Autologous Platelet Concentrates in Treatment of Furcation Defects-A Systematic Review and Meta-Analysis

Background: The aim of this review was to evaluate the adjunctive effect of autologous platelet concentrates (APCs) for the treatment of furcation defects, in terms of scientific quality of the clinical trials and regeneration parameters assessment. Methods: A systematic search was carried out in the electronic databases MEDLINE, SCOPUS, CENTRAL (Cochrane Central Register of Controlled Trials), and EMBASE, together with hand searching of relevant journals. Two independent reviewers screened the articles yielded in the initial search and retrieved the full-text version of potentially eligible studies. Relevant data and outcomes were extracted from the included studies. Risk of bias assessment was also carried out. The outcome variables, relative to baseline and post-operative defect characteristics (probing pocket depth (PPD), horizontal and vertical clinical attachment loss (HCAL, VCAL), horizontal and vertical furcation depth (HFD, VFD) were considered for meta-analysis. Results: Ten randomized trials were included in this review. Only one study was judged at high risk of bias, while seven had a low risk, testifying to the good level of the evidence of this review. The meta-analysis showed a favorable effect regarding all outcome variables, for APCs used in adjunct to open flap debridement (p < 0.001). Regarding APCs in adjunct to bone grafting, a significant advantage was found only for HCAL (p < 0.001, mean difference 0.74, 95% CI 0.54, 0.94). The sub-group analysis showed that both platelet-rich fibrin and platelet-rich plasma in adjunct with open flap debridement, yielded significantly favorable results. No meta-analysis was performed for APCs in combination with guided tissue regeneration (GTR) as only one study was found. Conclusion: For the treatment of furcation defects APCs may be beneficial as an adjunct to open flap debridement alone and bone grafting, while limited evidence of an effect of APCs when used in combination with GTR was found.

Extracellular matrix expression and periodontal wound-healing dynamics following guided tissue regeneration therapy in canine furcation defects

AIM

Temporal and spatial expression pattern of extracellular matrix (ECM) components in furcation defects following guided tissue regeneration (GTR) compared with open-flap debridement (OFD).

MATERIAL AND METHODS

In 21 dogs, mandibular second and fourth pre-molars were treated with one non-resorbable and three different resorbable membranes. Third pre-molars were treated by OFD. After 2, 4, 8 weeks and 3, 6, and 12 months, tissues were analysed by immunohistochemistry for collagen I (Col-I) and III (Col-III), fibronectin (FN), bone sialoprotein (BSP), and osteopontin (OPN).

RESULTS

At 2 weeks, the defect was mainly occupied by FN+ granulation tissue (GT), which was sequentially replaced by new connective tissue expressing FN, Col-I, and increasingly Col-III. Following superficial resorptions by OPN+ osteoclasts and odontoclasts, cementum and bone formation ensued with strong expression of BSP and OPN along bone and tooth surfaces. Deposition of Col-I, FN, BSP and OPN+ cementoid and osteoid became evident after 4 weeks. Extrinsic fibres of cementum and bone stained intensely for Col-III. The newly formed periodontal ligament expressed FN, Col-I, and Col-III, but no BSP or OPN.

CONCLUSIONS

The spatial ECM expression was similar for OFD and the different GTR methods, although the timing and quantity of ECM expression were influenced by wound stabilization and inflammatory reactions.

Glycosaminoglycans in gingival crevicular fluid of patients with periodontal class II furcation involvement before and after guided tissue regeneration. A pilot study

BACKGROUND

The levels of glycosaminoglycans in gingival crevicular fluid (GCF) are good indicators of underlying tissue turnover. We hypothesize that connective tissue elements in GCF may be used as indicators of tissue maturation underneath barrier membranes. Therefore, we investigated the levels of sulfated glycosaminoglycans in GCF at sites before and after guided tissue regeneration (GTR).

METHODS

Six patients were selected on the basis of having at least one Class II buccal furcation involvement on a molar tooth. Each molar furcation was treated with the standard GTR surgical protocol using a non-resorbable expanded polytetrafluoroethylene membrane. Gingival crevicular fluid samples were taken at baseline (immediately prior to insertion of the membrane) and at 1, 2, 3, 4, 5, and 6 weeks (immediately prior to removal of the membrane). Glycosaminoglycan levels were determined using an Alcian blue dye detection system.

RESULTS

The mean levels of chondroitin sulfate and total sulfated glycosaminoglycans in GCF significantly decreased during the first 4 weeks after GTR surgery. By week 5, the levels began to rise, and by week 6 the levels had returned to baseline levels.

CONCLUSIONS

Sulfated glycosaminoglycans can be monitored in GCF at healing GTR sites. It is proposed that this is a useful means of monitoring the status of the regenerating tissues. However, further longitudinal studies are required to assess if the sulfated glycosaminoglycans can be used as indicators of tissue maturation under guided tissue membranes used to treat periodontal defects.

Immunohistochemical expression of extracellular matrix components of normal and healing periodontal tissues in the beagle dog

Periodontal regeneration requires formation of periodontal tissues lost due to periodontal disease. To better understand the formation of new periodontal tissues during periodontal repair and regeneration, immunohistochemical expression of extracellular matrix components of normal as well as healing periodontal tissues was evaluated and compared using the avidin-biotin complex immunohistochemical technique. For this purpose, horizontal furcation defects were created around mandibular P2 and P4 of 6 dogs after extraction of P1 and P3. The root surfaces were conditioned with citric acid and expanded polytetrafluoroethylene (ePTFE) membranes were placed and retained 0.5 mm above the cemento-enamel junction. The mucoperiosteal flaps were sutured in a coronal position. Two animals were sacrificed at 2, 4, and 8 weeks, and mesio-distal tissue slices containing normal or healing periodontal tissues were demineralized, dehydrated, and embedded in paraffin. Immunohistochemical localization of type I collagen (CI), fibronectin (FN), secreted protein, acidic and rich in cysteine (SPARC), vitronectin (VN), and bone sialoprotein (BSP) was performed on 6 microns thick sections. Morphological results demonstrated that at 2 weeks after defect creation, lesions were filled primarily with granulation tissue which was gradually replaced by newly-formed fibrous connective tissue, periodontal ligament (PDL), cementum, and bone between 4 and 8 weeks. The results of immunohistochemical study revealed that at 2 weeks the granulation tissue, especially in the intercellular spaces of inflammatory cells, was intensively stained for FN and VN. At 4 and 8 weeks, staining for CI, FN, and VN was found in fibrous connective tissue, the newly-formed PDL, cementum, and osteoid. Further the attachment zone of the PDL collagen fibers to cementum showed intense staining for FN. Immunostaining for SPARC was positive in the new PDL, cementum, and bone, while staining for BSP was restricted to the new cementum and bone. Interestingly, the PDL, especially in areas adjacent to active bone formation, demonstrated intense staining for BSP. However, fibrous connective tissue and PDL proper were unstained for BSP. These results indicate that FN and VN are involved in the early stages of periodontal repair, and periodontal regeneration is achieved through formation of periodontal tissues that are composed of different matrix components specific to different types of periodontal tissues.