Osseous repair in infrabony periodontal defects

Recombinant human fibroblast growth factor and autogenous bone for periodontal regeneration: Alone or in combination? A randomized clinical trial

AIM

To compare the outcomes of therapy using recombinant human fibroblast growth factor (rhFGF)-2 combined with autologous bone grafting (ABG) therapy with those of rhFGF-2 alone and ABG alone in the treatment of periodontal intraosseous defects.

METHODS

Periodontal intraosseous defects were randomized to receive rhFGF-2 therapy + ABG, rhFGF-2 therapy alone, or ABG alone. Periodontal examination and periapical radiography were performed preoperatively and at 3, 6, and 12 months postoperatively.

RESULTS

At the 12 months follow-up, all three groups showed significant improvement in the clinical attachment level (CAL): 5.6 ± 1.6, 5.8 ± 1.7, and 5.2 ± 1.6 mm in the rhFGF-2 + ABG, rhFGF-2 alone, and ABG alone groups, respectively, with no significant inter-group differences (p < .05). rhFGF-2 therapy (alone or in combination) resulted in greater bone defect filling (BDF) (2.3 ± 1.2 mm and 2.6 ± 1.9 mm, respectively) than ABG therapy alone (1.2 ± 1.2 mm). Gingival recession was lesser in the ABG alone (1.2 ± 1.1 mm) and rhFGF-2 + ABG groups (1.4 ± 0.8 mm) than in the rhFGF-2 alone group (2.2 ± 1.2 mm).

CONCLUSION

The results of this study showed that at 12 months postoperatively, all treatments resulted in statistically significant clinical improvements compared to the baseline. From these results, it can be concluded that rhFGF-2 promotes hard tissue regeneration in intraosseous defects.

Recombinant Human Derived Growth and Differentiating Factors in treatment of periodontal intrabony defects: Systematic review and network meta-analysis

The introduction of recombinant human growth and differentiation factors (rhGFs) for intrabony defects regeneration has represented a considerable breakthrough in recent years. However, they have been used in different concentrations, doses and combined with various scaffolds, and there is no evidence on which the most effective formulation for periodontal regeneration is. Therefore, we aimed to evaluate and rank the various formulations of such bioactive agents through network meta-analysis of clinical studies. The protocol registration was done on PROSPERO with registration ID CRD42020213753. To report NMA, we followed PRISMA guidelines and searched PUBMED, Embase, Web of Science and Cochrane Central electronic databases. Studies were screened based on specific inclusion criteria. Primary outcomes extracted from included studies were the most common indexes for periodontal regeneration (PPD, CAL, %bone filling). The NMA analysis included network plots, contribution plots, inconsistency plots (if eligible to form the loop), predictive interval plots, SUCRA rankings and multidimensional scale ranking (MDS) plots. SUCRA would demonstrate the rankings of multiple competing bioactive agents based on their best performance. Twelve clinical studies for qualitative and quantitative analysis were considered. Network meta-analysis found that rhFGF + hydroxyapatite was ranked highest in PPD and CAL outcome. rhPDGF-BB+β-tricalcium phosphate was ranked highest in the percentage of bone filling. In addition, all bioactive agents performed better than control groups without rhGFs. Despite clear benefits deriving from rhGFs for periodontal regeneration, the present results should be interpreted with caution due to several confounding factors affecting the outcome. Nevertheless, further well designed randomized clinical trials will allow establishing guidelines for an appropriate indication of the use of rhGFs.

Periodontal surgery using rhFGF-2 with deproteinized bovine bone mineral or rhFGF-2 alone: 2-year follow-up of a randomized controlled trial

AIM

To compare outcomes of rhFGF-2 + DBBM therapy with rhFGF-2 alone in the treatment of intrabony defects. This study provides 2-year follow-up results from the previous randomized controlled trial.

MATERIALS AND METHODS

Defects were randomly allocated to receive rhFGF-2 + DBBM (test) or rhFGF-2 (control). Treated sites were re-evaluated at 2 years postoperatively, using original clinical and patient-centred measures.

RESULTS

Thirty-eight sites were available for re-evaluation. At 2 years, both groups showed a significant improvement in clinical attachment level (CAL) from baseline. A gain in CAL of 3.4 ± 1.3 mm in the test group and 3.1 ± 1.5 mm in the control group was found. No significant inter-group difference was noted. Both groups showed a progressive increase in radiographic bone fill (RBF). The test treatment yielded greater RBF (56%) compared with the control group (41%). The control treatment performed better in contained defects in terms of CAL and RBF. There was no significant difference in patient-reported outcomes between groups.

CONCLUSIONS

At 2-year follow-up, the test and cotrol treatments were similarly effective in improving CAL, whereas the test treatment achieved a significantly greater RBF. In both treatments, favourable clinical, radiographic, and patient-reported outcomes can be sustained for at least 2 years.

TRIAL REGISTRATION

The University Hospital Medical Information Network-Clinical Trials Registry (UMIN-CTR) 000025257.

Periodontal infrabony defects: Systematic review of healing by defect morphology following regenerative surgery

BACKGROUND

It is thought that infrabony defect morphology affects the outcome of periodontal regenerative surgery. However, this has not been systematically investigated.

AIMS

To investigate how well defect morphology is described in papers reporting regenerative therapy of periodontal infrabony defects and to investigate its effect on clinical and radiographic outcomes.

MATERIALS AND METHODS

A search was conducted in 3 electronic databases for publications reporting clinical and radiographic outcomes of periodontal intra-bony defects after regenerative therapy, divided by defect morphology.

RESULTS

The initial search resulted in 4487 papers, reduced to 143 after first and second screening. Fifteen of these publications were suitable for a fixed-effects meta-analysis. Initial defect depth was found to influence radiographic bone gain 12 months post-surgery, while narrower angles and increased number of walls influenced both radiographic bone gain and clinical attachment level (CAL) gain at 12 months. These associations seemed to occur irrespective of biomaterials used. Risk of bias ranged from low to high.

CONCLUSION

Deeper defects with narrower angles and increased number of walls exhibit improved CAL and radiographic bone gain at 12 months post-regenerative surgery. More data are needed about other aspects of defect morphology such as extension to buccal/lingual surfaces.

Impact of bone defect morphology on the outcome of reconstructive treatment of peri-implantitis

OBJECTIVES

To assess if (I) the alveolar bone defect configuration at dental implants diagnosed with peri-implantitis is related to clinical parameters at the time of surgical intervention and if (II) the outcome of surgical intervention of peri-implantitis is dependent on defect configuration at the time of treatment.

MATERIALS AND METHODS

In a prospective study, 45 individuals and 74 dental implants with ≥ 2 bone wall defects were treated with either an autogenous bone transplant or an exogenous bone augmentation material. Defect fill was assessed at 1 year.

RESULTS

At baseline, no significant study group differences were identified. Most study implants (70.7%, n = 53) had been placed in the maxilla. Few implants were placed in molar regions. The mesial and distal crestal width at surgery was greater at 4-wall defects than at 2-wall defects (p = 0.001). Probing depths were also greater at 4-wall defects than at 2-wall defects (p = 0.01). Defect fill was correlated to initial defect depth (p < 0.001). Defect fill at 4-wall defects was significant (p < 0.05).

CONCLUSIONS

(I) The buccal-lingual width of the alveolar bone crest was explanatory to defect configuration, (II) 4-wall defects demonstrated more defect fill, and (III) deeper defects resulted in more defect fill.

Optimal management of intrabony defects: current insights

Periodontitis is the most common condition, which causes bony defects. Intrabony defects thought not as common as the horizontal bone loss pose a risk of disease progression and thus should be managed optimally; however, it does not mean all the intrabony defects can be treated and all the mobile teeth saved! But, with the advent of new biomaterials prognosis of teeth can be improved. The objective of this article is to discuss old and new concepts toward the optimal management of intrabony defects.

Wound models for periodontal and bone regeneration: the role of biologic research

The ultimate goals of periodontal therapy remain the complete regeneration of those periodontal tissues lost to the destructive inflammatory-immune response, or to trauma, with tissues that possess the same structure and function, and the re-establishment of a sustainable health-promoting biofilm from one characterized by dysbiosis. This volume of Periodontology 2000 discusses the multiple facets of a transition from therapeutic empiricism during the late 1960s, toward regenerative therapies, which is founded on a clearer understanding of the biophysiology of normal structure and function. This introductory article provides an overview on the requirements of appropriate in vitro laboratory models (e.g. cell culture), of preclinical (i.e. animal) models and of human studies for periodontal wound and bone repair. Laboratory studies may provide valuable fundamental insights into basic mechanisms involved in wound repair and regeneration but also suffer from a unidimensional and simplistic approach that does not account for the complexities of the in vivo situation, in which multiple cell types and interactions all contribute to definitive outcomes. Therefore, such laboratory studies require validatory research, employing preclinical models specifically designed to demonstrate proof-of-concept efficacy, preliminary safety and adaptation to human disease scenarios. Small animal models provide the most economic and logistically feasible preliminary approaches but the outcomes do not necessarily translate to larger animal or human models. The advantages and limitations of all periodontal-regeneration models need to be carefully considered when planning investigations to ensure that the optimal design is adopted to answer the specific research question posed. Future challenges lie in the areas of stem cell research, scaffold designs, cell delivery and choice of growth factors, along with research to ensure appropriate gingival coverage in order to prevent gingival recession during the healing phase.

A systematic review of the use of growth factors in human periodontal regeneration

BACKGROUND

There is a large body of evidence using cells and animal models demonstrating the effectiveness of growth factors in periodontal regeneration. However, there appears to be minimal literature comparing the efficacy of growth factors in human periodontal regeneration compared to other techniques and procedures. Therefore, the aim of this study is to perform a systematic review of human studies using growth factors for periodontal regeneration and to compare the efficacy of these growth factors to other accepted techniques for periodontal regeneration.

METHODS

An electronic and manual search based on agreed search phrases between the primary investigator and a secondary investigator was performed to identify the use of growth factors in periodontics for the literature review. The articles that were identified by this systematic review were analyzed in detail, which included the study of their inclusion and exclusion criteria, outcome measures determination and analysis, risk of bias, adverse events, and conclusions or inference of the efficacy of growth factors to the general population.

RESULTS

Five papers fulfilled the inclusion criteria. Two papers were identified that had sufficiently similar study design that a meta-analysis of their outcomes was possible. Most of the reported outcomes from the selected papers were descriptive. The articles demonstrated periodontal regeneration at least comparable to their respective positive controls, with only a couple of articles demonstrating significantly greater outcomes compared to their respective positive controls. Histologic evidence demonstrated greater periodontal regeneration when using growth factors compared to other regenerative techniques and an increased healing and bone maturation rate compared to other regenerative and bone augmentation techniques in these human studies.

CONCLUSIONS

Within the limits of this systematic review, the use of recombinant human platelet-derived growth factor-BB (rhPDGF-BB) led to greater clinical attachment level gain of ≈1 mm compared to an osteoconductive control, β-tricalcium phosphate (β-TCP). The use of rhPDGF-BB led to greater percentage bone fill of ≈40% compared to the osseoconductive control, β-TCP. Last, the use of rhPDGF-BB led to an increased rate of bone growth of ≈2 mm compared to the osseoconductive control, β-TCP.

An evaluation of platelet-rich plasma without thrombin activation with or without anorganic bone mineral in the treatment of human periodontal intrabony defects

The efficacy of platelet-rich plasma (PRP) in periodontal regeneration is not well understood and the definite clinical viability of blood derived platelets lacks clarity. Also, the use of thrombin for platelet activation is disputed. Hence, the purpose of this study was to evaluate the efficacy of blood derived platelets without thrombin activation, alone or in combination with bovine anorganic bone mineral (ABM), in the treatment of human periodontal intrabony defects. PRP was prepared using a simple tabletop centrifuge and activated using calcium chloride without the addition of thrombin. This PRP was used alone (in Group A) and in combination with bovine ABM (in Group B) in the treatment of human periodontal angular defects. Both the control and the test groups showed definite improvement in clinical parameters. On comparison, however, there was a statistically significant improvement in the probing pocket depths and relative attachment level in Group B over Group A at 3 and 6 months intervals, whereas at the end of 9 months this difference was not statistically significant. There was no statistically significant difference between the groups with respect to the relative defect depth. Within the limitations of this study and the type of PRP used, i.e. without thrombin mediated activation, it can be concluded that both PRP and PRP combined with bovine ABM results in significant clinical improvement. Albeit statistically insignificant, there is a preponderance of better clinical results with the addition of ABM to PRP. Further studies need to be carried out on a larger sample size to confirm the results of the present study.

Stability of treated angular and horizontal bony defects: a retrospective radiographic evaluation in a private periodontal practice

BACKGROUND

This retrospective radiographic evaluation provided a comparative assessment of long-term alterations of alveolar bone levels at sites with angular and horizontal bony defects that underwent open-flap debridement and did not undergo resective or regenerative periodontal therapy.

METHODS

The investigation included 50 patients (27 met inclusion criteria) who had periodontal surgery and periodontal maintenance every 3 to 6 months and who presented with sites demonstrating radiographic angular defects and sites on adjacent or contralateral teeth that demonstrated horizontal bone loss. Subsequent to surgical therapy, alterations in bone levels at the alveolar crest of horizontal defects and at the base of angular defects were evaluated by comparing radiographs from the initial examination to those obtained after a period of periodontal maintenance (6 to 16 years; mean: 8.83 years).

RESULTS

After periodontal therapy, sites with angular and horizontal alveolar bone loss had additional bone loss of 5.56% and 3.88%, respectively.

CONCLUSION

Based on a defining criterion of 10%, the angular and horizontal sites were clinically equivalent with respect to the magnitude of osseous resorption that occurred after periodontal surgery and maintenance.

Bone replacement grafts for the treatment of periodontal intrabony defects

Bone replacement grafts, including autogenous grafts from intraoral donor sites, allografts, xenografts, and alloplastic bone substitutes, are the most widely used treatment modalities for the regeneration of periodontal osseous defects. Studies suggest a favorable clinical outcome with the use of these materials in terms of improvements in periodontal probing depths, probing attachment gains, and bone fill. In terms of bone fill, most studies report more than 50% resolution of intrabony defects when treated with bone replacement grafts. However, histologic evidence of periodontal regeneration, including new bone, periodontal ligament, and cementum, has been reported only for autogenous bone grafts and demineralized freeze-dried bone allografts.

Treatment of Intrabony Defects With an Enamel Matrix Protein Derivative or Bioabsorbable Membrane: An 8-Year Follow-Up Split-Mouth Study

BACKGROUND

Treatments with either an enamel matrix protein derivative (EMD) or guided tissue regeneration (GTR) have been shown to promote periodontal regeneration. However, until recently, only limited data have been available on the long-term clinical results following these regenerative techniques. Therefore, the aim of this study was to present the 8-year results of a prospective, controlled, split-mouth clinical study evaluating the treatment of intrabony defects with EMD or GTR.

METHODS

Ten patients, each of whom displayed one pair of intrabony defects located contralaterally in the same jaw, were randomly treated with EMD or with GTR by means of bioabsorbable membranes. The following clinical parameters were evaluated at baseline and at 1 and 8 years after treatment: plaque index (PI), gingival index (GI), bleeding on probing (BOP), probing depth (PD), gingival recession (GR), and clinical attachment level (CAL). The primary outcome variable was CAL. No statistically significant differences between the groups were found at baseline.

RESULTS

The sites treated with EMD demonstrated a mean CAL change from 9.5 +/- 1.2 mm to 6.3 +/- 1.3 mm (P <0.001) and 6.7 +/- 1.6 mm (P <0.001) at 1 and 8 years, respectively. No statistically significant differences were found between the 1- and 8-year results. Sites treated with GTR showed a mean CAL change from 9.7 +/- 1.3 mm to 6.7 +/- 0.9 mm (P <0.001) at 1 year and 6.8 +/- 1.2 mm (P <0.001) at 8 years. The CAL change between 1 and 8 years did not present statistically significant differences. Between the treatment groups, no statistically significant differences in any of the investigated parameters were observed at 1 and at 8 years. However, the study does not have the statistical power to rule out the possibility of a difference between the two groups.

CONCLUSIONS

Within their limits, the present results indicate the following: 1) the clinical improvements obtained following treatment with EMD or GTR can be maintained over a period of 8 years; and 2) further studies of much higher power need to be performed to support equivalence.

EDTA Gel Root Conditioning: Lack of Effect on Clinical and Radiographic Outcomes of Intrabony Defect Treatment With Enamel Matrix Derivative

BACKGROUND

The adjunctive use of enamel matrix derivative (EMD) in the surgical therapy of intrabony defects results in improved outcomes compared to surgical debridement alone. However, the role of EDTA root conditioning in EMD therapy has not been investigated. The purpose of this study was to compare the 12-month outcomes of EMD application with and without EDTA root conditioning in intrabony defect surgical therapy.

METHODS

Twenty-eight chronic periodontitis patients, each contributing a 2- or 3-wall intrabony defect (> or = 4 mm deep and > or = 2 mm wide), participated. Patients consecutively received surgical treatment with either EMD alone (first 13 patients) or EMD + EDTA (subsequent 15 patients). Probing depth (PD), clinical attachment level (CAL), and gingival margin position, i.e., recession (REC) were the clinical parameters recorded. Recorded radiographic parameters were the distances from 1) cemento-enamel junction to bone crest (CEJ to BC), 2) CEJ to base of the defect (CEJ to BD), and 3) BC to BD.

RESULTS

Intragroup analysis showed that both EMD alone and EMD + EDTA led to significant PD reduction, CAL gain, and REC increase 1 year postoperatively. Both groups had >60% mean radiographic defect resolution (change in BC to BD). None of the recorded parameters were significantly different between the two groups, either at baseline or postoperatively.

CONCLUSIONS

These results suggest that clinical and radiographic outcomes of intrabony defect EMD therapy do not depend on the use of EDTA gel root conditioning. The potential contribution of EDTA gel root conditioning to the histological outcomes reported with EMD therapy remains to be determined.

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.

Periodontal regeneration techniques for treatment of periodontal diseases

The ultimate goal of periodontal therapy is the regeneration of structures lost to disease. Conventional surgical approaches such as open-flap debridement offer only limited regeneration potential.Currently, surgical procedures for predictable regeneration of periodontal tissues are being developed, analyzed, and employed in clinical practice. This article addresses current trends in periodontal regeneration. Various materials/agents such as bone replacement grafts, barrier membranes, and biologic modifiers currently used for the regeneration of periodontal infrabony and furcation defects are discussed.

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.

Geometric alignment and chromatic calibration of serial radiographic images

OBJECTIVE

To develop software for automated registration and intensity calibration of serial dental radiographs for the analysis of longitudinal changes in bone density.

METHODS

Serial dental radiographs were acquired using a positioning device designed to minimize projection divergence. Each radiograph included an image of a standardized aluminium wedge. The radiographs were scanned on a flatbed scanner (AGFA Duo Scan) with a spatial resolution of 300 dpi, and pixel intensity coded in 16-bit grey scale. The intensity was calibrated using serial images of selected areas with defined thickness of the aluminium wedge. A robust B-splines multiresolution registration algorithm was implemented to overcome the acquisition misalignment. Radiographs, taken before and after periodontal therapy, were subtracted to assess bone density evolution.

RESULTS

The intensity calibration decreased the maximum intensity variations between serial radiographs from 30+/-17% to 1+/-1% (mean+/-standard deviation), and improved the visual comparison between the radiographs. The registration stage allowed correcting the misalignment of the radiographs on the scanner screen and superimposing the radiography contents. The observed residual motion was about 0.02+/-0.01 mm.

CONCLUSION

Very user-friendly software was developed. The manipulator needs to scan the radiographs only one time. The software performs all subsequent processing steps.

Bone Apposition in Surgical Bony Defects Following Orthodontic Movement: A Comparative Histomorphometric Study Between Root- and Periodontal Ligament-Damaged and Periodontally Intact Rat Molars

BACKGROUND

The influence of orthodontic tooth movement with diminished periodontal support is unclear. The aim of the present study was to evaluate bone healing in surgical defects following orthodontic tooth movement with and without periodontal ligament (PDL) and root surface damage.

METHODS

The study comprised 33 adult male Wistar rats, divided into two groups: group 1 (n = 14) with bony defect and no root damage and group 2 (n = 19) with periodontal bony defect including root/PDL damage on the mesial root of the maxillary first molar. One week after a surgical defect was created, orthodontic protraction of the right maxillary first molar was initiated in both groups. After 2 weeks of protraction, retention of 1 week was established; at the end of this period block sections were made. Histomorphometric analysis through light microscopy of decalcified tissue was performed. Results were statistically analyzed using independent samples t test and analysis of variance (ANOVA) with repeated measures.

RESULTS

Differences between groups in total area of bone defect and bone apposition were not statistically significant. Bone apposition calculated as percentage of the bone defect was significantly (t-test) greater (P = 0.002) in group 2 (46.21%) than in group 1 (24.95%). Within each group, area of bone apposition was significantly (ANOVA) greater in the distal than in the mesial quadrants of the bony defect (P = 0.006) and in the apical than the occlusal ones (P = 0.021).

CONCLUSION

Following orthodontic tooth movement, periodontal bony defects showed enhanced bony healing compared with alveolar bone defects with no direct association with the periodontal attachment apparatus.

Periodontal Repair in Surgically Created Intrabony Defects in Dogs: Influence of the Number of Bone Walls on Healing Response

BACKGROUND

The objective of this study was to histologically evaluate periodontal healing following flap surgery in intrabony periodontal defects to determine the influence of the number of bone walls on periodontal regeneration.

METHODS

One-, 2-, and 3-wall intrabony periodontal defects were surgically produced at the proximal aspect of mandibular premolars in either right or left jaw quadrants in six beagle dogs. Mucoperiosteal flaps were positioned and sutured to their presurgery position following defect preparation. The animals were euthanized at 8 weeks post-surgery, and block sections of the defect sites were collected for histologic and histometric analysis.

RESULTS

Bone and cementum regeneration was positively correlated to the number of bone walls limiting the intrabony periodontal defects. The junctional epithelium averaged (+/- SD) 1.5 +/- 0.2, 1.2 +/- 0.3, and 0.9 +/- 0.2 mm for the 1-, 2-, and 3-wall defects, respectively, with the 3-wall defects being significantly different from the 1-wall defects (P <0.05). Cementum regeneration averaged 1.2 +/- 0.6, 2.0 +/- 0.6, and 2.8 +/- 0.5 mm for the 1-, 2-, and 3-wall defects, respectively; all groups were significantly different from each other (P <0.05). Bone regeneration averaged 1.5 +/- 0.5, 1.7 +/- 0.6, and 2.3 +/- 0.5 mm for the 1-, 2-, and 3-wall defects, respectively, with the 3-wall defects being significantly different from the 1-wall defects (P <0.05).

CONCLUSIONS

The results suggest that the number of bone walls is a critical factor determining treatment outcomes in intrabony periodontal defects. One- and 3-wall intrabony defects appear to be reproducible models to evaluate candidate technologies for periodontal regeneration.

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.

Clinical and radiographic evaluation of periodontal intrabony defects treated with guided tissue regeneration. A pilot study

BACKGROUND

The aim of this clinical and radiographic study was to evaluate the effect of guided tissue regeneration using a bioabsorbable barrier in the treatment of intrabony defects in humans.

METHODS

Intrabony osseous defects (2 or 3 walls) around mandibular canines and premolars were treated in 10 systemically healthy patients with ages ranging from 35 to 56 years. Prior to the surgical phase, patients were enrolled in a strict maintenance program including oral hygiene instructions and scaling and root planing (presurgical Pi and GI < 10%). Patients were seen for professional prophylaxis during the duration of the study. Clinical measurements were performed with an electronic probe at baseline and at reentry 8 months following surgical therapy. Measurements included clinical attachment levels (CAL), gingival margin levels (GML), probing depths (PD), bone defect levels (BDL), and alveolar crest level (ACL). A split mouth design was used. Quadrants were randomly assigned for treatment by GTR (experimental) or open flap debridement alone (control). Standardized radiographs were taken at baseline and at reentry. Digital images were analyzed by subtraction to assess changes in area (A) and optical density (OD). Data were evaluated using paired t test.

RESULTS

Statistically significant differences were found in both groups when comparing baseline and post-treatment values for CAL, GML, PD, and BDL (P < 0.0 1). Greater reductions in BDL and gain in A and OD were observed in the GTR group when compared to control (P < 0.01). Both therapies were effective in improving the clinical parameters assessed.

CONCLUSION

Clinical and radiographic findings from this study demonstrated more bone fill in sites treated with GTR.

Combined periodontal regenerative technique in human intrabony defects by collagen membranes and anorganic bovine bone. A controlled clinical study

BACKGROUND

Combined periodontal regenerative technique (CPRT) is a surgical procedure that combines the use of barrier membranes with a filling material in the treatment of periodontal defects. The effectiveness of CPRT has been evaluated in many studies in comparison to GTR with membranes alone, but conflicting results have been obtained by different clinicians, particularly in the treatment of intrabony defects. The aim of the present study was to compare CPRT to GTR with collagen membranes in the treatment of human intrabony defects characterized by a relevant 1-wall component.

METHODS

Thirty-four (34) healthy, non-smoking patients affected by moderate to severe chronic periodontitis participated in this study. Each patient had good oral hygiene and at least 1 radiographically detectable intrabony defect > or = 4 mm, with a 1-wall component of at least 50% of the defect, involving 2 tooth surfaces or more with a probing depth (PD) > or = 6 mm. Seventeen (17) subjects were randomly assigned to the test group and underwent CPRT by anorganic bovine bone and a collagen membrane, and 17 randomly assigned to the control group who received GTR with a collagen membrane alone. Pre- and post-therapy clinical parameters (probing depth [PD]; clinical attachment level [CAL]; gingival recession [GR]) and intrasurgical parameters (depth of intraosseous component [IOC]; level of the alveolar crest [ACL]) were compared between test and control groups 1 year after treatment. Vertical bone gain (VBG) from the base of the defect to the cemento-enamel junction was also evaluated in both groups.

RESULTS

At the 1-year examination, clinical and intrasurgical parameters showed statistically significant changes within each experimental group from baseline. A statistically greater CAL gain was reported in the test group (P<0.05), whereas the control group exhibited more GR and alveolar crest resorption at a statistically significant level (P<0.01). VBG was significantly greater (P<0.01) at test sites (5.23 +/- 1.30 mm) compared to controls (3.82 +/- 1.28 mm).

CONCLUSIONS

The results suggest that the use of CPRT may be preferred when bioabsorbable membranes are used to treat intrabony defects characterized by unfavorable architecture.

Treatment of intrabony defects with enamel matrix proteins and guided tissue regeneration

BACKGROUND

Utilisation of enamel matrix proteins (EMD) and application of the guided tissue regeneration principle (GTR) are treatment modalities which both have been shown to result in periodontal regeneration. However, it is yet unknown whether the combination of EMD and GTR may additionally favor the regeneration process.

AIM

The aim of the present controlled study was to evaluate clinically the treatment effect of EMD, GTR, combination of EMD and GTR, and flap surgery (control) on intrabony defects.

MATERIAL AND METHODS

56 patients each of whom displaying one intrabony defect of a depth of at least 6 mm were randomly treated with one of the treatment modalities. Prior to surgery and at one year after, the following parameters were evaluated by a blinded examiner: Plaque index (PlI), gingival index (GI), bleeding on probing (BOP), probing pocket depth (PPD), gingival recession (GR) and clinical attachment level (CAL). No statistical significant differences between the four groups were observed at baseline for any of the investigated parameters.

RESULTS

At 1 year after therapy, the sites treated with EMD demonstrated a mean PPD reduction of 4.1 +/- 1.7 mm and a mean CAL gain of 3.4 +/- 1.5 mm (p<0.001). The sites treated with GTR showed a mean PPD reduction of 4.2 +/- 1.9 mm and a mean CAL gain of 3.1 +/- 1.5 mm (p<0.001). The sites treated with the combined treatment showed a mean PPD reduction of 4.3 +/- 1.4 mm and a mean CAL gain of 3.4 +/- 1.1 mm (p<0.001). In the control group, the mean PPD reduction was 3.7 +/- 1.4 mm (p<0.001) and the mean CAL gain measured 1.7 +/- 1.5 mm (p<0.01). All 4 treatments led to statistically significant PPD reduction and CAL gain. All three regenerative treatments led to higher CAL gain than the control treatment (p<0.05). No statistical significant differences in PPD reduction and CAL gain were observed between the three regenerative treatments.

CONCLUSION

It may be concluded that (a) all 3 regenerative treatment modalities may lead to higher CAL gain than the control one, and (b) the combined treatment does not seem to improve the outcome of the regenerative procedure.

Treatment of intrabony defects with enamel matrix proteins or bioabsorbable membranes. A 4-year follow-up split-mouth study

BACKGROUND

Treatment with enamel matrix proteins (EMD) and guided tissue regeneration (GTR) with bioabsorbable membranes has been shown to promote periodontal regeneration; however, until now, there were only limited data on the long-term clinical results following these regenerative techniques. Therefore, the aim of the present study was to present the 4-year results following treatment of intrabony defects with EMD or guided tissue regeneration (GTR).

METHODS

Twelve patients, each displaying one pair of intrabony defects located contralaterally in the same jaw, were randomly treated with EMD or with GTR by means of bioabsorbable membranes. The following clinical parameters were evaluated at baseline, at 1 year, and at 4 years after treatment: plaque index (P1), gingival index (G1), bleeding on probing (BOP), probing depth (PD), gingival recession (GR), and clinical attachment level (CAL). The primary outcome variable was CAL. No statistically significant differences between the groups were found at baseline. Power analysis to determine superiority of EMD treatment showed that the available sample size would yield 70% power to detect a 1 mm difference.

RESULTS

The sites treated with EMD demonstrated mean CAL change from 9.8 +/- 2.0 mm to 6.4 +/- 1.6 mm (P<0.001) and to 6.8 +/- 1.8 mm (P<0.001) at 1 and 4 years, respectively. No statistically significant differences were found between the CAL mean at 1 and 4 years postoperatively. The sites treated with GTR showed a mean CAL change from 9.8 +/- 2.3 mm to 6.6 +/- 1.7 mm (P<0.001) at 1 year and to 6.9 +/- 1.8 mm (P<0.001) at 4 years. The CAL change between I and 4 years did not present statistically significant differences. No statistically significant differences in any of the investigated parameters were observed at 1 and 4 years between the treatment groups.

CONCLUSIONS

It was concluded that the CAL gain obtained following treatment with EMD or GTR can be maintained over a 4-year period.

The simplified papilla preservation flap in the regenerative treatment of deep intrabony defects: clinical outcomes and postoperative morbidity

BACKGROUND

The aims of the present multi-center, randomized, controlled clinical trial were: 1) to compare the efficacy of the simplified papilla preservation flap with and without a barrier membrane in deep intrabony defects; 2) to evaluate the postoperative morbidity and surgical complications; and 3) to preliminarily test the impact of baseline tooth mobility on clinical outcomes.

METHODS

This parallel group, randomized, multi-center, controlled clinical trial involved 112 patients in 8 periodontal practices in 4 countries. A deep intrabony defect in each patient was accessed with the simplified papilla preservation flap. In the test defects, a bioabsorbable membrane was positioned. Patients' experiences with the surgical procedure and postoperative period were evaluated with a questionnaire. Clinical outcomes included clinical attachment level (CAL) and probing depth (PD) changes.

RESULTS

Complete observations were available for 55 test and 54 control defects. CAL gains at 1 year were 3.5 +/- 2.1 mm in the guided tissue regeneration (GTR) group and 2.6 +/- 1.8 mm in the control group (P = 0.0117). CAL gains > or = 4 mm were observed in 50.9% of GTR sites and 33.3% of control sites. A significant center effect of 2.1 mm was observed (P= 0.01). Initial PD (P= 0.01) and baseline tooth mobility (P= 0.036) were significant covariates. During the procedure, 30.4% of test and 28.6% of controls reported feeling moderate pain, and subjects estimated the hardship of the procedure at 24 +/- 25 visual analog scale (VAS) units in the test group, and at 22 +/- 23 VAS in controls. In terms of the investigated outcomes, differences between test and control groups were not statistically significant. Among the postoperative complications, edema was most prevalent at week 1, and more frequently associated with the test treatment (P= 0.01). In the test group, 53.6% of membranes were exposed at week 3.

CONCLUSIONS

The present study further supports the added benefits of guided tissue regeneration with respect to access flap alone in the treatment of deep intrabony defects, as well as the general efficacy of GTR in different clinical settings. Furthermore, our study indicates a possible influence of baseline tooth mobility on clinical outcomes.

Orthodontic tooth movement enhances bone healing of surgical bony defects in rats

BACKGROUND

The question of whether the repair of an alveolar bony defect can be enhanced by orthodontic tooth movement was addressed.

METHODS

Alveolar bone defects were created in 52 Wistar male rats anterior to both maxillary first molars. After 1 week of healing, orthodontic protraction was applied for 2 weeks on the right side, resulting in mesial tipping and displacement movement. Subsequently, a retention appliance was inserted for 1 week. The left side served as the untreated (control) group. Vital bone staining (procion brilliant red H-8) was administered before and after orthodontic traction. Histomorphometric analysis was performed on 62 hemimaxillae using UV confocal microscopy and an imaging program. The total area of the bony defect was divided into 4 equal quadrants, and the area of bony apposition in each quadrant was measured.

RESULTS

The total area of bony apposition was 6.5-fold larger in the treated (26.41 x 10(4) +/- 28.92 x 10(4) microm2) than in the control group (4.07 x 10(4) +/- 2.82 x 10(4) microm2), approaching statistical significance (P = 0.065). The treated occlusal quadrants demonstrated highly significant (P= 0.010), greater bone apposition compared to the control group (13.8-fold) and to the treated apical quadrants (P= 0.04, 5-fold).

CONCLUSIONS

This study confirms that orthodontic tooth movement is a stimulating factor of bone apposition. A conversion in the repair pattern of the bony defect from apicoocclusal in the control group (no tooth movement) to occlusoapical in the treated group (with tooth movement) further supports the linkage between tooth movement and enhanced bone deposition. Clinical implication suggests incorporation of orthodontic tooth movement in regenerative therapy.

A comparative study on the use of Bio-Oss and enamel matrix derivative (Emdogain) in the treatment of periodontal bone defects

The aim of the study was to evaluate the clinical and radiographic outcome following two different techniques of periodontal bone defects treatment. The study included 24 generally healthy subjects with advanced periodontitis. The patients were divided into two equal groups, according to the method applied. In the first group, a bovine-derived hydroxyapatite xenograft (Bio-Oss) combined with a resorbable collagen membrane (Bio-Gide) was used. The other group was treated with enamel matrix derivative (Emdogain). Clinical and radiographic examinations were performed prior to and 1 yr after surgery. The following parameters were evaluated: plaque index, gingival index, probing pocket depth, clinical attachment level, gingival recession, radiographic defect depth, and defect width. All clinical and radiographic parameters (except plaque index and gingival recession) were significantly reduced after treatment in both groups. No differences were revealed between the two groups of patients in examined parameters after treatment. The results demonstrated that the treatment of periodontal bone defects with both techniques leads to similar and significant improvements in clinical and radiographic parameters.

Bioactive glass granules for regeneration of human periodontal defects

PURPOSE

A comparative study which evaluated the effectiveness of bioactive glass granules of uniform size (300-335 microns) for the regenerative treatment of interproximal intrabony periodontal defects was conducted.

MATERIALS AND METHODS

Twelve pairs of advanced periodontal lesions in 12 patients (6 males and 6 females) were treated in a split-mouth design with open flap débridement in the control sites and open flap débridement with bioactive glass particles placed in the test sites.

RESULTS

At 6 months post-treatment, both treatment modalities demonstrated a gain in clinical attachment level (CAL), with the test sites having a significantly (p < .01) greater gain in CAL than the control sites. Reentry procedures were performed to assess the amount of hard tissue fill. The test sites demonstrated significantly (p < .001) more gain in hard tissue fill than the controls.

The effect of postsurgical antibiotics on the healing of intrabony defects following treatment with enamel matrix proteins

BACKGROUND

Regenerative treatment with enamel matrix proteins has been shown to promote healing in intrabony defects. However, up to now various postoperative antibiotic regimens have been used in combination with enamel matrix proteins and therefore it cannot be excluded that the results may also be attributable to the effect of the antibiotic treatment. The aim of this randomized, controlled, blinded, clinical investigation was to determine the effect of postsurgical administration of antibiotics on the healing of intrabony periodontal defects treated with enamel matrix proteins.

METHODS

Thirty-four patients each of whom exhibited one deep intrabony defect were randomly treated with either enamel matrix proteins plus antibiotics (test: EMD + AB) or with enamel matrix proteins alone (control: EMD). The antibiotic regimen consisted of a combination of 3 x 375 mg amoxicillin and 3 x 250 mg metronidazole daily for 7 days. The following parameters were recorded at baseline and at 1 year by the same calibrated and blinded investigator: plaque index (PI), gingival index (GI), bleeding on probing (BOP), probing depth (PD), gingival recession (GR), and clinical attachment level (CAL). Power analysis to determine superiority of antibiotic treatment showed that the available sample size would yield 85% power to detect a 1 mm difference.

RESULTS

No statistically significant differences in any of the investigated parameters between the 2 groups were observed at baseline. No serious adverse events such as allergic reactions or abscesses after any of the treatments were observed during the entire study period. The results have shown that in the EMD + AB group the PD decreased from 9.1 +/- 1.5 mm to 4.5 +/- 1.1 mm (P<0.0001) and the CAL changed from 11.0 +/- 1.6 mm to 7.5 +/- 1.4 mm (P<0.0001). In the EMD group the PD decreased from 9.0 +/- 1.7 mm to 4.3 +/- 1.7 mm (P <0.0001) and the CAL changed from 10.6 +/- 1.6 mm to 7.3 +/- 1.5 mm (P <0.0001). There were no significant differences in any of the investigated parameters between the 2 groups.

CONCLUSIONS

It can be concluded that the systemic administration of amoxicillin and metronidazole adjacent to the use of EMD for the surgical treatment of intrabony periodontal defects does not produce statistically superior PD reduction and CAL gain when compared to treatment with EMD alone. Hence, the present results do not support the routine administration of amoxicillin and metronidazole following regenerative treatment with EMD.

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.

Comparison of enamel matrix proteins and bioabsorbable membranes in the treatment of intrabony periodontal defects. A split-mouth study

BACKGROUND

Enamel matrix proteins (EMP) have recently been introduced as a new modality for regenerative periodontal treatment. However, limited information is available concerning the comparison of the treatment of intrabony periodontal defects with enamel matrix proteins and other regenerative treatment alternatives.

METHODS

The aim of the present controlled clinical trial was to compare the treatment of deep intrabony periodontal defects with EMP to that with guided tissue regeneration (GTR) with bioabsorbable membranes. Sixteen patients, each of whom displayed one pair of intrabony defects located contralaterally in the same jaw, were randomly treated with EMP or with a bioabsorbable membrane. Prior to surgery and 8 months later the following parameters were evaluated by a blinded examiner: Plaque index (PI), gingival index (GI), bleeding on probing (BOP), probing depth (PD), gingival recession (GR), and clinical attachment level (CAL). Antibiotics (amoxicillin and metronidazole) were given during the first 10 days after surgery. No statistical significant differences in any of the investigated parameters between the 2 groups were observed at baseline.

RESULTS

No serious adverse events (e.g., allergic reactions or abscesses) after any of the treatments were noted during the entire observation period. Membrane exposure occurred in 7 out of the 16 GTR treated sites. Clinical examination was performed again 8 months postoperatively. Sites treated with EMP demonstrated a reduction of PD from 8.1+/-1.7 mm to 4.3+/-1.2 mm (P <0.001) and a change in CAL from 10.3+/-1.8 mm to 7.2+/-1.2 mm (P <0.001). The sites treated with GTR showed a reduction of PD from 8.3+/-1.7 mm to 4.3+/-0.7 mm (P <0.001) and a change of CAL from 10.1+/-1.9 mm to 7.1+/-1.7 mm (P <0.001). Both treatment procedures led to significant improvements of PD and CAL. However, no statistically significant differences in any of the investigated parameters were observed between the test and control group.

CONCLUSIONS

It may be concluded that both therapies led to shortterm improvements of the investigated clinical parameters. Further studies of much higher power are needed to support equivalence.

Expanded polytetrafluoroethylene and dental rubber dam barrier membranes in the treatment of periodontal intrabony defects. A comparative clinical trial

As observed in previous case reports, dental rubber dam (DRD) can be utilized as a barrier membrane in the guided tissue regeneration (GTR) technique for the treatment of periodontal intrabony defects. The purpose of the present study was (1) to confirm the validity of DRD as a suitable material in regenerative procedures and (2) to compare, in a split-mouth clinical trial, the effectiveness of DRD-made membranes in the treatment of periodontal intrabony defects versus that of expanded polytetrafluoroethylene (e-PTFE) barriers. 22 systemically healthy non-smoker adult periodontitis patients (7 male, 15 female) aged between 35 to 58 years were selected for the study. In each patient, a couple of 2-3 wall intrabony defects, located in different quadrants, were treated by a GTR technique using DRD (test sites) and e-PTFE (control sites), respectively. Performing a strict control of the oral hygiene level and of the marginal gingival health during the whole period of study, clinical (pocket probing depth, PPD; probing attachment level, PAL; gingival recession, GR) and intrasurgical (depth of the defect's intraosseous component, IOC; level of the alveolar crest, ACL) parameters were recorded at baseline and at the 1-year re-entry procedure in each experimental site. Furthermore, the coronal level of the newly formed tissue from the base of the defect (NFTL) and the vertical bone gain (VBG) were calculated at the time of membrane removal and after the re-entry procedure respectively. Membranes were removed from both test and control sites after 5 weeks; however, exposure of the membrane always occurred in test sites whereas it was observed in only 6 out of 22 control sites, this fact leading to an incomplete coverage of the regenerated tissue by the gingival flap in 18 out of 22 test sites. In both test and control sites, a statistically significant improvement of clinical and intrasurgical parameters occurred at the end of the study period; however, a significantly greater improvement was observed in control sites for PAL (+4.0 mm versus +3.0 mm; p<0.05) and VBG (3.9 mm versus 2.9 mm; p<0.05) although at the time of membrane removal, NFTL was similar between the experimental sites (test: 5.8; control: 5.6; p>0.05). Conversely, test sites exhibited a statistically significant greater increase in gingival recession (+1.9 versus +1.2; p<0.05) and alveolar crest resorption (-1.1 versus -0.3, p<0.01) in comparison to controls. It was concluded that (1) DRD is a suitable material to be used as a barrier membrane in GTR procedures although (2) e-PTFE membranes can provide a greater improvement in PAL and VBG, probably because of the difficulty in completely covering the regenerated tissue due to the fact that the gingival tissues have undergone a consistent recession in DRD-treated sites. Further studies are needed to demonstrate if an adequate coverage of the regenerated tissue in DRD-treated sites can eliminate these differences.

Generalizability of the added benefits of guided tissue regeneration in the treatment of deep intrabony defects. Evaluation in a multi-center randomized controlled clinical trial

BACKGROUND

Several studies have shown that GTR therapy of intrabony defects results in significantly better outcomes than access flap alone. Most of the available data, however, have been produced in highly controlled research environments by a small group of investigators. Generalizability of results to different clinicians and different subject populations has not been evaluated so far.

METHODS

This parallel group study involved 143 patients recruited in a practice-based research network of 11 offices in 7 countries. It was designed to evaluate: 1) the applicability of the documented added benefits of GTR in the treatment of intrabony defects to different populations, and 2) the generalizability of the expected results to different clinicians. GTR was compared to access flap alone. Defects, one in each patient, were accessed with a previously described papilla preservation flap in both the test and control group. In addition, GTR sites received application of a bioabsorbable poly-D,L-lactide-co-glycolide membrane. A stringent plaque control regimen was enforced in all patients during the 1-year observation period. Outcomes included gains in clinical attachment (CAL) and reductions in probing depth.

RESULTS

Observed gains in CAL were 2.18 +/- 1.46 mm for access flap and 3.04 +/- 1.64 mm for the GTR-treated group. The treatment-associated difference was statistically significant (P = 0.03) after correcting for both center effect and defect anatomy. Among the various centers, a 1.73 mm difference in CAL gain was observed. This is a clinically relevant amount, which underlines the significance of center variability in the outcome of periodontal surgical procedures. A frequency distribution analysis of the obtained CAL gains indicated that GTR treatment of deep intrabony defects decreased, with respect to the access flap control, the probability of obtaining only a modest attachment gain at 1 year. Conversely, CAL gains of 4 mm or more were observed in more than 40% of GTR-treated defects and in less than 20% of the controls (P < 0.0001).

CONCLUSIONS

These data indicate that GTR therapy of deep intrabony defects performed by different clinicians on various patient populations resulted in both greater amounts and improved predictability of CAL gains than access flap alone.

Comparison of 2 regenerative procedures--guided tissue regeneration and demineralized freeze-dried bone allograft--in the treatment of intrabony defects: a clinical and radiographic study

The purpose of this study was to compare clinically and radiographically the effectiveness of guided tissue regeneration (GTR), using a bioabsorbable polylactic acid softened with citric acid ester barrier and commercially available demineralized freeze-dried bone allograft (DFDBA) in the treatment of 2- and 3-wall intrabony defects. Twelve patients each with one treated defect comprised each group. Conservative treatment was completed 2 to 4 months prior to surgery. Clinical measurements, plaque index, gingival index, probing depths (PD), clinical attachment levels (CAL) and recession (REC), were comparable in both groups at baseline. They were repeated at 12 months. Surgical measurements were also comparable at baseline in both groups. In the GTR group, at baseline the mean distance between the cemento-enamel junction (CEJ) and base of the defect was 12.3 +/- 2.9 mm and in the DFDBA group 11.3 +/- 1.8 mm. The defect depth was 6.3 +/- 2.0 mm and 5.4 +/- 1.3 mm, respectively. Radiographs were taken at baseline and 12 months later and compared using non-standardized digital subtraction radiography. In the GTR group, mean PD decreased from 7.9 +/- 2.5 mm to 3.5 +/- 1.4 mm and mean CAL from 10.8 +/- 2.8 mm to 7.0 +/- 1.6 mm, the differences being statistically significant (P = 0.002), while REC increased from 2.9 +/- 1.2 mm to 3.5 +/- 1.1 mm. In the DFDBA group, mean PD decreased from 7.1 +/- 1.1 mm to 3.5 +/- 1.1 mm and mean CAL from 9.8 +/- 1.5 mm to 6.6 +/- 1.7 mm (P = 0.002), while REC increased from 2.8 +/- 1.0 mm to 3.1 +/- 1.2 mm. No significant differences were found when the clinical results of the 2 groups were compared. Radiographic differences between the baseline and reconstructed images 12 months later were observed in both groups. Mean crestal bone resorption was 15.3 +/- 22.5% in the GTR group and 10.4 +/- 31.8% in the DFDBA group, and mean improvement in the distance between the CEJ and the base of the defect was 22.8 +/- 18.1% in the GTR group and 15.3 +/- 13.6% in the DFDBA group. However, the mean improvement in the intrabony depth was larger in the GTR group (71.9 +/- 29.1%) than in the DFDBA group (35.4 +/- 21.6%) (P = 0.007). In conclusion, within the limits of this study, both regenerative procedures were beneficial in treating intrabony defects. No statistical significant differences were observed between the 2 groups, with the exception of radiographic defect resolution which was significantly greater in the GTR group.

Clinical and microbiological evaluation of a bioabsorbable and a nonresorbable barrier membrane in the treatment of periodontal intraosseous lesions

Clinical and microbiological features of periodontal healing in barrier membrane-treated sites were determined in a randomized clinical trial. The study included 10 patients with advanced adult periodontitis and a minimum of one set of similar 2 to 3 wall intraosseous periodontal lesions with no furcation involvement. In each patient, one periodontal lesion was treated with a biodegradable membrane and a contralateral lesion with a nonresorbable barrier membrane. Within the preceding 3 months of regenerative therapy, all patients received full mouth osseous surgery except for the sites for regeneration, were instructed in oral hygiene, and were prescribed systemic ciprofloxacin and metronidazole (250 mg of each, TID, 8 days), starting 7 days before membrane placement. At baseline and at 6 months postsurgery, probing depth and clinical attachment level were assessed in each study site. The subgingival presence of suspected periodontal pathogens was determined by non-selective and selective culture and by DNA probe analyses, and of human cytomegalovirus (HCMV) and Epstein-Barr virus type 1 (EBV-1) by a nested-polymerase chain reaction detection method. At baseline, the barrier-treated sites did not differ significantly in clinical and microbial parameters. Mean baseline probing depth was 7.8+/-1.1 mm for bioabsorbable and 7.9+/-1.3 mm for nonresorbable barrier-treated sites. At 6 months, sites treated with bioabsorbable barrier revealed 4.6+/-1.7 mm gain of clinical attachment (range: 1 to 7 mm) and sites treated with nonresorbable barrier 4.2+/-2.0 mm (range: 1 to 8 mm). The 11 barrier-treated sites that harbored 10% or less bacterial pathogens and were free of HCMV and EBV-1 averaged significantly more clinical attachment gain than the 9 sites that yielded more than 10% bacterial pathogens and/or test viruses (5.6 mm versus 3.0 mm; P=0.005). The present data suggest bioabsorbable and nonresorbable barriers provide similar clinical healing of 2 to 3 wall intraosseous periodontal lesions, emphasize the importance of controlling bacterial pathogens prior to and during periodontal healing, and point to the possible detrimental role of HCMV and EBV-1 in periodontal repair.

Treatment of intrabony defects by different surgical procedures. A literature review

This article reviews studies presented during the last 20 years on the surgical treatment of intrabony defects. Treatments include open flap debridement alone (OFD); OFD plus demineralized freeze-dried bone allograft (DFDBA), freeze-dried bone allografts (FDBA), or autogenous bone; and guided tissue regeneration (GTR). The review includes only studies that presented baseline and final data on probing depths, intrabony defect depths as measured during surgery, clinical attachment level (CAL) gain, and/or bone fill. Some reports were case studies and some controlled studies comparing different treatments. In order to assess what can be accomplished in terms of pocket reduction, clinical attachment level gain, and bone fill with the various treatment modalities, data from studies of each treatment category were pooled for meta-analysis in which the data from and power of each study were weighted according to the number of defects treated. In addition, where there were data for each individual defect treated, these were used for simple regression analysis evaluating the influence of intrabony defect depth on treatment outcome in terms of CAL gain and bone fill. This was done in an effort to assess some predictability of the outcome of the various treatments. OFD alone resulted in limited pocket reduction, CAL gain averaged 1.5 mm and bone fill 1.1 mm. Bone fill, but not CAL gain, correlated significantly to the depth of the defect (R=0.3; P < 0.001), but the regression coefficient was only 0.25. OFD plus bone graft resulted in limited pocket reduction. CAL gain and bone fill averaged 2.1 mm. Bone fill showed a somewhat stronger correlation to defect depth than following OFD alone (R=0.43; P < 0.001) with a regression coefficient of 0.37. GTR resulted in significant pocket reduction, CAL gain of 4.2 mm, and bone fill averaging 3.2 mm. CAL gain and bone fill correlated significantly (P < 0.001) to defect depth (R=0.52 and 0.53 respectively) with the largest regression coefficients (0.54 and 0.58 respectively) among the three treatment modalities. By comparing outcomes following the various treatments it became obvious that to benefit from GTR procedures, the intrabony defect has to be at least 4 mm deep.

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.

A phase I/II clinical trial to evaluate a combination of recombinant human platelet-derived growth factor-BB and recombinant human insulin-like growth factor-I in patients with periodontal disease

The primary objective of this study was to assess the safety of recombinant human (rh) platelet-derived growth factor-BB (PDGF-BB) and (rh) insulin-like growth factor-I (IGF-I) when applied to periodontal osseous defects in humans; a secondary objective was to begin to accrue data on the therapeutic dose of these growth factors (GFs) required to stimulate periodontal regeneration. Thirty-eight human subjects possessing bilateral osseous periodontal lesions were assigned to one of two treatment groups in a split-mouth design. Following full-thickness flap reflection, test sites received local application of the therapeutic drug delivered in coded syringes by a "masked" investigator. Two dose levels were tested, 50 micrograms/ml each of rhPDGF-BB and rhIGF-I in a gel vehicle (LD-PDGF/IGF-I) and 150 micrograms/ml each of rhPDGF-BB and rhIGF-I plus vehicle (HD-PDGF/IGF-I). Control treatment consisted of either conventional periodontal flap surgery or surgery plus vehicle. Safety analyses included physical examination, hematology, serum chemistry, urinalysis, antibody titers, and radiographic evaluation of bony changes. The primary therapeutic assessment was bone fill measured at re-entry 6 to 9 months after treatment. No local or systemic safety issues were found as a result of GF administration. No patients developed antibodies to the rhGF proteins. In subjects treated with LD-PDGF/IGF-I, there were no enhancements in periodontal regeneration compared to controls. However, in patients treated with HD-PDGF/IGF-I, statistically significant increases in alveolar bone formation were noted as measured by surgical re-entry 9 months following drug delivery (P < 0.05). This corresponded to an increase of 2.08 mm of new vertical bone height and 42.3% osseous defect fill in the HD-PDGF/IGF-I subjects versus only 0.75 mm and 18.5% gains in new bone height and osseous fill, respectively, in the controls. Furcation lesions, although limited in number, responded most favorably to treatment, with 2.8 mm horizontal osseous fill. The results from this study suggest that the local application of rhPDGF-BB and rhIGF-I to periodontal lesions is safe at the dose levels studied. LD-PDGF/IGF-I did not elicit increased defect fill compared to the control; however, HD-PDGF/IGF-I resulted in a significant promotion in bone regeneration. Additional studies are warranted to more fully characterize the effects of PDGF/IGF-I on periodontal regeneration in humans.