Deep Intrabony Defects Research Articles

Immunohistochemical investigation on the pattern of vimentin expression in regenerated and intact monkey and human periodontal ligament

The expression of vimentin is well documented in the intact animal and human periodontal ligament (PDL), but there is limited information on the pattern of vimentin expression in the regenerated PDL. The aim of the present study was to investigate the pattern of vimentin expression in the regenerated and intact monkey and human PDL. A total of 12 chronic recession-type defects were created in three monkeys ( Macaca fascicularis) and treated either with guided tissue regeneration (GTR), or with an enamel matrix protein derivative (EMD). After 5 months, the animals were sacrificed and specimens containing the defects and surrounding tissues were dissected free, decalcified in EDTA and embedded in paraffin. Sections were labelled immunohistochemically by using monoclonal antibody against vimentin (VIM 3B4). Twelve patients, each of whom displayed one deep intrabony defect scheduled for extraction were treated with GTR, EMD or combination of EMD+natural bone mineral (NBM). Following a healing period of 6 months, the teeth were extracted “en block” and immunohistochemically analysed according to the same protocol as described in monkeys. The results revealed that in both monkeys and humans the newly formed PDL was labelled similarly for vimentin to the intact (non-treated) PDL. In all specimens, the newly formed PDL was in continuation with the intact parts of PDL, thus suggesting that the mesenchymal cells capable of regenerating the attachment apparatus may have their origin in the intact PDL. In conclusion, the present findings indicate that (a) the reformed PDL displayed a similar expression of vimentin to the intact (original) PDL, and (b) the cells capable of regenerating new PDL and new cementum appear to be of mesenchymal origin and their source may be in the intact PDL.

Enamel matrix proteins in the treatment of deep intrabony defects.

The present study evaluated the healing of enamel matrix derivative (EMD) proteins in the treatment of periodontal lesions with deep intrabony defects. Ten deep intrabony defects in 7 periodontal patients were treated and followed for 1 year. The sites had a probing depth (PD) > or = 8 mm; clinical attachment level (CAL) > or = 9 mm, and intrabony component depth > or = 5 mm. All subjects received therapy prior to surgery and had a plaque score (PI) < or = 10%. Full thickness flaps were elevated buccally and lingually, granulation tissue was removed from the defects, and the root surfaces were planed. A 24% EDTA gel was applied followed by the enamel matrix protein preparation. The flaps were closed with interrupted sutures. The patients rinsed with a chlorhexidine solution twice a day for 6 weeks. They were recalled every 2 weeks for 6 months for professional tooth cleaning and then every 4 weeks for an additional 6 months. The experimental sites were re-examined 6 and 12 months after regenerative surgery. At the 1-year examination, the mean CAL gain was 6.5 mm, the mean PD was 3.2 mm, and mean radiographic bone fill was 4.7 mm. The application of enamel matrix proteins in combination with open flap curettage and root planing resulted in a gain of CAL and bone fill in deep intrabony defects.

Supracrestal soft tissue preservation with enamel matrix proteins in treatment of deep intrabony defects.

The purpose of the present study was to investigate the effectiveness of a regenerative procedure based on supracrestal soft tissue preservation in association with enamel matrix proteins (EMP) in the treatment of deep intrabony defects. The subjects included 35 consecutively treated patients, 23 females and 12 males, aged 28-61 years, 11 of whom were smokers. Patients presented with at least one intrabony defect with probing pocket depth > or = 6 mm and a radiographic depth of the defect > or = 4 mm at the initial visit. Immediately before surgery and 9-12 months after surgery, Local Plaque Score (LPS), Local Bleeding Score (LBS), probing pocket depth (PPD), clinical attachment level (CAL), gingival recession (REC), and radiographic depth of the defect (DEPTH) were recorded. Thirty-one (88.6%) defects were LPS-negative presurgery, while 29 (82.9%) defects presented with no plaque postsurgery. The prevalence of LBS-positive defects shifted from 94.3% presurgery to 8.4% postsurgery (p < 0.0000). PPD was 8.9 mm before surgery, and decreased to 3.5 mm postsurgery (p < 0.0000). CAL varied from 10.1 mm presurgery to 5.4 mm postsurgery (p < 0.0000), with an average improvement (gain) of 4.7 +/- 1.7 mm. Twenty-six (74.3%) defects presented a gain of least 4 mm. Regression analysis showed a positive correlation between CAL gain as a dependent variable, and presurgery PPD and amount of supracrestal soft tissues as predictors. DEPTH improvement (gain) was 3.9 +/- 1.8 mm, which represented 65% of defect fill. Twenty (57.1%) defects presented a DEPTH gain of at least 4 mm. DEPTH gain was significantly correlated to presurgery PPD (p < 0.000). No significant differences were found between smokers and non-smokers in terms of CAL and DEPTH gain. Results from the present study indicated that the regenerative procedure based on supracrestal soft tissue preservation and EMP application leads to clinically and statistically significant improvement of hard and soft tissue conditions of deep intrabony defects.

Clinical Evaluation of an Enamel Matrix Protein Derivative Combined With a Bioactive Glass for the Treatment of Intrabony Periodontal Defects in Humans

The purpose of the present study was to compare the treatment of deep intrabony defects with a combination of an enamel matrix protein derivative (EMD) and a bioactive glass (BG) to BG alone. Twenty-eight patients with chronic periodontitis, each of whom displayed 1 intrabony defect, were randomly treated with a combination of EMD and BG or with BG alone. Soft tissue measurements were made at baseline and at 1 year following therapy. No differences in any of the investigated parameters were observed at baseline between the 2 groups. Healing was uneventful in all patients. At 1 year after therapy, the sites treated with EMD and BG showed a reduction in mean probing depth (PD) from 8.07 +/- 1.14 mm to 3.92 +/- 0.73 mm and a change in mean clinical attachment level (CAL) from 9.64 +/- 1.59 mm to 6.42 +/- 1.08 mm (P < 0.0001). In the group treated with BG, the mean PD was reduced from 8.07 +/- 1.32 mm to 3.85 +/- 0.66 mm and the mean CAL changed from 9.78 +/- 1.71 mm to 6.71 +/- 1.89 mm (P < 0.0001). No statistically significant differences in any of the investigated parameters were observed between the test and control group. Within the limits of the present study, it can be concluded that both therapies led to significant improvements of the investigated clinical parameters, and the combination of enamel matrix derivative and bioactive glass does not seem to additionally improve the clinical outcome of the therapy.

Long-term clinical outcomes of abutments treated with guided tissue regeneration

Statement of problem. Guided tissue regeneration (GTR) is an efficacious and predictable treatment modality for deep intrabony defects around natural teeth and abutments. However, long-term prognosis of abutments treated with regeneration has to be proven. Purpose. This study investigated the long-term stability of clinical outcomes obtained with regeneration in strategically important abutments. Material and methods. Sixteen deep intrabony defects around strategically important abutments in 16 patients were treated according to the principles of GTR. After completion of initial periodontal therapy and placement of long-term provisional fixed partial dentures, nonresorbable membranes were applied. Membranes were removed after 6 weeks. All patients remained in a supervised recall program. Final fixed partial dentures were placed 1 year after surgery. Clinical outcomes were evaluated at 1 year and then 4 to 8 years after surgery. Results. Clinical attachment level gains of 5.3 ± 1.8 mm, reductions in pocket depth (6.1 ± 2 mm), and increases in the percentage of radiographic bone support (31% ± 18%) were observed at 1 year. At long-term follow-up visits, clinical attachment levels remained stable with respect to 1 year (–0.1 ± 0.6 mm; P =.4). The percentage of radiographic bone support slightly increased as compared with 1 year (1% ± 3%, P =.04), and pocket depths (0.8 ± 0.8 mm, P =.004). Conclusions. This study indicated that tooth support can be gained with GTR and maintained over time in patients recalled regularly. (J Prosthet Dent 1999;81:305-11.)

Comparison of Guided Tissue Regeneration Procedure to Conventional Flap Surgery in Treating Intrabony and Class II Furcation Defects, and Analysis of Factors Affecting the Prognosis Following GTR.

The purposes of this study were (1) by means of such a randomized controlled study to compare the effects of the guided tissue regeneration (GTR) procedure with conventional flap surgery (CFS) as a control treatment on the healing of deep intrabony and class II furcation defects, and (2) to determine factors affecting the clinical outcome of the GTR procedure using a multivariate approach.Sixty deep intrabony defects and 20 class II furcation defects were treated in 80 adult periodontitis patients aged from 35 to 60 years. After completion of initial therapy, those defects were assigned to either by a GTR or CFS procedure with matching age, gender, teeth and defect morphology. A postsurgery protocol emphasizing wound stability and infection control was used. Treatment effects were evaluated at 6 months and 1 year postsurgery.Both GTR and CFS for intrabony and furcation defects resulted in a clinically and statistically significant improvement in probing pocket depth (PPD), vertical and horizontal clinical attachm ent level (CAL-V, CAL-H), marginal tissue recession MTR) and radiographic bone loss (BL), at 6 months and 1 year postsurgery compared to baseline measurements. Moreover, there was a more favorable improvement in CAL-V, MTR and BL of the GTR group than in the CFS group at 6 months and 1 year postsurgery for intrabony defects. In addition, the GTR group showed greater improvement in CAL-H than CFS group at both 6 months and 1 year postsurgery for furcation defects. When multivariate analysis assessing the significance of the tested factors in determining the healing outcomes following GTR procedure was performed for intrabony defects, PPD at baseline was of predictive value for vertical clinical attachment gain (CAL-V gain) at 6 months postsurgery, and CAL-V gain and MTR at 6 months postsurgery were of predictive values for CAL-V gain at 1 year postsurgery. BL at baseline and at 6 months postsurgery was also of predictive value for bone fill at 6 months and 1 year postsurgery, respectively. In furcation defects, CAL-H and MTR at baseline were predictive values for horizontal clinical attachment gain (CAL-H gain) at 6 months postsurgery, and CAL-H gain at 6 months postsurgery was of predictive value for CAL-H gain at 1 year postsurgery.These findings suggest that initial PPD and BL in intrabony defects, and initial CAL-H in class II furcation defects might be useful in assessing the regenerative potential of a given site and the degree could be predictive values for a follow-up in tissue of improvement as early as 6 months postsurgery regeneration.

Interproximal Free Gingival Grafts After Membrane Removal in Guided Tissue Regeneration Treatment of Intrabony Defects. A Randomized Controlled Clinical Trial

The purpose of this controlled clinical trial was to compare the efficacy of two surgical approaches to protect the regenerated tissue following membrane removal in guided tissue regeneration (GTR) treated intrabony defects. Twenty-eight (28) defects, one each in 28 patients were randomly assigned after placement of the membrane to one of two treatment groups by blocking to prognostic variables. The test group received free gingival grafts on the interproximal regenerated tissue. In the control group the surgical flaps were coronally positioned over the regenerated tissue. The two groups were well balanced with respect to all prognostic variables. The results indicated that: 1) similar amounts of regenerated tissue were obtained in the two groups at membrane removal (7.6 +/- 2.8 mm, test; 8.3 +/- 2.3 mm, control); 2) a significantly greater amount of probing attachment level gain was observed in the test group (5.0 +/- 2.1 mm, test; 3.7 +/- 2.1 mm, control). This study indicated that placement of free gingival grafts on the interdental regenerated tissue further improves the clinical outcome of GTR in deep intrabony defects.

The Modified Papilla Preservation Technique. A New Surgical Approach for Interproximal Regenerative Procedures

A modification of the papilla preservation technique has been applied to achieve primary closure of the interproximal tissue over barrier membranes placed coronal to the alveolar crest. Fifteen patients with deep intrabony interproximal defects were treated. Defects had a probing attachment level loss of 9.9 +/- 3.2 mm and a recession of the gingival margin of 1.7 +/- 1.6 mm. The depth of the intrabony component was 5.5 +/- 2.9 mm; while the suprabony component was 5.9 +/- 2.0 mm. Titanium-reinforced teflon membranes were placed 1.3 +/- 0.7 mm from the cemento-enamel junction, 4.5 +/- 1.6 mm coronal to the interproximal alveolar bone crest. Primary closure over the interproximal portion of the membrane was obtained in 93% of cases. In 73% of the cases complete coverage of the membrane was maintained until its removal at 6 weeks. These data indicate that the modified papilla preservation technique can be successfully applied to obtain primary closure of the interdental space in regenerative procedures with barrier membranes.

Periodontal regeneration of human intrabony defects. IV. Determinants of healing response.

The purpose of this study was to identify factors which might affect the healing response in intrabony defects treated with guided tissue regeneration. Selected sites presented with deep periodontal lesions with 1, 2, and 3 wall combination intrabony component of 6.1 +/- 2.5 mm. The significance of patient, tooth, and defect characteristics and surgical parameters as predictor variables affecting the regenerative outcome before and following the removal of the barrier membrane was assessed. Outcome was measured as tissue gain under the membrane, regenerated probing attachment level (PAL), and bone fill. The total depth of the intrabony component and the radiographic defect angle significantly affected the amount of tissue gain. Seventy-five percent (75%) of the variability of regenerated PAL and bone fill was explained in terms of tissue gain under the membrane, radiographic width of the defect angle, full mouth bleeding score, and presence or absence of flap coverage of the newly formed tissue. Control of the identified predictor variables might improve the extent and predictability of guided tissue regeneration in the treatment of deep intrabony defects.