability. Anorganic bovine bone (ABB) has demonstrated biocompatibility and osteoconductive properties; however, there are limited data regarding its performance in the treatment of intrabony defects. This investigation aimed to evaluate the clinical outcome of the association of anorganic bovine bone with cellulose membranes in intrabony defects after 6 months.

METHODS

Twenty-six paired intrabony defects were selected from 11 non-smoking patients with no relevant medical history. The defects were similar regarding the number of bony walls and defect depth, and presented pocket depths > or = 6 mm. Four weeks after completion of basic therapy, probing depth (PD), clinical attachment level (CAL), and gingival margin position (GP) were recorded (baseline values). The defects were then surgically accessed and debrided, and the intrabony component measured to the nearest millimeter with periodontal probes and customized acrylic stents (distance from the stent to the base of the defect and from the stent to the alveolar crest). Each intrabony defect was randomly assigned to receive the membrane alone (control, C) or the membrane with anorganic bovine bone (test, T). The patients were re-evaluated after 6 months, and re-entry procedures were performed.

RESULTS

Significant (P <0.01) improvement in all variables was observed: mean pocket reduction of 4.61+/-1.60 mm (C) and 4.46+/-1.50 mm (T) and clinical attachment gain of 2.85+/-1.46 mm (C) and 3.15+/-1.40 mm (T); the difference between groups was not significant (P >0.05). Nevertheless, gingival recession in the control group (1.84+/-0.89 mm) was significantly (P <0.05) more pronounced than that observed in the test group (1.30+/-0.48 mm). Bone measurements indicated a significant resolution of the defects (P <0.01). A mean defect resolution of 2.76+/-0.72 mm (C) and 2.69+/-1.03 mm (T) and crestal resorption of 1.07+/-0.64 mm (C) and 1.30+/-0.85 mm (T) were detected (P >0.05). Stepwise multiple regression analysis indicated that for both groups, the baseline depth of the defects and the alveolar crest resorption accounted for 82% of the variability of bone fill observed in the control group (F = 23.65, P <0.001) and 89% in the test group (F = 41.32, P <0.001).

CONCLUSIONS

ABB may be used in conjunction with GTR in the treatment of intrabony defects. Its use, however, did not result in a better outcome than the use of membranes alone. Studies employing more patients would be of interest in order to determine the advantages and indications of the tested approaches on a more predictable basis.

The effect of postsurgical naproxen and a bioabsorbable membrane on osseous healing in intrabony defects

BACKGROUND

Previous reports in the literature have shown that non-steroidal anti-inflammatory drugs (NSAID) may affect osseous tissues by either stimulating or inhibiting bone formation. This effect can be drug specific and different NSAIDs may produce opposite results. There are also reports showing that NSAIDs inhibit bone loss due to inflammatory disease process. The purpose of this randomized, controlled, blinded, clinical investigation was to determine the effect of a one week course of postsurgical naproxen on the osseous healing in intrabony defects.

METHODS

Twenty-four vertical osseous defects in 24 patients were treated with either a bioabsorbable membrane plus twice daily postsurgical naproxen 500 mg for one week (test or GPN group) or with a polylactide bioabsorbable membrane alone (control or GA group). Twelve patients were included in each group. Treatment was performed on either 2- or 3-wall or combination defects. All measurements were taken from a stent by a calibrated, blinded examiner and open measurements were repeated at the 9-month second stage surgery. Power analysis to determine superiority of naproxen treatment showed that a 12 per group sample size would yield 87% power to detect a 2.0 mm difference and 64% power to detect a 1.5 mm difference.

RESULTS

Open defect measurements from baseline to 9 months showed a statistically significant (P < 0.05) mean defect fill of 1.96 +/- 1.27 mm and 2.04 +/- 1.71 for the GPN and GA groups, respectively. This corresponded to a mean defect fill of 42% and a mean defect resolution of approximately 75% for both groups. The differences between GPN and GA groups were not statistically significant (P > 0.05). Defect fill of > or = 50% was seen in 6 defects (50%) in the GPN group and in 5 defects (42%) in the GA group.

CONCLUSIONS

The administration of postsurgical naproxen failed to produce osseous healing that was statistically superior to that obtained with polylactide bioabsorbable membranes alone.

The use of 2 bioabsorbable barrier membranes in the treatment of interproximal intrabony periodontal defects

BACKGROUND

The use of barrier membranes in the treatment of periodontal defects is well documented. There has been an increase in the use of bioabsorbable materials which do not require a second surgical procedure for removal. However, there are little data evaluating the efficacy of bioabsorbable membranes in the treatment of intrabony defects. The purpose of this investigation was to evaluate the regenerative potential of 2 bioabsorbable barrier membranes without the use of grafting materials in the treatment of interdental intrabony defects.

METHODS

Twenty-three 2- or 3-walled intrabony defects were treated in 19 patients with a mean age of 50.4 years. All had completed nonsurgical treatment and a period of supportive periodontal therapy. The sites were randomly chosen to receive a barrier membrane composed of type I bovine collagen (11) or a copolymer of polylactic acid (PGA/PLA;12). A pressure sensitive disc probe was used to evaluate the following criteria at baseline and re-entry: 1) occlusal surface to the apical depth of probe penetration (OS-DP); 2) occlusal surface to the gingival margin (OS-GM); 3) occlusal surface to the alveolar crest (OS-AC); and 4) occlusal surface to the base of the osseous defect (OS-BD). Full thickness mucoperiosteal flaps were reflected to expose the surgical sites. The defects were debrided of the granulomatous tissue, the root surfaces instrumented and conditioned with 4 one-minute applications of 50 mg/ml of tetracycline. The barrier membranes were adapted to cover the defects and the flaps replaced. The postsurgical healing was uneventful and similar in both treatment modalities.

RESULTS

Twenty-three sites were surgically re-entered 6 months from the time of the initial surgery. The deepest probe depth for each site was used for statistical analysis. There was a mean relative attachment gain of 2.58+/-1.90 mm for the collagen, and 2.77+/-2.13 mm for the copolymer. There was a decrease in probing depth of 3.27+/-1.91 mm and 0.69+/-1.35 mm of recession for the collagen. The PGA/PLA copolymer had 3.55+/-2.47 mm reduction in probe depth and 0.78+/-1.14 mm of recession.

CONCLUSIONS

The data indicated the bioabsorbable collagen and copolymer membranes resulted in comparable results. A larger sample size would be necessary to determine if one membrane was superior to the other.

Guided tissue regeneration for the treatment of intraosseous defects using a biabsorbable membrane. A controlled clinical study

The aim of this controlled, clinical study was to evaluate guided tissue regeneration using a bioabsorbable membrane in periodontal intraosseous defects. Forty patients, each contributing one defect > or =4 mm in depth participated. The control group (18 individuals) received conventional flap therapy, while the test group (22 individuals) was treated using the bioabsorbable membrane, Guidor. Clinical assessments were made by one examiner, blinded with respect to treatment group, at baseline, 6 and 12 months following surgery. Baseline probing pocket depths of 7.7+/-1.4 mm in the membrane group and 7.6+/-1.9 mm in the control group were measured. Twelve month results showed a significant clinical attachment level gain in both control (1.1+/-1.8 mm), and membrane group (1.3+/-2.1 mm). Probing pocket depth reduction of 2.6+/-1.9 mm and 2.7+/-1.9 mm was observed in the respective groups. Bone sounding showed a non-significant gain of 0.4+/-1.8 mm and 0.6+/-1.4 mm at membrane and control sites, respectively. Radiographic evaluation confirmed these results. There were no significant differences found between treatment groups for any of the tested variables. Smoking had a negative effect on healing in both groups. In conclusion, clinical and radiographic results indicate that guided tissue regeneration using a bioabsorbable membrane at intraosseous defects did not predictably achieve greater clinical attachment level gain nor bone gain when compared to conventional flap therapy.

Evidence for healing of interproximal intrabony defects after conventional and regenerative therapy: digital radiography and clinical measurements

In 24 patients with advanced periodontitis 38 interproximal intrabony defects were treated by conventional surgery (C; n = 8) or guided tissue regeneration (GTR) using expanded polytetrafluoroethylene (G; n = 17) or Polyglactin 910 barriers (V; n = 13). Presurgically (BL), 6 and 12 months postsurgically clinical parameters (GI, PII, PPD, PAL-V) and 36 standardized radiographs were obtained generating 72 pairs (36 BL/6 months; 36 BL/12 months). Using linear measurements on the radiographs and subtraction analysis, bony fill within the defects was assessed. Intrasurgically the extension of the intrabony defects was measured. Statistically significant (p < 0.05) attachment gain was found after 6 (C: 2.4 +/- 1.6 mm; G: 3.2 +/- 1.6 mm; V: 3.4 +/- 1.5 mm) and 12 months in all groups (C: 2.4 +/- 1.7 mm; G: 3.1 +/- 1.7 mm; V: 4.0 +/- 1.7 mm). Thirty-nine of 72 pairs of radiographs were unsuitable for subtraction analysis. Significant (p < 0.05) bony fill was observed at 6 (C: 0.3 +/- 1.0 mm; G: 0.7 +/- 1.2 mm; V: 0.9 +/- 1.2 mm) and 12 months (C: 0.0 +/- 1.1 mm; G: 1.4 +/- 1.5 mm; V: 1.5 +/- 1.7 mm) only after GTR surgery. GTR therapy yielded significantly more bony fill than conventional surgery 12 months postsurgically (p < 0.1). Bony fill (linear measurement) was influenced by age, smoking, baseline bone loss and PAL-V gain (p < 0.0001). Significantly more radiographs taken with potentially unstable support of the filmholder were not suitable for subtraction analysis than those with stable support (p < 0.05). Bony gain (subtraction analysis) was positively modulated by bony fill (linear measurement) and use of biodegradable barriers (p = 0.002). There is a correlation between PAL-V gain and bony fill (linear measurement). Smoking impairs attachment gain and bony fill. Potentially stable support of the filmholder provided radiographs suitable for subtraction analysis.

Effects of expanded polytetrafluoroethylene and polylactic acid barriers on healthy sites

The configuration of the barrier devices to treat interproximal defects by guided tissue regeneration (GTR) necessitates inclusion of healthy adjacent teeth to secure the barriers in place. The purpose of this study was to evaluate the effects of expanded polytetrafluoroethylene (ePTFE) and polylactic acid (PLA) barrier devices on probing depth (PD), clinical attachment level (CAL), and crestal bone height in healthy sites. The study included 30 patients who were in an earlier study which compared the effects of GTR utilizing an ePTFE or a PLA barrier in intrabony defects. Thirty defects were randomly assigned to receive either a PLA (test) or an ePTFE barrier (control) after open flap debridement. The sites in this investigation included those healthy sites in the immediately adjacent non-affected teeth covered by the barriers. CAL and PD were measured at baseline and 12 months. Intrasurgical crestal bone height was recorded at the time of barrier placement and at a 12-month re-entry. Two-sample t-test comparisons of PD and CAL measurements between barrier device covered sites at baseline (PD: ePTFE, 2.32+/-0.51; PLA, 2.59+/-0.74; CAL: ePTFE, 2.71+/-0.66; PLA, 2.59+/-0.65 mm), and at one year (PD: ePTFE, 2.14+/-0.37; PLA, 2.07+/-0.56; CAL: ePTFE, 3.14+/-1.05; PLA, 2.75+/-0.73 mm) were not statistically different (P > 0.05). Paired t-test was utilized to compare changes in PD, CAL, and crestal bone height from baseline to 12 months. A statistically significant reduction in PD was found in the PLA group (delta = -0.52, P = 0.01) while no significant change was found in the ePTFE group (delta = -0.18, P = 0.18). Change in CAL was statistically significant in the ePTFE group (delta = 0.43, P = 0.02) while no significant change was found in the PLA group (delta = 0.16, P = 0.39). Crestal bone height changes from baseline to 12 months were statistically different for both groups (ePTFE, delta = 0.8 mm, P = 0.001; PLA, delta = 0.6 mm, P = 0.001). These resorptive changes, when compared between treatment groups were not statistically different (P > 0.05). In conclusion, the placement of ePTFE or PLA barriers on healthy sites resulted in probing depth reductions and loss of attachment of 0.5 mm or less. Additionally, both groups exhibited less than 1.0 mm of crestal bone resorption.