Healing after treatment of periodontal intraosseous defects. VI. Factors influencing the healing response

Bioactive Glasses in Periodontal Regeneration A Systematic Review

Bioactive glasses (BAGs) are surface-active ceramic materials that can be used in bone regeneration due to their known osteoconductive and osteoinductive properties. This systematic review aimed to study the clinical and radiographic outcomes of using BAGs in periodontal regeneration. The selected studies were collected from PubMed and Web of Science databases, and included clinical studies investigating the use of BAGs on periodontal bone defect augmentation between January 2000 and February 2022. The identified studies were screened using Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. A total of 115 full-length peer-reviewed articles were identified. After excluding duplicate articles between the databases and applying the inclusion and exclusion criteria, 14 studies were selected. The Cochrane risk of bias tool for randomized trials was used to assess the selected studies. Five studies compared using BAGs with open flap debridement (OFD) without grafting materials. Two of the selected studies were performed to compare the use of BAGs with protein-rich fibrin, one of which also included an additional OFD group. Also, one study evaluated BAG with biphasic calcium phosphate and used a third OFD group. The remaining six studies compared BAG filler with hydroxyapatite, demineralized freeze-dried bone allograft, autogenous cortical bone graft, calcium sulfate β-hemihydrate, enamel matrix derivatives, and guided tissue regeneration. This systematic review showed that using BAG to treat periodontal bone defects has beneficial effects on periodontal tissue regeneration. OSF Registration No.: 10.17605/OSF.IO/Y8UCR.

Periodontal Regenerative Therapy Using rhFGF-2 and Deproteinized Bovine Bone Mineral versus rhFGF-2 Alone: 4-Year Extended Follow-Up of a Randomized Controlled Trial

The aim of this study was to evaluate longitudinal outcomes of recombinant human fibroblast growth factor (rhFGF)-2 plus deproteinized bovine bone mineral (DBBM) therapy in comparison with rhFGF-2 alone for treating periodontal intrabony defects. This study describes 4-year follow-up outcomes of the original randomized controlled trial. Intrabony defects in periodontitis patients were treated with rhFGF-2 (control) or rhFGF-2 plus DBBM (test). Clinical, radiographic, and patient-reported outcome (PRO) measures were used to evaluate the outcomes. Thirty-two sites were able to be followed up. At 4 years postoperatively, clinical attachment level (CAL) gains in the test and control groups were 3.5 ± 1.4 mm and 2.7 ± 1.4 mm, respectively, showing significant improvement from preoperative values but no difference between groups. Both groups showed an increase in radiographic bone fill (RBF) over time. At 4 years, the mean value for RBF in the test group (62%) was significantly greater than that in the control group (42%). In 1-2-wall defects, the test treatment yielded significantly greater RBF than the control treatment. No significant difference in PRO scores was noted between the groups. Although no significant difference in CAL gain was found between the groups at the 4-year follow-up, the combination treatment significantly enhanced RBF. Favorable clinical, radiographic outcomes, and PRO in both groups can be maintained for at least 4 years.

Clinical and radiographic evaluation of 0.8% hyaluronic acid as an adjunct to open flap debridement in the treatment of periodontal intrabony defects: randomized controlled clinical trial

OBJECTIVES

Present study aimed to evaluate and compare the clinical and radiographic efficacy of 0.8% hyaluronic acid (HA) gel as an adjunct to open flap debridement (OFD) versus open flap debridement (OFD) alone in the treatment of periodontal intrabony defects.

MATERIALS AND METHODS

This randomized, controlled, split-mouth, clinical trial included 20 chronic periodontitis (stage II or III (grades A to B)) patients, having at least two contralateral intrabony defects. Forty bilateral intrabony defects (20 in each group) were randomly divided into test (0.8% HA gel + OFD) and control (OFD + placebo) groups. Clinical parameters evaluated at baseline, 6-months, and 12-months were plaque index (PI), gingival index (GI), probing depth (PD), clinical attachment level (CAL), and gingival recession (GR). Using cone beam computed tomography (CBCT), radiographic parameters were evaluated at baseline and 12 months. This included bone defect fill (DF), alveolar crest changes (ACC), and defect resolution (DR). CAL served as the primary outcome variable.

RESULTS

After 12 months, the test group showed significantly greater CAL gain (5.1 ± 1.2 versus 4.05 ± 1.19 mm) and bone defect fill (DF) (5.67 ± 2.01 versus 4.49 ± 1.78 mm) compared to the control group. Mean PD reduction in the test group (5.3 ± 1.2 versus 4.35 ± 0.81 mm) was statistically significant compared to the control group at 12-month period. The control group showed statistically significant increase in GR (1.2 ± 0.76 versus 0.7 ± 0.73 mm) compared to the test group after 12 months.

CONCLUSION

Application of hyaluronic acid gel in conjunction with open flap debridement resulted in enhanced clinical and radiographic outcomes compared to open flap debridement alone.

CLINICAL RELEVANCE

Adjunctive application of HA gel in open flap debridement may improve clinical and radiographic outcomes.

CLINICAL TRIAL REGISTERED NUMBER

CTRI/2018/03/012334.

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.

Five years clinical results following treatment of human intra-bony defects with an enamel matrix derivative: a randomized controlled trial

INTRODUCTION

Emdogain® represents an extracellular matrix derivative that controls and promotes periodontal regeneration. Several studies have demonstrated that the treatment of periodontal defects with Emdogain® leads to improvements in clinical parameters. However, long-time clinical trials establishing clinical usefulness of Emdogain® are scarce. Therefore, the present randomized split mouth, controlled study was undertaken to evaluate the effectiveness of Emdogain® as an adjunct to open flap debridement for the treatment of intra-bony defects over a period of 5 years.

MATERIALS AND METHODS

The study population consisted of 15 chronic periodontitis patients with bilateral interproximal osseous defects. The test group was treated by open flap debridement with EDTA 24% (PrefGel®) followed by enamel matrix derivative (Emdogain®). The control group was treated by open flap debridement with EDTA 24% (PrefGel®).

RESULTS

After 1 and 5 years, both the test and control groups showed significant mean PPD reduction. A greater reduction in mean Probing Pocket Depth (PPD) was observed in the test group (3.84 ± 1.05) as compared to the control group (1.92 ± 0.35). The mean Clinical Attachment Level (CAL) gain of 3.18 ± 0.87 mm was observed in the test group, while the control group displayed mean CAL gain of 1.60 ± 0.54 mm. The observed differences were found to be statistically significant in both the groups (p < 0.05). Percentage bone fill was significantly increased at 12 months post-surgery in test group (66.66 ± 7.8%) as compared to control group (31.71 ± 4.1%).

CONCLUSION

The treatment with Emdogain resulted in a significantly higher CAL gain and PPD reduction in comparison with OFD and PrefGel®.

Clinical evaluation of porous hydroxyapatite bone graft (Periobone G) with and without collagen membrane (Periocol) in the treatment of bilateral grade II furcation defects in mandibular first permanent molars

BACKGROUND

Furcation invasions represent one of the most demanding therapeutic challenges in periodontics. This investigation assessed and compared the clinical efficacy of hydroxyapatite bone graft material when used alone and with collagen membrane in the treatment of grade II furcation defects.

MATERIALS AND METHODS

Ten patients with comparable bilateral furcation defects in relation to mandibular first molars were selected and treated in a split-mouth design. After the hygiene phase of therapy was completed, the groups were selected randomly either for treatment with hydroxyapatite bone graft (Periobone G) alone or with a combination of bone graft and guided tissue regeneration (GTR) membrane (Periocol). Clinical parameters like plaque index, gingival index, vertical probing depth, horizontal probing depth, clinical attachment level, position of marginal gingiva, and the amount of bone fill were used at baseline and at 3 and 6 months postoperatively.

RESULTS

At 6 months, both surgical procedures resulted in statistically significant reduction in vertical and horizontal probing depths and gain in the clinical attachment level.

CONCLUSION

The use of combination technique yielded superior results compared to sites treated with bone graft alone. However, the difference was not statistically significant.

Interproximal periodontal defect model in dogs: a pilot study

OBJECTIVE

This study aimed to evaluate the validity of a surgically created interproximal periodontal defect in dogs.

MATERIALS AND METHODS

Surgery was performed in the interproximal area between the maxillary second and third premolars in two beagle dogs. Following an incision and reflection of the gingival flap, a 3-mm wide and 5-mm high defect was prepared surgically at the interproximal area. A thorough root planing was performed and the flap was coronally positioned and sutured. The contra-lateral area was served as the control with no surgical intervention. After 8 weeks of healing, the animals were killed and the defect was analysed histometrically and radiographically.

RESULTS

The interproximal periodontal defect resembled a naturally occurring defect and mimicked a clinical situation. After healing, the defect showed limited bone (0.89±0.02mm) and cementum regeneration (1.50± 0.48mm).

CONCLUSIONS

Within the limitations of this pilot study, the interproximal periodontal defect showed limited bone and cementum regeneration. Thus, it can be considered as a standardized, reproducible defect model for testing new biomaterials.

Partial least squares path modelling for relations between baseline factors and treatment outcomes in periodontal regeneration

BACKGROUND

Some clinical outcome variables in periodontal research are mathematically coupled, and it is not feasible to include all the mathematically coupled variables in an ordinary least squares (OLS) regression analysis. The simplest solution to this problem is to drop at least one of the mathematically coupled variables. However, this solution is not satisfactory when the mathematically coupled variables have distinctive clinical implications.

MATERIAL AND METHODS

Partial least squares (PLS) methods were used to analyse data from a study on guided tissue regeneration. Relationships between characteristics of baseline lesions and treatment outcomes after 1 year were analysed using PLS, and the results were compared with those from OLS regression.

RESULTS

PLS analysis suggested that there were multiple dimensions in the characteristics of baseline lesion: vertical dimension was positively associated with probing pocket depth (PPD) reduction and clinical attachment level (CAL) gain, whilst horizontal dimension was negatively associated with the outcome. Baseline gingival recession had a negative association with PPD reduction but a small positive one with CAL gain.

CONCLUSION

PLS analysis provides new insights into the relationships between baseline characteristics of infrabony defects and periodontal treatment outcomes. The hypothesis of multiple dimensions in baseline lesions needs to be validated by further analysis of different datasets.

Periodontal and endodontic regeneration

Guided tissue regeneration (GTR) is effective in halting tissue and bone destruction and promoting new tissue and bone formation. Although the goal of complete and predictable regeneration still remains elusive, many techniques and materials have been developed that show good clinical and histologic outcomes. The most commonly used materials in GTR include bone replacement grafts from numerous sources, nonresorbable and bioabsorbable membranes, and recently growth hormones/cytokines and other host modulating factors. This article reviews the biologic rationale behind current techniques used for tissue/bone regeneration, reviews the most common materials and techniques, and attempts to explain the factors that influence the outcomes of these therapies.

Comparison of injectable calcium phosphate bone cement grafting and open flap debridement in periodontal intrabony defects: a randomized clinical trial

BACKGROUND

Regeneration of lost periodontium is the ultimate goal of periodontal therapy. Bone grafts, guided tissue regeneration, and application of growth factors are used for periodontal regeneration. This study aimed to evaluate the clinical efficacy of a new, injectable calcium phosphate bone cement (CPC) in human periodontal intrabony defects.

METHODS

Thirty subjects (mean age, 53.4 +/- 9.1 years) with periodontitis and narrow intrabony defects were enrolled in the study. Subjects were classified randomly into the CPC graft group (N = 15) or the open flap debridement (OFD) alone group (N = 15). Clinical measurements were performed at baseline and at 3, 6, 9, and 12 months; radiographs were taken at baseline, 2 weeks, and 6 and 12 months after surgery. The Student t test was used for statistical analysis.

RESULTS

In the CPC group, six cases showed exposure or loss of the CPC within 12 months, whereas the remaining nine cases (CPC-R group) showed no adverse reaction, including infection or suppuration. Overall, CPC-R and OFD treatment groups exhibited a significant reduction in probing depth and a significant gain in clinical attachment level at 3, 6, 9, and 12 months compared to baseline values. However, there were no significant differences in any of the clinical parameters between the groups. In the CPC-R group, radiographic bone level gain appeared to be greater than in the OFD group.

CONCLUSIONS

The present study failed to demonstrate any superior clinical outcomes for the CPC group compared to the OFD group; however, radiographs revealed more favorable results in the CPC-R group. The filling volume and stiffness of CPC may compromise the clinical outcomes for periodontal intrabony defects.

Effectiveness of proliferating tissues in combination with bovine-derived xenografts to intrabony defects of alveolar bone in dogs

The aim of this study was to investigate the effect of proliferating tissue used in combination with bovine-derived xenograft (BDX) on the formation of new cementum and bone in dogs. Intrabony defects were treated with either BDX in conjunction with autogenous proliferating tissues (BDXplus-proliferating tissues: BDX-P group) or BDX alone (BDX-alone group). The control group received no BDX or proliferating tissues. The animals were sacrificed after 2, 4, and 8 weeks of the treatment, and tissues were histologically examined. Specimens from the control group were characterized by long junctional epithelium and little bone formation. The BDX-P group showed a statistically significant increase in new bone and cementum formation compared to the BDX-alone group (30.9% vs. 18.7, p < 0.01 and 87.8% vs. 61.8, p < 0.01). The ratio of proliferating cell nuclear antigen (PCNA)-positive cells in the newly formed connective tissue of the BDX-P group was significantly greater than that in the BDX-alone group. These findings suggest that the use of proliferating tissues in combination with BDX enhances new bone and cementum formation, offering potential as therapeutic material in periodontal regeneration.

Favorable Periodontal Healing of 1-Wall Infrabony Defects After Application of Calcium Phosphate Cement Wall Alone or in Combination With Enamel Matrix Derivative: A Pilot Study With Canine Mandibles

BACKGROUND

Although various periodontal regenerative therapies are used, their effects on non-contained infrabony defects are unpredictable. Our previous studies showed that injectable, moldable, fast-setting calcium phosphate cement (CPC) promoted histocompatible periodontal healing in 3-wall intrabony defects. The present study evaluated healing patterns after surgical application of CPC walls with and without an enamel matrix derivative (EMD) in 1-wall infrabony defects in dogs.

METHODS

One-wall infrabony defects (5 x 5 x 4 mm) were created surgically on the mesial and distal sides of bilateral mandibular fourth premolars in four beagle dogs. After elevating a full-thickness flap, exposed root surfaces were planed thoroughly. The 16 defects were assigned randomly to one of the following experimental conditions: CPC, CPC+EMD, EMD, and open flap debridement (OFD). Ten weeks post-surgery, the animals were sacrificed, and histologic specimens were prepared for histomorphometric evaluation.

RESULTS

Defect sites treated with EMD only exhibited varying degrees of new cementum and new bone formation, whereas the OFD group presented only limited new cementum and bone formation. Defect sites where a CPC wall was implanted (CPC and CPC+EMD groups) revealed significantly greater regeneration of new bone and new cementum than in the EMD and OFD groups. No significant differences were observed between the CPC and CPC+EMD groups.

CONCLUSIONS

CPC walls with and without EMD promoted regeneration of alveolar bone and cementum in 1-wall infrabony defects. Space and stable wound healing are believed to be crucial for periodontal regeneration in non-contained infrabony defects.

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.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Effects of pretreatment clinical parameters on bioactive glass implantation in intrabony periodontal defects

BACKGROUND

The various methods for regeneration of periodontal tissue that have been developed can be classified into guided tissue regeneration and bone implantation. Since the implantation materials have shown both deficiencies and merits, dentists have begun exploring the bioactive glass first used in plastic surgery. This paper examines the effectiveness of this new material on periodontal intrabony defects.

METHODS

Clinical effects of bioactive glass implantation in intrabony periodontal defects were evaluated 6 months after surgery in 38 intrabony defects from 38 patients with chronic periodontitis. Twenty-one experimental defects received bioactive glass implantation (test group), while 17 control defects were treated with a flap procedure only (control group). The criteria for comparative observation were preoperative and postoperative probing depth (PD), clinical attachment level (CAL), bone probing depth (BPD), and gingival recession.

RESULTS

Reductions in PD were observed in both groups (P<0.01). The reduction in PD was significantly greater in the test group when preoperative PD exceeded 7 mm (P<0.01). Improvements in CAL were also observed in both groups (P<0.01), with the test group showing significantly greater gains (P<0.05). In those cases where preoperative CAL was less than 7 mm, there was no statistically significant difference between the two groups. Reduction in BPD was observed in both groups, with the test group showing significantly greater reduction (P <0.01). There was no significant difference in BPD change, however, when preoperative BPD was < or =7 mm. Significantly greater reduction of BPD in the test group was observed when intrabony defect depth was >4 mm (P <0.05). Significant improvements in PD, CAL, and BPD were noted in the test group when the crestal involvement exceeded 100 degrees. Correlation test between various clinical parameters indicated that greater changes in PD and CAL in the test group were observed when preoperative CAL was large (P<0.001), and greater changes in PD (P<0.05), CAL (P<0.01), and BPD (P<0.05) were noted when preoperative BPD was large. Correlation between crestal involvement and CAL change was noted only in the control group (P<0.01). High correlations were observed between PD changes and CAL changes and between CAL changes and BPD changes in both groups.

CONCLUSIONS

Use of a bone substitute in a flap operation resulted in significantly greater improvements in CAL and BPD over flap operation alone and seemed to have positive effects in postoperative PD, CAL, and BPD in those cases with more severe preoperative CAL and BPD.

A comparative study utilizing open flap debridement with and without enamel matrix derivative in the treatment of periodontal intrabony defects: a 12-month re-entry study

BACKGROUND

Previous studies have demonstrated that enamel matrix derivative (EMD) has the ability to improve clinical parameters when used to treat intraosseous defects. The purpose of the present study was to compare at 12 months postsurgery sites treated with open flap debridement (OFD) alone to those treated with OFD and EMD.

METHODS

Twenty-three subjects with at least 2 intrabony defects were chosen. Fifty-three defects received EMD in conjunction with OFD. Thirty-one defects in these same 23 subjects were treated with OFD alone. Stents were fabricated to serve as fixed reference points. Re-entries were performed at least 1 year after initial surgery. Soft tissue measurements were recorded prior to initial surgery and prior to re-entry for gingival (GI) and plaque (PI) indices, probing depth (PD), gingival margin position, and clinical attachment level (CAL). Hard tissue measurements were recorded during the initial and re-entry surgery for level of crestal bone and depth of defect. Statistical analysis was conducted using the method of generalized estimating equations to determine changes in GI, PI, PD, CAL, fill of the osseous defect, and crestal resorption. Percent of defect fill was also calculated.

RESULTS

In all categories, treatment with EMD (test) was superior to treatment without EMD (control). Average PI and GI were not significantly different either initially or prior to re-entry. The average PD reduction was 2.7 mm greater with EMD than controls. The average CAL gains were 1.5 mm greater, and the average fill of osseous defect 2.4 mm greater with EMD than controls. The average percent of defect fill after adjusting for crestal bone loss was more than 3 times greater for EMD versus control-treated sites (74% defect fill with EMD versus 23% defect fill for control sites).

CONCLUSIONS

This study indicates that treatment of periodontal intraosseous defects with EMD is clinically superior to treatment without EMD (open flap debridement) in every parameter evaluated. Re-entry data demonstrate that percent fill of osseous defects treated with EMD compares favorably with the treatment results utilizing bone grafts or membrane barriers, according to published literature.

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.

Comparison of bioactive glass synthetic bone graft particles and open debridement in the treatment of human periodontal defects. A clinical study

The purpose of this study was to compare the repair response of bioactive glass synthetic bone graft particles and open debridement in the treatment of human periodontal osseous defects. Fifty-nine defects in 16 healthy adults were selected. Each patient had at least 2 sites with attachment loss of at least 6 mm with clinical and radiographic evidence of intrabony or furcation defects. One to 3 months after cause-related therapy (oral hygiene instructions, scaling and root planing), the following measurements were recorded prior to surgery: probing depths, clinical attachment level, and gingival recession. Each defect was surgically exposed and measurements made of the alveolar crest height and base of osseous defect. The test defects were implanted with bioactive glass. The other sites served as unimplanted controls. Flaps were sutured at or close to the presurgical level. Radiographs and soft tissue presurgical measurements were repeated at 6, 9, and 12 months. At 12 months all sites were surgically re-entered to record osseous measurements. At the 12-month evaluation, significantly greater mean probing depth reduction was noted in the bioactive glass group compared to the controls (4.26 mm versus 3.44 mm; P = 0.028). Clinical attachment level gain was significantly improved (P = 0.0004) in the bioactive glass sites (2.96 mm) compared to the control sites (1.54 mm). There was significantly less gingival recession in the bioactive glass sites (1.29 mm) compared to the control sites (1.87 mm). Defect fill was significantly greater in the bioactive glass sites (3.28 mm) compared to the control sites (1.45 mm). Defect depth reduction was significantly greater in the bioactive glass sites (4.36 mm) compared to the control sites (3.15 mm). In conclusion, bioactive glass showed significant improvement in clinical parameters compared to open flap debridement.

Retrospective analysis of factors related to clinical outcome of guided tissue regeneration procedures in intrabony defects

The purpose of this retrospective study was to determine factors affecting clinical outcome of guided tissue regeneration (GTR) in the treatment of intrabony periodontal defects. 38 patients each contributing 1 isolated intrabony defect treated with GTR were included in this analysis. Patient and defect characteristics, and defect-specific recordings relative to clinical outcome 6 months postsurgery were assessed. GTR treatment resulted in clinically and statistically significant improved probing depths (PD), clinical attachment levels (CAL), and probing bone levels (PBL). Presurgery PD and PBL were of predictive value for CAL gain and PBL gain, respectively. CAL and PBL gain did not correlate to defect depth or configuration. Cigarette smoking exhibited a highly significant negative correlation to parameters of clinical outcome.

Periodontal regeneration around natural teeth

1. Evidence is conclusive (Table 2) that periodontal regeneration in humans is possible following the use of bone grafts, guided tissue regeneration procedures, both without and in combination with bone grafts, and root demineralization procedures. 2. Clinically guided tissue regeneration procedures have demonstrated significant positive clinical change beyond that achieved with debridement alone in treating mandibular and maxillary (buccal only) Class II furcations. Similar data exist for intraosseous defects. Evidence suggests that the use of bone grafts or GTR procedures produce equal clinical benefit in treating intraosseous defects. Further research is necessary to evaluate GTR procedures compared to, or combined with, bone grafts in treating intraosseous defects. 3. Although there are some data suggesting hopeful results in Class II furcations, the clinical advantage of procedures combining present regenerative techniques remains to be demonstrated. Additional randomized controlled trials with sufficient power are needed to demonstrate the potential usefulness of these techniques. 4. Outcomes following regenerative attempts remain somewhat variable with differences in results between studies and individual subjects. Some of this variability is likely patient related in terms of compliance with plaque control and maintenance procedures, as well as personal habits; e.g., smoking. Variations in the defects selected for study may also affect predictability of outcomes along with other factors. 5. There is evidence to suggest that present regenerative techniques lead to significant amounts of regeneration at localized sites on specific teeth. However, if complete regeneration is to become a reality, additional stimuli to enhance the regenerative process are likely needed. Perhaps this will be accomplished in the future, with combined procedures that include appropriate polypeptide growth factors or tissue factors to provide additional stimulus.

A clinical evaluation of demineralized freeze-dried bone allograft in combination with tetracycline in the treatment of periodontal osseous defects

The purpose was to evaluate the use of demineralized freeze-dried bone allograft reconstituted with 50 mg/ml tetracycline hydrochloride in the treatment of intrabony periodontal defects. Fifteen systemically healthy patients (12 females, 3 males; aged 35 to 61) with moderate-advanced periodontitis were treated. Patients had 3 osseous defects with probing depths (PD) > 5 mm after initial therapy. Each site in each subject was randomly assigned to one of the following groups: 1) demineralized freeze-dried bone allograft reconstituted with 50 mg/ml tetracycline (DFDBA + TCN); 2) demineralized freeze-dried bone allograft alone (DFDBA); or 3) debridement only (D). Clinical measurements were taken the day of surgery, 6 months, and 1 year. Standardized radiographs were taken at baseline and 1 year and were evaluated by computer assisted densitometric image analysis (CADIA). Clinical measurements included gingival recession, PD, clinical attachment level, and mobility. Osseous defect measurements were taken at baseline and at the 1 year reentry. No adverse healing responses occurred. The results showed that all patients had a statistically significant improvement in probing depth and attachment level at 1 year. Osseous measurements showed bone fill of 2.27 mm (51.6%) for the DFDBA + TCN group, 2.20 mm (52.4%) for the DFDBA group, and 1.27 mm (32.8%) for the D group. Defect resolution was 77.3% for the DFDBA + TCN group, 77.9% for the DFDBA group, and 63.8% for the D group. The mean CADIA values were 5.04 for the DFDBA + TCN group, 6.79 for the DFDBA group and 2.78 for the D group. The CADIA values did not correlate with the clinical parameters. Although the grafted groups showed greater bone fill and defect resolution, there was no statistically significant difference in any of the clinical parameters between the treatment groups. This study suggests that there is no significant benefit from reconstituting the allograft with 50 mg/ml of tetracycline hydrochloride.

Treatment of periodontal furcation defects. Coronally positioned flap with or without citric acid root conditioning in class II defects

A total of 27 mandibular, buccal class II furcation defects were treated in 16 subjects using a coronally positioned flap procedure, with or without citric acid conditioning of the root surfaces. The effect of the therapies was evaluated from a series of soft and hard tissue measurements. Mean improvements were slightly greater for acid treated than for non-acid treated defects. However, none of the mean differences reached statistical significance, indicating that citric acid conditioning may not be a necessary part of the regenerative, coronally positioned flap procedure in mandibular furcations.

Gingivectomy versus flap surgery: the effect of the treatment of infrabony defects. A clinical and radiographic study

The aim of this paper was to compare the short-term results of gingivectomy (GV) and modified Widman flap (MWF) surgery in the treatment of infrabony defects. 14 patients with 68 bilateral infrabony defects were selected. At baseline, and 3 and 6 months postoperatively, assessments of oral hygiene, gingival conditions, bleeding on probing, probing pocket depth and attachment level, were recorded. Conventional radiograps were obtained in a way that assured a reproducible projection geometry. In a split-mouth design, one jaw quadrant was randomly treated with GV, while the contralateral with a MWF. The changes of the bone tissue were assessed by means of conventional and subtraction images by 2 observers. The interobserver agreement of the conventional and subtraction technique was studied. The majority of the sites demonstrated a significant improvement in gingival conditions and a reduction in bleeding. For both treatments, probing depths were reduced by an average of 3 mm, while a mean of 1.22-1.35 mm of probing attachment gain was obtained. The GV resulted in slightly more gingival recession (1.90 mm) than the MWF (1.60 mm). The radiographic examination demonstrated gain of bone in 7 defects treated with GV and in 9 defects treated with MWF. This study demonstrated that pockets associated with infrabony defects can be successfully treated by both treatment modalities. Furthermore, bone gain can occur after treatment but not in a predictable manner.

Treatment of periodontal furcation defects. Coronally positioned flaps versus dura mater membranes in class II defects

Mandibular class II furcation defects in 19 subjects were treated using 2 different methods of wound closure. In 16 of the defects, the wound was closed with a coronally positioned surgical flap secured by crown-attached sutures. In 15 of the defects, a collagenous membrane (freeze-dried dura mater) was placed to cover the exposed defect, followed by suturing of the surgical flap at the level of the alveolar crest. After use of a coronally positioned flap, an average of 70% of the defect volume became filled with bone, with complete closure by bone fill for 9 of the 16 treated defects. After use of dura mater membrane, 38% of the defect volume was filled with bone, with complete bony closure for 3 of the 15 treated defects. The results following use of coronally positioned flaps support our previous findings and the potentials of this technique. The results following use of dura mater membranes, together with recently reported risk for spread of virus with dura implants, do not justify the use of dura mater for these regenerative purposes.

Relationship between the radiographic periodontal defect angle and healing after treatment

This study radiographically evaluated the correlation between the changes in alveolar bone level occurring in bony defects after periodontal therapy and the corresponding pretreatment defect angles. The defect angle was defined by the bony defect surface and the root surface. The changes were determined from identically exposed and processed radiographs obtained just prior to surgery and 15 to 18 months later. The defect angle was clearly correlated to the radiographic changes in alveolar bone level. Most defects with an angle less than 45 degree showed a gain of bone while defects with the largest defect angles showed a loss. In addition, defects on root surfaces without furcations showed better healing than defects associated with furcations.

Treatment of intraosseous periodontal defects with a combined adjunctive therapy of citric acid conditioning, bone grafting, and placement of collagenous membranes

A total of 25 proximal, intraosseous periodontal defects were treated in 21 adult patients. A 3-prong adjunctive, regenerative treatment approach was used. The treatment included (1) citric acid conditioning of the root surfaces, (2) grafting of particles of decalcified, freeze-dried homologous bone, and (3) placement of freeze-dried, homologous dura mater sheets between the replaced surgical flaps and the tooth surfaces. The results, as evaluated by probing attachment and probing bone level measurements, during 1 year of observation, demonstrated limited improvements of the treated defects. The limited results were similar to previous observations in our clinics following treatment of intraosseous defects using different treatment modalities. It appears that new treatment approaches need to be sought to accomplish clinically significant and predictable regeneration in proximal, intraosseous periodontal defects.

Treatment of periodontal furcation defects. (II). Bone regeneration in mandibular class II defects

A total of 30 mandibular, buccal class II furcation defects were treated in 22 subjects using a regenerative surgical therapy that included citric acid root conditioning and coronally positioned flaps secured by crown-attached sutures. In addition, grafts of freeze-dried, decalcified allogenic bone were placed in 16 of the 30 defects. The effect of the therapies was evaluated from a series of soft and hard tissue measurements. These measurements demonstrated notable improvement 12 months following therapy. On the average, 67% of the defect volume became filled with bone. 43% of treated defects were completely closed by bone fill. No difference was observed between defects treated with and without bone grafts.

On the bias caused by regression toward the mean in studying the relation between change and initial value

In studies of treatment effects in clinical trials and longitudinal followup investigations, it is not unusual to inquire as to whether a relationship exists between the change of a variable and its initial value, for example pocket depth Such studies must be carried out with great care, since the results are biassed by the regression towards the mean (RTM) effect. Examples are presented, the magnitude of the RTM effect is estimated and means of dealing with the RTM problem are discussed. RTM also appears as a selection phenomenon, emphasizing the need to include control groups in order to make possible adjustments for the bias caused by RTM.

Healing after treatment of periodontal intraosseous defects. III. Effect of osseous grafting and citric acid conditioning

The present study was performed to determine whether the healing of periodontal intraosseous defects could be improved through the combined use of citric acid conditioning of the root surfaces and grafting of autogenous intraoral cancellous bone. 28 proximal defects in 19 patients were treated surgically including acid conditioning of the root surfaces. Another 25 defects in these patients were treated with acid conditioning combined with osseous grafts using the maxillary tuberosity areas as donor sites. Both therapies, e.g., citric acid conditioning alone and acid conditioning combined with osseous grafting resulted in approximately 1 mm gains of probing attachment and probing bone levels. Within the parameters of this study, osseous grafting did not enhance the effect of citric acid conditioning alone. Limited improvement of the treated defects of the present study was obtained in spite of the use of supplementary regenerative techniques.