Comparative Evaluation of Bioactive Glass Putty and Platelet Rich Fibrin in the Treatment of Human Periodontal Intrabony Defects: A Randomized Control Trial

Influence of alloplastic materials, biologics, and their combinations, along with defect characteristics, on short-term intrabony defect surgical treatment outcomes: a systematic review and network meta-analysis

BACKGROUND

Treating periodontal intrabony defects remains challenging, alloplast materials and biologics are increasingly utilized to improve regeneration outcomes. However, comparative efficacy on alloplast materials remains limited. This study aimed to evaluate the effectiveness of alloplastic materials, both alone and combined with biologics, in treating periodontal defects.

METHODS

A systematic search of PubMed, Scopus, and CENTRAL identified 74 eligible randomized controlled trials. Meta-analysis assessed data heterogeneity based on defect depth and morphology, classifying defects by wall configuration. Network meta-analysis compared clinical attachment level (CAL) gain, probing depth (PD) reduction, and radiographic linear bone (RLB) gain up to 12 months. Risk of bias was evaluated using the Cochrane Risk of Bias 2 tool, and confidence in network meta-analysis was graded using CINeMA.

RESULTS

Defect depth and morphology significantly impacted heterogeneity outcomes at 6 months, but by 12 months, differences across treatments were less significant. Biphasic calcium phosphate (BCP) and nanocrystalline hydroxyapatite (nHA) showed notable improvements in CAL gain, PD reduction, and RLB gain. Combining nHA with platelet-rich fibrin (PRF) outperformed open flap debridement (mean differences at 6 months for CAL gain: 1.37 mm, PD reduction: 1.52 mm and RLB gain: 1.39 mm). SUCRA ranked bioglass and BCP highest for single treatments, while bioglass with platelet-rich plasma and nHA + PRF excelled among combinations.

CONCLUSIONS

Alloplastic materials, particularly BCP and nHA, significantly enhance periodontal treatment outcomes, especially when combined with biologics like PRF. Defect depth and morphology influence treatment efficacy at 6 months, though by 12 months, treatment outcomes converge, underscoring the value of early, tailored strategies in periodontal therapy.

TRIAL REGISTRATION

Not applicable.

Regeneration of periodontal intrabony defects using platelet-rich fibrin (PRF): a systematic review and network meta-analysis

One of the most promising approaches to correct periodontal bone defects and achieve periodontal regeneration is platelet-rich fibrin (PRF). This systematic review and meta-analysis aimed to evaluate the regeneration of periodontal bone defects using PRF compared to other regenerative treatments. The data search and retrieval process followed the PRISMA guidelines. An electronic search of MEDLINE, Cochrane, and PubMed databases was performed, selecting exclusively randomized clinical trials where the following were measured: probing depth reduction (PD), clinical attachment level gain (CAL), and radiographic bone fill (RBF). Out of 284 selected articles, 32 were chosen based on inclusion criteria. The use of platelet-rich fibrin (PRF) + open flap debridement (OFD), PRF + metformin, PRF + platelet-rich plasma (PRP), and PRF + OFD/bone graft (BG) significantly reduced PD and improved CAL and RBF. However, the combination of PRF + BG, PRF + metformin, and PRF + STATINS reduced CAL. The intervention of PRF combined with different treatments such as metformin, OFD, PRP, BG, and STATINS has a significant impact on improving PD and CAL. The use of PRF significantly improved the regeneration of periodontal bone defects compared to other treatments.

Surgical Management of a Large Endodontic Periapical Lesion With Bone Putty and Platelet-Rich Fibrin: A Case Report With a Two-Year Volumetric Follow-Up

The present case report evaluates the surgical management of a large periapical lesion with palatal perforation using platelet-rich fibrin (PRF) and bone putty material, with a two-year follow-up. A 15-year-old male presented with persistent swelling and pain in the right maxillary anterior region, having a history of trauma and recurrent swelling. Cone beam computed tomography (CBCT) imaging revealed a large periapical lesion extending from teeth #11 to #15 with a palatal breach. Initial non-surgical root canal treatment (RCT) failed due to persistent exudation from teeth #11, #12, and #13. This led to the decision for periradicular surgery involving cystic lesion enucleation, apicoectomy, retrofill with mineral trioxide aggregate (MTA), and placement of bone putty and PRF. Follow-up assessments, including volumetric analysis with ITK-SNAP software (www.itksnap.org), showed a 97% reduction in lesion volume, from 4055 to 132 cubic millimeters. The palatal perforation was successfully repaired, with no clinical symptoms reported. Substantial reduction in lesion size and successful repair of the perforation highlight the potential of this approach in complex surgical endodontic cases.

Fabrication and Characterization of an Innovative Silver- and Gadolinium-Doped Bioglass for Bone Regeneration

Background Periodontal regeneration aims for the three-dimensional reconstruction of bone defects, and over the years, bone grafts with or without barrier membranes have provided us with promising results. Particulate bone grafts can be classified according to the source of procurement as autografts, allografts, xenografts, and alloplasts. Bioglass, an innovative alloplast that uses silica particles as a matrix incorporated with calcium and phosphorus, has been extensively used as a propitious material for bone regeneration owing to its inherent osteogenic ability and biocompatibility but presents with various disadvantages such as slow degradation rate, low mechanical strength, and fracture resistance. A novel silver (Ag)-gadolinium (Gd)-doped bioglass was fabricated to improve the mechanical properties, biocompatibility, and osteogenic ability when compared with bioglass (control). Materials and methods The Ag- and Gd-doped bioglass network was prepared and assessed for the morphological and structural properties by scanning electron microscopy (SEM) analysis, X-ray diffraction (XRD), and attenuated total reflectance (ATR)-infrared (IR). The cytotoxicity of Gd and Ag-doped bioglass was assessed using the MG63 cell line through the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyl tetrazolium bromide) assay at various concentrations and the absorbance of the solution was measured at 570 nm using a microplate reader. The osteogenic ability of the material was assessed by alkaline phosphatase activity and collagen estimation. Results ATR-IR spectroscopy, SEM, and XRD were used to examine the bioglass network doped with Gd and Ag. ATR-IR exhibited classic silicate bands, whereas SEM indicated particles bigger than 5 μm. XRD analysis revealed the production of Na2Ca2Si3O9, Na2Ca4(PO4)2SiO4, and wollastonite. The excellent crystallinity of Na2Ca2Si3O9 provided the bioglass network with good mechanical characteristics. The Gd-Ag-bioglass did not exhibit any toxicity towards the living cells at increasing concentrations from 12.5 µg to 100 µg. The alkaline phosphatase activity was increased by 10% and the collagen estimation remained consistent with bioglass (control). Conclusion In conclusion, the fabrication of the novel Gd-Ag-doped bioglass shows good cytocompatibility and osteogenic ability and shows great potential to enhance bone regeneration.

Clinical Efficacy of Platelet Derivatives in Periodontal Tissue Regeneration: An Umbrella Review

OBJECTIVES

This umbrella review aimed to consolidate the best available evidence regarding the clinical efficacy of platelet derivatives in the treatment of periodontal defects associated with periodontitis and in the management of mucogingival deformities.

MATERIALS AND METHODS

The "umbrella review" strategy was used to identify systematic reviews and meta-analyses. The search was performed without language restrictions and updated at the end of February 2023. The PubMed and Scopus databases, together with gray literature, were included in the search.

RESULTS

The search yielded 412 studies. Subsequently, 12 articles were selected for further examination based on relevance. Finally, eight systematic reviews and meta-analyses were assessed. Regarding intrabony defects, in terms of clinical attachment level (CAL) gain, platelet-rich fibrin (PRF) was observed to lead to a statistically significant attachment gain compared to surgical therapy alone. PRF was also found to show greater CAL gain compared to platelet-rich plasma (PRP) and other biomaterials. The parameter probing depth decreased significantly when PRF was used compared to surgical therapy alone (P < 0.05). Similar results were seen when leukocyte- and platelet-rich fibrin (L-PRF) was applied. In terms of radiographic bone fill, both PRF and PRP showed significantly greater bone fill compared to surgical therapy. Regarding the results of periodontal plastic surgery, PRF favored a slight root coverage compared to the coronally displaced flap. This result depended on the number of PRF and L-PRF membranes used, but Emdogain or connective tissue graft produced better results regardless. However, an improvement in the healing of periodontal tissues was reported.

CONCLUSIONS

Therapies with platelet derivatives applied to intrabony defects provided superior regenerative results compared to monotherapies, except in the case of root coverage.

Injectable platelet-rich fibrin with demineralized freeze-dried bone allograft compared to demineralized freeze-dried bone allograft in intrabony defects of patients with stage-III periodontitis: a randomized controlled clinical trial

Aim

The current randomized controlled clinical trial assessed the effect of injectable platelet-rich fibrin (I-PRF) combined with demineralized freeze-dried bone allograft (DFDBA) compared to DFDBA alone in the management of intrabony defects of stage-III periodontitis patients.

Methodology

Following sample size calculation, twenty stage-III periodontitis patients with ≥ 5 mm clinical attachment level (CAL)-loss and ≥ 3 mm intrabony defects were randomized into test (I-PRF + DFDBA; n = 10) and control (DFDBA; n = 10) groups. CAL (primary outcome), periodontal probing depth (PPD), gingival recession depth (GRD), full-mouth plaque scores (FMPS), full-mouth bleeding scores (FMBS), radiographic linear defect depth (RLDD), and bone fill (secondary outcomes) were examined at baseline, 3, 6, and 9 months post-surgically.

Results

I-PRF + DFDBA and DFDBA independently demonstrated significant intragroup CAL-gain, PPD-, and RLDD-reduction at 3, 6, and 9 months (p < 0.05), with no significant intergroup differences observed (p > 0.05). CAL-gain (mean ± SD) of 2.40 ± 0.70 mm and 2.50 ± 0.85 mm and PPD-reduction of 3.50 ± 1.18 mm and 2.80 ± 0.42 mm were demonstrated for I-PRF + DFDBA and DFDBA at 9 months respectively. Both groups showed significant intragroup RLDD improvement, with a RLDD of 3.58 ± 0.66 mm and 3.89 ± 1.57 mm for I-PRF + DFDBA and DFDBA at 9 months respectively. Stepwise linear regression analysis revealed that baseline RLDD and bone fill at 9 months were significant predictors of CAL (p < 0.05).

Conclusion

Within the present study’s limitations, DFDBA with or without I-PRF resulted in significant improvement in clinical and radiographic periodontal parameters in the surgical treatment of periodontal intrabony defects of stage-III periodontitis patients. Addition of I-PRF to DFDBA does not appear to significantly enhance the DFDBA’s reparative/regenerative outcomes.

Clinical relevance

Within the current study’s limitations, routinely adding I-PRF to DFDBA cannot be recommended to significantly improve DFDBA’s treatment outcomes in intrabony defects.

Network meta-analysis of platelet-rich fibrin in periodontal intrabony defects

OBJECTIVES

To evaluate the effect of platelet-rich fibrin alone or in combination with different biomaterials for the treatment of periodontal intra-bony defect.

METHODS

Up to April 2022, Cochrane library, Medline, EMBASE, and Web of Science databases were searched for randomized clinical trials. The outcomes of interest were probing pocket depth reduction, clinical attachment level gain, bone gain, and bone defect depth reduction. Bayesian network meta-analysis with 95% credible intervals was calculated.

RESULTS

Thirty-eight studies with 1157 participants were included. Platelet-rich fibrin alone or platelet-rich fibrin +biomaterials showed a statistically significant difference when compared with open flap debridement (p < 0.05, low to high certainty evidence). Neither biomaterials alone nor platelet-rich fibrin +biomaterials showed a statistically significant difference when compared to platelet-rich fibrin alone (p > 0.05, very low to high certainty evidence). Platelet-rich fibrin +biomaterials showed insignificant differences as compared to biomaterials alone (p > 0.05, very low to high certainty evidence). Allograft +collagen membrane ranked the best in probing pocket depth reduction while platelet-rich fibrin +hydroxyapatite ranked the best in bone gain.

CONCLUSION

It seems that (1) platelet-rich fibrin with/without biomaterials were more effective than open flap debridement. (2) Platelet-rich fibrin alone provides a comparable effect to biomaterials alone and platelet-rich fibrin +biomaterials. (3) Platelet-rich fibrin +biomaterials provide a comparable effect to biomaterials alone. Although allograft +collagen membrane and platelet-rich fibrin +hydroxyapatite ranked the best in terms of probing pocket depth reduction and bone gain respectively, the difference between different regenerative therapies remains insignificant, and therefore, further studies are still needed to confirm these results.

Clinical efficacy of hyaluronic acid in the treatment of periodontal intrabony defect: a systematic review and meta-analysis

OBJECTIVE

This systematic review aimed to evaluate the effects of hyaluronic acid (HA) alone or in combination with any bone substitute for the treatment of intrabony defects (IBDs).

MATERIAL AND METHODS

Six databases were searched up to April 2022 to find randomized clinical trials comparing the clinical effects of open flap debridement (OFD) + HA versus OFD alone (first group) or OFD + HA + bone substitutes versus OFD + bone substitutes (second group) in the treatment of IBDs with a follow-up of at least 3 months. Random effects models of mean differences were used to determine the clinical attachment level (CAL) gain, probing depth (PD) reduction, and radiographic bone fill (RBF).

RESULTS

Of the 276 studies identified, 6 were included in the qualitative synthesis, and 5 in the meta-analyses. The meta-analyses in the first group showed a statistically significant differences for CAL gain (mean difference [MD]:1.00; 95% confidence interval [CI]:0.65 - 1.35; n = 2) and PD reduction (MD: 0.76; 95%CI: 0.34 - 1.17; n = 2) favoring HA + OFD at 6 months. However, in the second group, the meta-analyses did no show additional effect of HA in association with bone substitute was demonstrated for either CAL gain (MD: 0.57; 95%CI: - 0.30 - 1.43; n = 2) or PD reduction (MD: 1.05; 95%CI: - 0.38 - 2.47; n = 2) but did show significant differences for RBF (MD: 0.57; 95%CI: 0.15 - 0.99; n = 2) at 12 months.

CONCLUSION

Compared with OFD alone, local application of HA in the treatment of IBDs provided a significant CAL gain and PD reduction at 6 months. However, its combination with bone substitutes showed no statistically significant differences at 12 months.

CLINICAL RELEVANCE

The use of OFD + HA improves the CAL and PD in the treatment of IBDs compared to OFD only after 6 months of follow-up. These results are not maintained after 12 months.

Bioactive Glasses in Periodontal Regeneration: Existing Strategies and Future Prospects-A Literature Review

The present review deals with bioactive glasses (BGs), a class of biomaterials renowned for their osteoinductive and osteoconductive capabilities, and thus widely used in tissue engineering, i.e., for the repair and replacement of damaged or missing bone. In particular, the paper deals with applications in periodontal regeneration, with a special focus on in vitro, in vivo and clinical studies. The study reviewed eligible publications, identified on the basis of inclusion/exclusion criteria, over a ranged time of fifteen years (from 1 January 2006 to 31 March 2021). While there are many papers dealing with in vitro tests, only a few have reported in vivo (in animal) research, or even clinical trials. Regardless, BGs seem to be an adequate choice as grafts in periodontal regeneration.

The Adjunctive Use of Leucocyte- and Platelet-Rich Fibrin in Periodontal Endosseous and Furcation Defects: A Systematic Review and Meta-Analysis

The aim of this systematic review of randomized controlled trials was to evaluate the adjunctive use of leucocyte- and platelet-rich fibrin (L-PRF) in periodontal endosseous and furcation defects, as compared without L-PRF. The endosseous defect group was subclassified into: L-PRF/open flap debridement (L-PRF/OFD) versus OFD, L-PRF/osseous graft (L-PRF/OG) versus OG, L-PRF/Emdogain (L-PRF/EMD) versus EMD, and L-PRF/guided tissue regeneration (L-PRF/GTR) versus GTR. The furcation defect group was subclassified into L-PRF/OFD versus OFD, and L-PRF/OG versus OG. Mean difference, 95% confidence intervals and forest plots were calculated for probing pocket depth (PPD), clinical attachment level (CAL) and radiographic defect depth (DD). Nineteen studies concerning systemically healthy non-smokers were included. The results of this systematic review and meta-analysis showed in two- and/or three-wall endosseous defects that the adjunctive use of L-PRF to OFD or OG was significantly beneficial for PPD reduction, CAL gain and DD reduction, as compared without L-PRF. Furthermore, the data showed that for two- and/or three-wall endosseous defects, the adjunctive use of L-PRF to GTR was significantly beneficial for CAL and DD improvement, whereas adding L-PRF to EMD had no significant effect, and that for class II furcation defects, the addition of L-PRF to OFD was significantly beneficial for PPD, CAL and DD improvement, whereas the addition of L-PRF to OG was significantly clinically beneficial. In conclusion, this systematic review and meta-analysis found that there was significant clinical and radiographic additive effectiveness of L-PRF to OFD and to OG in two- and/or three-wall periodontal endosseous defects of systemically healthy non-smokers, as compared without L-PRF.

Use of platelet-rich fibrin for the treatment of periodontal intrabony defects: a systematic review and meta-analysis

Objectives

This study aims to compare the treatment outcomes of periodontal intrabony defects by using platelet-rich fibrin (PRF) with other commonly utilized modalities.

Materials and methods

The eligibility criteria comprised randomized controlled trials (RCTs) comparing the clinical outcomes of PRF with that of other modalities. Studies were classified into 10 categories as follows: (1) open flap debridement (OFD) alone versus OFD/PRF; (2) OFD/bone graft (OFD/BG) versus OFD/PRF; (3) OFD/BG versus OFD/BG/PRF; (4–6) OFD/barrier membrane (BM), OFD/PRP, or OFD/enamel matrix derivative (EMD) versus OFD/PRF; (7) OFD/EMD versus OFD/EMD/PRF; (8–10) OFD/PRF versus OFD/PRF/metformin, OFD/PRF/bisphosphonates, or OFD/PRF/statins. Weighted means and forest plots were calculated for probing depth (PD), clinical attachment level (CAL), and radiographic bone fill (RBF).

Results

From 551 articles identified, 27 RCTs were included. The use of OFD/PRF statistically significantly reduced PD and improved CAL and RBF when compared to OFD. No clinically significant differences were reported when OFD/BG was compared to OFD/PRF. The addition of PRF to OFD/BG led to significant improvements in CAL and RBF. No differences were reported between any of the following groups (OFD/BM, OFD/PRP, and OFD/EMD) when compared to OFD/PRF. No improvements were also reported when PRF was added to OFD/EMD. The addition of all three of the following biomolecules (metformin, bisphosphonates, and statins) to OFD/PRF led to statistically significant improvements of PD, CAL, and RBF.

Conclusions

The use of PRF significantly improved clinical outcomes in intrabony defects when compared to OFD alone with similar levels being observed between OFD/BG and OFD/PRF. Future research geared toward better understanding potential ways to enhance the regenerative properties of PRF with various small biomolecules may prove valuable for future clinical applications. Future research investigating PRF at histological level is also needed.

Clinical relevance

The use of PRF in conjunction with OFD statistically significantly improved PD, CAL, and RBF values, yielding to comparable outcomes to OFD/BG. The combination of PRF with bone grafts or small biomolecules may offer certain clinical advantages, thus warranting further investigations.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00784-021-03825-8.

Platelet-Rich Fibrin as a Bone Graft Material in Oral and Maxillofacial Bone Regeneration: Classification and Summary for Better Application

Platelet-rich fibrin (PRF) is an autologous platelet concentrate that consists of cytokines, platelets, leukocytes, and circulating stem cells. It has been considered to be effective in bone regeneration and is mainly used for oral and maxillofacial bone. Although currently the use of PRF is thought to support alveolar ridge preservation, there is a lack of evidence regarding the application of PRF in osteogenesis. In this paper, we will provide examples of PRF application, and we will also summarize different measures to improve the properties of PRF for achieving better osteogenesis. The effect of PRF as a bone graft material on osteogenesis based on laboratory investigations, animal tests, and clinical evaluations is first reviewed here. In vitro, PRF was able to stimulate cell proliferation, differentiation, migration, mineralization, and osteogenesis-related gene expression. Preclinical and clinical trials suggested that PRF alone may have a limited effect. To enlighten researchers, modified PRF graft materials are further reviewed, including PRF combined with other bone graft materials, PRF combined with drugs, and a new-type PRF. Finally, we will summarize the common shortcomings in the application of PRF that probably lead to application failure. Future scientists should avoid or solve these problems to achieve better regeneration.

The Combined Effect of Bioactive Glass and Platelet-Rich Fibrin in Treating Human Periodontal Intrabony Defects - A Clinicoradiographic Study

Background:

Platelets are richest source for cytokine and growth factors which are two important components for the re-establishment of bone and maturation of the soft tissue.

Aims and Objective:

The additive effect of PRF along with a synthetic bone graft material in treating human intrabony periodontal defects has been evaluated in this study. The appropriate use of platelet-rich fibrin (PRF) as an alternate comfortable graft material to restore the lost periodontal tissues has been well documented and has given clinically promising outcome.

Materials and Method:

Platelet-rich fibrin (PRF) is prepared from patient's own blood which is autologous in nature. Perio Glas (PG) is an easy to use synthetic absorbable osteostimulative as well as osteoconductive bone graft material. The selected 30 sites were randomly divided into two groups such as Test (15 sites using PRF) and Control (15 sites without PRF).

Results:

At the end of Six months, the post-operative evaluations revealed significant reduction in PPD and gain in CAL. Radiographic evidence of bone formation was also noticed. The incorporation of PRF with synthetic bone graft (perioglas) produces effective and rapid periodontal regeneration with improved healing in intrabony osseous defects. The PRF group showed a mean Radiographic Defect Fill (RDL) of 1.24 ± 0.04 compared with 0.79 ± 0.07 of control group which is statistically significant.

Conclusion:

This combination technique can be used as an alternate grafting modality for the treatment of intrabony periodontal defects with satisfactory clinical consequences.

Combined endodontic therapy and peri-radicular regenerative surgery in the treatment of dens invaginatus type III associated with apicomarginal defect

Dens invaginatus (DI) is a dental developmental abnormality, probably resulting from an infolding of the dental papilla during tooth development. The following case report presents a case of Type III DI with apicomarginal defect and peri-radicular lesion, diagnosed with cone-beam computed tomography scan and treated with combined orthograde endodontic therapy and peri-radicular regenerative surgery. Follow-up examination at 2 years revealed uneventful healing and improvement in the status of the tooth-supporting structures.

Autologous platelet concentrates for treating periodontal infrabony defects

BACKGROUND

Periodontal disease is a condition affecting tooth-supporting tissues (gingiva, alveolar bone, periodontal ligament, and cementum), with the potential of introducing severe adverse effects on oral health. It has a complex pathogenesis which involves the combination of specific micro-organisms and a predisposing host response. Infrabony defects are one of the morphological types of alveolar bone defects that can be observed during periodontitis. Recent approaches for the treatment of infrabony defects, combine advanced surgical techniques with platelet-derived growth factors. These are naturally synthesized polypeptides, acting as mediators for various cellular activities during wound healing. It is believed that the adjunctive use of autologous platelet concentrates to periodontal surgical procedures produces a better and more predictable outcome for the treatment of infrabony defects.

OBJECTIVES

To assess the effects of autologous platelet concentrates (APC) used as an adjunct to periodontal surgical therapies (open flap debridement (OFD), OFD combined with bone grafting (BG), guided tissue regeneration (GTR), OFD combined with enamel matrix derivative (EMD)) for the treatment of infrabony defects.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 27 February 2018); the Cochrane Central Register of Controlled Trials (CENTRAL; 2018, Issue 1) in the Cochrane Library (searched 27 February 2018); MEDLINE Ovid (1946 to 27 February 2018); Embase Ovid (1980 to 27 February 2018); and LILACS BIREME Virtual Health Library (from 1982 to 27 February 2018). The US National Institutes of Health Ongoing Trials Register (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials on 27 February 2018. No restrictions were placed on the language or date of publication when searching the electronic databases.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of both parallel and split-mouth design, involving patients with infrabony defects requiring surgical treatment. Studies had to compare treatment outcomes of a specific surgical technique combined with APC, with the same technique when used alone.

DATA COLLECTION AND ANALYSIS

Two review authors independently conducted data extraction and risk of bias assessment, and analysed data following Cochrane methods. The primary outcomes assessed were: change in probing pocket depth (PD), change in clinical attachment level (CAL), and change in radiographic bone defect filling (RBF). We organised all data in four groups, each comparing a specific surgical technique when applied with the adjunct of APC or alone: 1. APC + OFD versus OFD, 2. APC + OFD + BG versus OFD + BG, 3. APC + GTR versus GTR, and 4. APC + EMD versus EMD.

MAIN RESULTS

We included 38 RCTs. Twenty-two had a split-mouth design, and 16 had a parallel design. The overall evaluated data included 1402 defects. Two studies were at unclear overall risk of bias, while the remaining 36 studies had a high overall risk of bias.1. APC + OFD versus OFD alone Twelve studies were included in this comparison, with a total of 510 infrabony defects. There is evidence of an advantage in using APC globally from split-mouth and parallel studies for all three primary outcomes: PD (mean difference (MD) 1.29 mm, 95% confidence interval (CI) 1.00 to 1.58 mm; P < 0.001; 12 studies; 510 defects; very low-quality evidence); CAL (MD 1.47 mm, 95% CI 1.11 to 1.82 mm; P < 0.001; 12 studies; 510 defects; very low-quality evidence); and RBF (MD 34.26%, 95% CI 30.07% to 38.46%; P < 0.001; 9 studies; 401 defects; very low-quality evidence).2. APC + OFD + BG versus OFD + BG Seventeen studies were included in this comparison, with a total of 569 infrabony defects. Considering all follow-ups, as well as 3 to 6 months and 9 to 12 months, there is evidence of an advantage in using APC from both split-mouth and parallel studies for all three primary outcomes: PD (MD 0.54 mm, 95% CI 0.33 to 0.75 mm; P < 0.001; 17 studies; 569 defects; very low-quality evidence); CAL (MD 0.72 mm, 95% CI 0.43 to 1.00 mm; P < 0.001; 17 studies; 569 defects; very low-quality evidence); and RBF (MD 8.10%, 95% CI 5.26% to 10.94%; P < 0.001; 11 studies; 420 defects; very low-quality evidence).3. APC + GTR versus GTR alone Seven studies were included in this comparison, with a total of 248 infrabony defects. Considering all follow-ups, there is probably a benefit for APC for both PD (MD 0.92 mm, 95% CI -0.02 to 1.86 mm; P = 0.05; very low-quality evidence) and CAL (MD 0.42 mm, 95% CI -0.02 to 0.86 mm; P = 0.06; very low-quality evidence). However, given the wide confidence intervals, there might be a possibility of a slight benefit for the control. When considering a 3 to 6 months and a 9 to 12 months follow-up there were no benefits evidenced, except for CAL at 3 to 6 months (MD 0.54 mm, 95% CI 0.18 to 0.89 mm; P = 0.003; 3 studies; 134 defects). No RBF data were available.4. APC + EMD versus EMDTwo studies were included in this comparison, with a total of 75 infrabony defects. There is insufficient evidence of an overall advantage of using APC for all three primary outcomes: PD (MD 0.13 mm, 95% CI -0.05 to 0.30 mm; P = 0.16; 2 studies; 75 defects; very low-quality evidence), CAL (MD 0.10 mm, 95% CI -0.13 to 0.32 mm; P = 0.40; 2 studies; 75 defects; very low-quality evidence), and RBF (MD -0.60%, 95% CI -6.21% to 5.01%; P = 0.83; 1 study; 49 defects; very low-quality evidence).All studies in all groups reported a survival rate of 100% for the treated teeth. No complete pocket closure was reported. No quantitative analysis regarding patients' quality of life was possible.

AUTHORS' CONCLUSIONS

There is very low-quality evidence that the adjunct of APC to OFD or OFD + BG when treating infrabony defects may improve probing pocket depth, clinical attachment level, and radiographic bone defect filling. For GTR or EMD, insufficient evidence of an advantage in using APC was observed.