Periodontal regeneration of intrabony defects with resorbable and non-resorbable membranes: 30-month results

Abstract The aim of this prospective split-mouth-study was to compare the healing results in intrabony defects 12 and 30 months after placement of resorbable (polyglactin-910) and non-resorbable (e-PTFE) GTR-membranes. 11 healthy patients with 30 defects participated. 10 patients with 10 pairs of contralateral lesions, which were treated with both membrane types, were included in the split-mouth-design. Furthermore, in an additional group-design all 30 (16 polyglactin-910 and 14 e-PTFE) treated sites were evaluated. Clinical examinations (PBI, REC, PPD, PAL) and radiographic examinations were carried out under standardized conditions immediately before as well as 12 and 30 months after surgery. Additionally, for the assessment of the effectiveness of the 2 membranes by comparing the regeneration results of different defects, the vertical relative attachment gain (V-rAG) was calculated as a% of the PAL gain related to the maximum possible attachment gain (expressed by the baseline depth of the osseous defect intraoperatively measured). Digital subtraction radiography (DSR) was carried out for the quantitative assessment of bone density changes due to GTR. In the split-mouth-design, both types of membranes provided significant V-rAGs (median) after 12 months (polyglactin: 81.7%: e-PTFE: 100.0%) and after 30 months (polyglactin: 69.1%: e-PTFE: 83.8%) compared to baseline. In 90.0% of the polyglactin and e-PTFE sites, a probing attachment gain of at least 2 mm was maintained over the 30-month period. However, in 2 polyglactin treated sites, and 5 e-PTFE treated sites, a new attachment loss was found between 12 and 30 months. DSR showed bone density gain 12 and 30 months postsurgically. No statistically significant differences could be observed between the 2 membrane materials with regard to clinical and radiographic findings. This was confirmed when considering the total number of defects (group-design). In conclusion, based on this 30-month-study resorbable polyglactin membranes may be regarded as a useful alternative to the well established e-PTFE membranes for the treatment of intrabony defects.     

Regenerative surgery of intrabony periodontal defects using ePTFE barrier membranes: scanning electron microscopic evaluation of retrieved membranes versus clinical healing.

Sixteen intrabony defects in 12 patients were treated by gingival flap surgery including root surface debridement and placement of an expanded polytetrafluoroethylene (ePTFE) membrane. The membranes were removed after 4 to 6 weeks and examined by scanning electron microscopy (SEM) for bacterial contamination and adherent connective tissue elements. Twelve months postsurgery, the defect sites were reexamined for changes in probing attachment level and probing bone level. Comparison of ultrastructural findings and clinical observations revealed that extent of bacterial contamination of the membrane correlated inversely with clinical assessment of attachment gain. The results indicate that the extent of oral exposure and bacterial contamination of the ePTFE membrane at the time of removal may be an indicator of the long-term success or failure of the regenerative procedure.     

Factors affecting the healing response of intrabony defects following guided tissue regeneration and access flap surgery

Abstract Identification and control of significant factors determining clinical outcomes is of paramount importance to improve expected results of a variety of therapeutic procedures. The aim of this investigation was to identify, with a multivariate approach, factors associated with healing outcomes of 3 penodontal surgical procedures in deep intrabony defects. 45 patients with evidence of deep intrabony defects were randomly assigned to 3 treatment groups: access flap (group C), conventional guided tissue regeneration (GTR) with non-resorbable expanded polytetrafluoroethilene (ePTFE) membranes (group B), and GTR with self supporting membranes combined with the modified papilla preservation technique (group A). In both GTR procedures, membranes were positioned coronal to the interproxymal alveolar crest. Primary outcome variables (i.e., probing attachment level gains at 1 year and the amount of newly formed tissue present at membrane removal) were explained in terms of a series of patient, defect morphology and surgical factors, using a multivariate approach. Highly significant treatment effects were observed, indicating that the 3 tested therapeutic modalities resulted in significant differences in primary outcome variables. Detailed analysis assessing the significance of the tested factors in determining the healing outcomes following each procedure was performed with a stepwise elimination approach of non-significant factors. The results indicated that: (i) the need to create and maintain space should be a key objective of regenerative approaches based upon the principles of guided tissue regeneration; (ii) control of patient's oral hygiene and residual periodontal infection in the oral cavity are strongly associated with clinical outcomes of both regenerative and conventional surgical procedures and should receive proper attention.     

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.     

Bone regeneration in osseous defects using a resorbable nanoparticular hydroxyapatite.

PURPOSE: This animal study examined the de novo bone formation in bony defects following the insertion of autogenous bone alone versus an injectable nanoparticle hydroxyapatite alone and in combination with 25% autogenous bone. The regenerative potentials of the tested materials were compared with each other. MATERIALS AND METHODS: A model with biological similarity to humans with regard to bone regeneration was a prerequisite for the transferability of the results to clinical practice. Therefore, the adult domestic pig was the animal of choice. A total observation period of 6 months was selected. Microradiographic and histologic evaluation of the bone specimens was completed at 8 defined times. RESULTS: Microradiography indicated mineralization rates in the 2 bone substitute groups that were not significantly lower than those found in the autogenous bone group. Histologically, there was suitable osseointegration and osteoconduction of the used material. Complete resorption of the nanoparticle hydroxyapatite had taken place after 12 weeks. CONCLUSIONS: It can be concluded that the evaluated nanoparticular hydroxyapatite met the clinical requirements for a bone substitute material within the limits of this experimental setting. Due to its microstructure, complete resorption took place during the course of this study.     

GTR with bioresorbable membranes in the treatment of intrabony defects: a clinical and histologic study

The aim of the present study was to evaluate clinically and histologically the treatment of intrabony periodontal defects with a bioresorbable membrane barrier. Fifty-two intrabony periodontal defects were treated according to the principles of guided tissue regeneration (GTR) with a bioresorbable membrane. Results were evaluated by assessing probing pocket depth, recession of the gingival margin, and clinical attachment level at baseline and at 1 and 2 years after therapy. Bone level changes were evaluated radiographically. The postoperative phase was uneventful in all cases. There was a mean probing pocket depth reduction from 8.4 to 3.6 mm, a mean increase of gingival margin recession from 1.5 to 3.0 mm, and a mean clinical attachment level change from 9.9 to 6.5 mm. Mean attachment gain was 3.4 mm. Two teeth scheduled for extraction were also treated with the same bioresorbable membrane. The histologic analysis 6 months after treatment revealed the formation of new connective tissue attachment and new alveolar bone in both cases. Based on the histologic findings it can be concluded that the clinical improvements following GTR with this type of bioresorbable membrane may represent, at least in part, true periodontal regeneration.     

Treatment of intrabony defects with guided tissue regeneration and enamel-matrix-proteins. An experimental study in monkeys

BACKGROUND: Enamel matrix proteins (EMD) have recently been introduced in regenerative periodontal treatment. However, no histological data are yet available concerning the effect of treating intrabony periodontal defects with EMD, and no histological comparisons have been made comparing the result of treatment of intrabony defects with EMD with that of the treatment with guided tissue regeneration (GTR). AIM: Therefore, the aim of the present study was to evaluate histologically in monkeys the effect of treating intrabony defects with EMD, GTR or combined EMD and GTR. METHOD: Intrabony periodontal defects were produced surgically at the distal aspect of teeth 14, 11, 21, 24, 34, 31, 41 and 44 in 3 monkeys (Macaca fascicularis). In order to prevent spontaneous healing and to enhance plaque accumulation metal strips were placed into the defects. After 6 weeks the defects were exposed using a full-thickness flap procedure. The granulation tissue was removed and the root surfaces were debrided by means of hand instruments. Subsequently, the defects were treated using one of the following therapies: (i) GTR, (ii) EMD, or (iii) combination of EMD and GTR. The control defects were treated with coronally repositioned flaps. After 5 months, the animals were sacrificed and perfused with 10% buffered formalin for fixation. Specimens containing the defects and surrounding tissues were dissected free, decalcified in EDTA and embedded in paraffin. 8 microm thick histological sections were cut and stained and subsequently examined under the light microscope. RESULTS: In the control specimens, the healing was characterized by a long junctional epithelium and limited periodontal regeneration (i.e., new periodontal ligament, new cementum with inserting connective tissue fibers and new bone) in the bottom of the defect. The GTR-treated defects consistently presented periodontal regeneration when the membranes were not exposed whereas the sites treated only with EMD presented regeneration to a varying extent. The combined therapy did not seem to improve the results. CONCLUSION: It can be concluded that all 3 treatment modalities favor periodontal regeneration.     

Periodontal healing after impacted lower third molar surgery. Precision and accuracy of radiographic assessment of intrabony defects

The effect of periodontal tissues of impacted lower 3rd molar surgery has been investigated in a retrospective study comprising 215 cases, 2 years postoperatively. In order to evaluate the precision and accuracy of the radiographic assessment of intrabony defects on the distal surface of the lower 2nd molar using conventional free hand technique, a methodological study was performed on 25 patients. The error variance due to variability in the radiographic reproduction and examiner inconsistency was between 3 and 4% of the total variance. In order to evaluate the radiographic assessment of intrabony defects, intraoral radiographs were taken in the deepest part of the intrabony defect with and without a probe as an indicator. Comparing the 2 sets of radiographs, the deviation was 1 mm or less in 87.9% of the cases. The radiopaque marker enhanced the accuracy of assessment of intrabony defects to 96.7%. The study shows the intraoral freehand technique to be sufficiently reliable as regards radiographic reproduction of the mandibular molar area. It also demonstrates that the radiographic method describes the depth of postoperative intrabony defects on the distal surface of the lower 2nd molar more accurately than probing depth measurements alone.     

Treatment of intrabony defects with enamel matrix proteins and guided tissue regeneration. A prospective controlled clinical study

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.     

Smoking affects the outcome of guided tissue regeneration with bioresorbable membranes: a retrospective analysis of intrabony defects

OBJECTIVES: To disclose factors that may influence the results of guided tissue regeneration (GTR) treatment in intrabony defects with bioresorbable membranes. METHODS: Forty-seven intrabony defects in 32 patients were treated by means of polylactic acid/citric acid ester copolymer bioresorbable membranes. At baseline and after 1 year, the following parameters were recorded: (1) probing pocket depth (PPD), (2) gingival recession (REC), (3) probing attachment level (PAL)=PPD+REC, (4) presence/absence of plaque (PI), (5) presence/absence of bleeding on probing (BOP) and (6) intrabony component (IC) configuration (i.e. primarily presence of one, two, or three bone walls). Occurrence of membrane exposure and smoking habits were also recorded. Significance of differences between categorical variables was evaluated with McNemar's test, and between numerical variables with the t-test for paired observations. Generalized linear models were constructed to evaluate the influence of various factors on PAL gain and PPD after 1 year, including in the analysis only one defect per patient (i.e. 32 defects) chosen at random. Odds ratios were calculated using the Mantel-Haenszel method. Differences between smokers and non-smokers were evaluated by means of Pearson's chi2 and Student's t-test for non-paired observations. RESULTS: At baseline, a mean PPD of 8.6+/-1.1 mm and a mean PAL of 9.8+/-1.6 mm was recorded. Statistically significant clinical improvements were observed 1 year after GTR treatment. An average residual PPD of 3.7+/-1.1 mm and a mean PAL gain of 3.8+/-1.5 mm were recorded. IC configuration and exposure of the membrane did not seem to influence the results, while a negative effect of smoking on the clinical parameters was observed. Smokers gained approximately 1 mm less in PAL than non-smokers (3.2+/-1.4 versus 4.3+/-1.3, respectively; p=0.03) and had approximately seven times less chances to gain 4 mm in PAL as compared with patients who did not smoke (odds ratio: 0.15). PPD reduction was less pronounced in smokers than in non-smokers (4.5+/-0.7 versus 5.5+/-0.7, respectively; p<0.01), resulting in somewhat deeper residual PPD in smokers than in non-smokers (3.6+/-1.0 versus 3.4+/-1.1; p>0.05). CONCLUSION: Smoking impairs the healing outcome of GTR treatment of intrabony defects with bioresorbable membranes.     

GTR therapy of intrabony defects using 2 different bioresorbable membranes: 12-month results

Abstract. This prospective split-mouth study was designed to compare the clinical and radiographic healing results in intrabony periodontal defects 12 months after GTR therapy with 2 different bioresorbable barriers. The study comprised 25 healthy patients with one pair of contralaterally located intrabony defects with a probing pocket depth of ≥6 mm and radiographic evidence of angular bone loss of ≥4 mm. The 2 defects of each patient were randomized for treatment either with polylactic acid (PLA) membranes or with polyglactin-910 (PG-910) membranes. The patients received systemic doxycycline (100 mg/d) for 11 days post-operatively. One blinded examiner recorded the following clinical parameters using a pressure calibrated probe at baseline and after 12 months: papillary bleeding index (PBI), gingival recession (REC), probing pocket depth (PPD), and probing attachment level (PAL). The vertical relative attachment gain (V-rAG) was calculated as a % of the PAL gain related to the maximum possible attachment gain (expressed by the intrraoperatively measured depth of the osseous defect). Geometrically standardized intraoral radiographs were quantitatively evaluated for bone changes (density, area) in the defect region using digital subtraction radiography (DSR). Clinical and radiographic data were statistically analyzed using the Wilcoxon-signed-rank test (α=0.05). Postoperative membrane exposures occurred in 9 PLA and 13 PG-910 treated sites. After 12 months of healing, both barrier types provided significant PPD reductions and PAL gain [median (25/75 percentile)]: ΔPPD (PLA: 3.0 (2.0/4.0) mm: PG-910: 3.0 (2.0/4.5) mm]; ΔPAL [PLA: 3.0 (2.5/4.0) mm: PG-910: 2.0 (1.0/4.0) mm]. V-rAG amounted to 60% in PLA sites and 54% in PG-910 sites. DSR revealed significant bone density gain after 12 months. 58.3% of she initial defect area in PLA sites and 54.0% of the initial defect area in PG-910 sites showed bone density gain. Neither clinical nor radiographic data revealed any significant difference between the 2 barrier types after 12 months. In conclusion, this 12-month study demonstrated that PLA and PG-910 membranes provided similar favorable regeneration results in deep intrabony periodontal defects.     

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

AIM: Comparison of two bioabsorbable barriers (collagen and polylactic acid (PLA) membranes) combined with a bovine bone mineral (BBM) graft, with an access flap procedure (AFP) alone for treating intrabony defects. MATERIAL AND METHODS: Thirty-four subjects participated in this prospective, controlled clinical trial. Baseline clinical examination (probing depth (PD), clinical attachment level (CAL)) of selected sites was performed 2 months after completion of conservative treatment in conjunction with hard-tissue measurements to ascertain the depth of the defect (cementoenamel junction to the bottom of the defects). After randomly dividing patients into three groups (two membrane groups, one control group), full thickness flaps were elevated and exposed root surfaces planed before filling defects with bone graft and positioning a barrier membrane covering the defect. The control group was treated identically except for the barrier and bone graft placement. Clinical treatment outcomes were finally evaluated 12 months after surgery for changes of PD and CAL. Radiographs at baseline and 12 months were compared using non-standardized digital radiography. RESULTS: A mean reduction in PD value of 5.08 mm and mean CAL gain of 4.39 mm occurred in the collagen-BBM group. Corresponding values for the PLA-BBM group were 4.72 and 3.71 mm, while access flap procedure (AFP) sites produced values of 2.50 and 2.43 mm. All improvements in clinical parameters were statistically significant (p<0.001) within groups for all variables. Both membranes produced statistically greater PD reduction and CAL gain compared with AFP treatment (p<0.05). Comparison between barrier groups failed to reveal any statistically significant difference in probing pocket depth reduction (p=0.56) or in CAL gain (p=0.34). CONCLUSION: Placement of the two barrier membranes used in the present study in combination with BBM graft significantly improved clinical and radiographic parameters of deep intrabony pockets and proved superior to access flap alone.     

Guided tissue regeneration may modulate gene expression in periodontal intrabony defects: a human study

Background and Objective: Guided tissue regeneration has been shown to lead to periodontal regeneration; however, the mechanisms involved remain to be clarified. The present study was carried out to assess the expression of genes involved in the healing process of periodontal tissues in membrane‐protected vs. nonprotected intrabony defects in humans. Material and Methods: Thirty patients with deep intrabony defects (≥ 5 mm, two or three walls) around teeth that were scheduled for extraction were selected and randomly assigned to receive one of the following treatments: flap surgery alone (control group) or flap surgery plus guided tissue regeneration (expanded polytetrafluorethylene (e‐PTFE) membrane) (test group). Twenty‐one days later, the newly formed tissue was harvested and quantitatively assessed using the polymerase chain reaction assay for the expression of the following genes: alkaline phosphatase, receptor activator of nuclear factor‐κB ligand, osteoprotegerin, osteopontin, osteocalcin, bone sialoprotein, basic fibroblast growth factor, interleukin‐1, interleukin4, interleukin‐6, matrix metalloproteinase2 and matrix metalloproteinase9. Results: Data analysis demonstrated that mRNA levels for alkaline phosphatase, receptor activator of nuclear factor‐κB ligand, osteoprotegerin, osteopontin, bone sialoprotein, basic fibroblast growth factor, interleukin‐1, interleukin‐6, matrix metalloproteinase‐2 and matrix metalloproteinase ‐9 were higher in the sites where guided tissue regeneration was applied compared with the control sites (p < 0.05), whereas osteocalcin mRNA levels were lower (p < 0.05). No difference was observed in interleukin‐4 mRNA levels between control and test groups. Conclusion: Within the limits of this study, it can be concluded that genes are differentially expressed in membrane barrier‐led periodontal healing when compared with flap surgery alone, and this may account for the clinical outcome achieved by guided tissue regeneration.     

Effect of pulverized natural bone mineral on regeneration of three-wall intrabony defects. A preclinical study

Aims

The objective of this study is to evaluate the effects of a paste-like bone substitute material with easy handling properties and improved mechanical stability on periodontal regeneration of intrabony defects in dogs.

Materials and methods

Mandibular and maxillary first and third premolars were extracted, and three-wall intrabony defects were created on second and fourth premolars. After a healing period of 3 months, acute type defects were filled with a paste-like formulation of deproteinized bovine bone mineral (DBBM) (particle size, 0.125–0.25 mm) in a collagenous carrier matrix (T1), pulverized DBBM (particle size, 0.125–0.25 mm) without the carrier (T2), or Bio-Oss® granules (particle size, 0.25–1.00 mm) as control (C). All defects were covered with a Bio-Gide® membrane. The dogs were sacrificed after 12 weeks, and the specimens were analyzed histologically and histometrically.

Results

Postoperative healing of all defects was uneventful, and no histological signs of inflammation were observed in the augmented and gingival regions. New cementum, new periodontal ligament, and new bone were observed in all three groups. The mean vertical bone gain was 3.26 mm (T1), 3.60 mm (T2), and 3.81 mm (C). That of new cementum was 2.25 mm (T1), 3.88 mm (T2), and 3.53 mm (C). The differences did not reach statistical significance. The DBBM particles were both incorporated in new bone and embedded in immature bone marrow.

Conclusions

The results of this preclinical study showed that the 0.125–0.25-mm DBBM particles in a powder or paste formulation resulted in periodontal regeneration comparable to the commercially available DBBM. Osteoconductivity, in particular, was not affected by DBBM size or paste formulation.

Clinical relevance

The improved handling properties of the paste-like bone substitute consisting of small DBBM particles embedded in a collagen-based carrier hold promise for clinical applications.     

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.     

Healing following GTR treatment of intrabony defects distal to mandibular 2nd molars using resorbable and non-resorbable barriers

AIMS: The objectives of the present, randomised clinical trial were (i) to evaluate the healing of periodontal intrabony defects at the distal aspect of mandibular 2nd molars using a resorbable polylactic acid (PLA) barrier and a non-resorbable polytetrafluoroethylene (e-PTFE) barrier and (ii) to compare the therapeutic effect of the bioresorbable versus the non-resorbable barrier. METHOD: 19 patients with intrabony defects distal to mandibular 2nd molars > or = 4 mm (on radiographs) were included in the study. The defects all remained 5 years after surgical removal of impacted 3rd molars. Following flap elevation and defect debridement, the defects were randomly covered with, either a resorbable PLA or a non-resorbable e-PTFE barrier. Flaps were repositioned and sutured to completely cover the barriers. Treatment was evaluated clinically after 1 year by measurements of probing depth (PD), probing attachment level (PAL), and probing bone level (PBL) and radiographically by measurements of bone levels on computer digitised images of radiographs taken immediately before and 1 year postsurgery. RESULTS: Both treatments resulted in significant PD reduction, PAL gain, and bone fill. The total PD reduction was 5.3 +/- 1.9 mm for the PLA treated sites and 3.7 +/- 1.7 mm for the e-PTFE treated sites (p<0.05). The corresponding values for PAL gain were 4.7 +/- 0.7 mm and 3.6 +/- 1.7 mm (p<0.05) and for PBL gain 5.1 +/- 1.2 and 3.3 +/- 2.0 mm (p<0.05). Radiographic bone fill averaged 3.4 +/- 1.2 for the PLA and 2.0 +/- 1.6 mm for the e-PTFE barriers (p<0.05). Radiographic bone level measurements were significantly smaller than the corresponding clinical measurements, indicating that radiographs tend to underestimate bone fill. CONCLUSIONS: GTR treatment of deep intrabony defects distal to mandibular second molars using resorbable PLA barriers resulted in significant PD reduction, PAL gain and bone fill at least equivalent to the results obtained using non-resorbable e-PTFE barriers.     

Effect of platelet-rich plasma on the healing of intrabony defects treated with Beta tricalcium phosphate and expanded polytetrafluoroethylene membranes

BACKGROUND: Regenerative periodontal therapy using platelet-rich plasma (PRP) and different types of bone substitutes with or without guided tissue regeneration (GTR) has been proposed as a modality to enhance the outcome of regenerative surgery. However, there are limited data from controlled clinical studies evaluating the effect of PRP on the healing of deep intrabony defects treated with a combination of bone substitutes and GTR. The aim of this study was to clinically evaluate the effect of PRP on the healing of deep intrabony defects treated with beta tricalcium phosphate (beta-TCP) and GTR by means of a non-bioresorbable expanded polytetrafluoroethylene membrane. METHODS: Twenty-eight subjects with advanced chronic periodontal disease and displaying one intrabony defect were treated randomly with a combination of PRP + beta-TCP + GTR or beta-TCP + GTR. Plaque index, gingival index, bleeding on probing, probing depth (PD), gingival recession, and clinical attachment level (CAL) were evaluated at baseline and at 1 year after treatment. CAL was the primary outcome variable. RESULTS: No differences in any of the investigated parameters were observed at baseline between the two groups. Healing was uneventful in all subjects. At 1 year after therapy, the sites treated with PRP + beta-TCP + GTR showed a reduction in mean PD from 9.1 +/- 0.6 mm to 3.3 +/- 0.5 mm (P <0.001) and a change in mean CAL from 10.1 +/- 1.3 mm to 5.7 +/- 1.1 mm (P <0.001). In the group treated with beta-TCP + GTR, mean PD was reduced from 9.0 +/- 0.8 mm to 3.6 +/- 0.9 mm (P <0.001), and the mean CAL changed from 9.9 +/- 1.0 mm to 5.9 +/- 1.2 mm (P <0.001). In both groups, all sites gained > or =3 mm of CAL. CAL gains > or =4 mm were noted in 86% (12 of 14 defects) of the cases treated with PRP + beta-TCP + GTR and in 79% (11 of 14 defects) of those treated with beta-TCP + GTR. No statistically significant differences in any of the investigated parameters were observed between the two groups at the 1-year reevaluation. CONCLUSION: At 1 year after surgery, both therapies resulted in significant PD reductions and CAL gains.