Local application of enamel matrix derivative prevents acute systemic inflammation after periodontal regenerative surgery: A randomized controlled clinical trial

Clinical benefits of autologous platelet concentrate in periodontal intrabony defects: A network meta-analysis of randomized controlled trials

This study aimed to compare clinical benefits of autologous platelet concentrate with other periodontal regenerative approaches in intrabony defects. An electronic and hand search of studies up to December 2022 was conducted. Randomized controlled trials with at least 6 months of follow-up were identified to compare autologous platelet concentrates with enamel matrix derivative, bone graft, guided tissue regeneration, and open-flap debridement. All approaches involved papilla preservation flap surgery. The outcomes included probing depth reduction, clinical attachment level gain, linear bone fill, and safety. A network meta-analysis and meta-regression were performed. Fifty-seven studies were included in five network meta-analyses. Autologous platelets concentrate and its adjunct treatments achieved significantly greater clinical and radiographic parameters than did open-flap debridement, and had comparable or better performance than other regenerative treatments. Platelet-rich fibrin showed superiority over platelet-rich plasma in probing depth reduction at 6-month follow-up. Minimal pain and improved wound healing were observed in the treatments with autologous platelet concentrate. Meta-regression showed that deeper baseline intrabony defects resulted in larger probing depth reductions, while smoking impaired the effectiveness of regenerative surgeries. Minimal invasive flap designs led to less effect of regenerative materials. Autologous platelet concentrate is a promising biomaterial in periodontal regeneration due to its convenience, safety, and biocompatibility characteristics.

Comparison of early wound healing using modified papilla preservation technique between enamel matrix derivative and recombinant human fibroblast growth factor

PURPOSE

Enamel matrix derivative (EMD) has demonstrated beneficial effects on wound healing following surgery. However, the effects of recombinant human fibroblast growth factor 2 (rhFGF-2) in periodontal regeneration therapy have not been extensively studied. This retrospective study was conducted to compare the wound healing outcomes of the modified papilla preservation technique (mPPT) between EMD and rhFGF-2 therapies.

METHODS

A total of 79 sites were evaluated for early wound healing using the modified early wound healing index (mEHI), which included 6 items: incision, fibrin clotting, step, redness, swelling, and dehiscence. A numeric analog scale, along with postoperative images of the 6 mEHI items, was established and used for the evaluations. The inter-rater reliability of the mEHI was assessed via intraclass correlation coefficients (ICCs). After adjusting for factors influencing the mPPT, the differences in mEHI scores between the EMD and rhFGF-2 groups were statistically analyzed. Additionally, radiographic bone fill (RBF) was evaluated 6 months after surgery.

RESULTS

The ICC of the mEHI was 0.575. The mEHI, redness score, and dehiscence scores were significantly higher in the rhFGF-2 group (n=33) than in the EMD group (n=46). Similar results were observed in the subgroup of patients aged 50 years or older, but not in those younger than 50 years. In the subgroup with non-contained bone defects, related results were noted, but not in the subgroup with contained bone defects. However, early wound healing did not correlate with RBF at 6 months after surgery.

CONCLUSIONS

Within the limitations of this study, the findings suggest that early wound healing following the use of mPPT with rhFGF-2 is somewhat superior to that observed after mPPT with EMD. However, mEHI should be improved for use as a predictive tool for early wound healing and to reflect clinical outcomes after surgery.

TGF-β Signalling Mediates the Anti-Inflammatory Activity of Enamel Matrix Derivative In Vitro

Enamel matrix derivative (EMD) prepared from extracted porcine fetal tooth material can support the regrow of periodontal tissues. Previous findings suggest that EMD has anti-inflammatory properties and TGF-β activity in vitro. However, the anti-inflammatory activity of EMD is mediated via TGF-β has not been considered. To this aim, we first established a bioassay to confirm the anti-inflammatory activity of EMD. The bioassay was based on the RAW 264.7 macrophage cell line and proven with primary macrophages where EMD significantly reduced the forced expression of IL-6. We then confirmed the presence of TGF-β1 in EMD by immunoassay and by provoking the Smad2/3 nuclear translocation in RAW 264.7 macrophages. Next, we took advantage of the TGF-β receptor type I kinase-inhibitor SB431542 to block the respective signalling pathway. SB431542 reversed the anti-inflammatory activity of EMD and TGF-β in a bioassay when IL-6 and CXCL2 expression was driven by the LPS stimulation of RAW 264.7 macrophages. This central observation was supported by showing that SB431542 reversed the anti-inflammatory activity of EMD using IL-1β and TNF-α-stimulated ST2 bone marrow stromal cells. Together, these findings implicate that the TGF-β activity mediates at least part of the anti-inflammatory activity of EMD in vitro.

Enamel Matrix Derivative Decreases Pyroptosis-Related Genes in Macrophages

Background: Pyroptosis is a caspase-dependent catabolic process relevant to periodontal disorders for which inflammation is central to the pathophysiology of the disease. Although enamel matrix derivative (EMD) has been applied to support periodontal regeneration, its capacity to modulate the expression of pyroptosis-related genes remains unknown. Considering EMD has anti-inflammatory properties and pyroptosis is linked to the activation of the inflammasome in chronic periodontitis, the question arises whether EMD could reduce pyroptosis signalling. Methods: To answer this question, primary macrophages obtained from murine bone marrow and RAW 264.7 macrophages were primed with EMD before being challenged by lipopolysaccharide (LPS). Cells were then analysed for pyroptosis-signalling components by gene expression analyses, interleukin-1β (IL-1β) immunoassay, and the detection of caspase-1 (CAS1). The release of mitochondrial reactive oxygen species (ROS) was also detected. Results: We report here that EMD, like the inflammasome (NLRP3) and CAS1 specific inhibitors—MCC950 and Ac-YVAD-cmk, respectively—lowered the LPS-induced expression of NLRP3 in primary macrophages (EMD: p = 0.0232; MCC950: p = 0.0426; Ac-YVAD-cmk: p = 0.0317). EMD further reduced the LPS-induced expression of NLRP3 in RAW 264.7 cells (p = 0.0043). There was also a reduction in CAS1 and IL-1β in RAW 264.7 macrophages on the transcriptional level (p = 0.0598; p = 0.0283; respectively), in IL-1β protein release (p = 0.0313), and CAS1 activity. Consistently, EMD, like MCC950 and Ac-YVAD-cmk, diminished the ROS release in activated RAW 264.7 cells. In ST2 murine mesenchymal cells, EMD could not be tested because LPS, saliva, and IL-1β + TNF-α failed to provoke pyroptosis signalling. Conclusion: These findings suggest that EMD is capable of dampening the expression of pyroptosis-related genes in macrophages.

Minimally Invasive Surgical Strategies in Regenerative/Reconstructive Periodontal Therapy

FOCUSED CLINICAL QUESTION

After a quick overview on the original principles of guided periodontal regeneration (GTR), the aim of this paper focuses on the advantages of minimally invasive surgical techniques for periodontal regeneration/reconstruction. The specific clinical question to answer is: Are there new clinical parameters useful to choose the best minimal invasive surgery approach for each periodontal defect? An update of the decision trees is to propose after highlighting some clinical parameters deemed relevant for the choice of the most suitable minimally invasive surgical approach and which therefore are considered by us having a place in the new decision trees.

SUMMARY

Starting from the paper of Evian dated 1985 until that of Aslan in 2017, we have analyzed the minimal periodontal surgical techniques proposed for the periodontal regeneration. In addition to the parameters set in the various flowcharts, we have highlighted the following additional parameters: papilla height loss; supra bone component of the defect; Δ Bone Sounding; width of keratinized tissue.

CONCLUSION

The decision-making chart improved with the new clinically relevant factors may serve as a useful guideline for dentists, but to definitively validate it, further studies need to be developed in the future. In order to clarify the proposed flow chart, the authors present two different clinical cases.

Periodontal regenerative therapy in patients with type 2 diabetes using minimally invasive surgical technique with enamel matrix derivative under 3-year observation: A prospective cohort study

BACKGROUND

Information regarding periodontal regenerative therapy in patients with diabetes mellitus (DM) is limited. This pilot study compared the regenerative outcomes of minimally invasive periodontal surgery using enamel matrix derivative (EMD) between DM and non-DM patients.

METHODS

This prospective study included deep intrabony defects in patients with or without type 2 DM. Minimally invasive surgical technique (MIST) or modified MIST (M-MIST) using EMD, without bone graft materials, was performed. Periodontal examination and intraoral radiography were performed at baseline, 6 months, and 1 and 3 years after surgery.

RESULTS

Ten sites of 10 subjects in the DM group, and 20 sites of 18 subjects in non-DM group were evaluated (mean age; 67.5 ± 7.6 and 63.1 ± 9.7, respectively). Probing depth significantly decreased from 7.1 ± 1.6 and 7.0 ± 1.3 mm to 2.2 ± 0.9 and 2.3 ± 1.1 mm at the 1-year examination in the DM and non-DM groups, respectively. Clinical attachment level (CAL) gain and radiographical defect fill at the 3-year examination were 3.8 ± 1.1 mm and 58.3% ± 10.4%, respectively, in the DM group, and 4.1 ± 1.1 mm and 65.5% ± 18.8%, respectively, in the non-DM group, showing no significant differences between the groups. Multiple regression analysis showed no significant association of CAL gain with DM or age after adjustments for relevant confounders.

CONCLUSIONS

This is the first documented study of successful periodontal tissue regeneration in patients with DM. Minimally invasive surgery combined with EMD yielded significant clinical attachment gain and bone fill in the DM and non-DM groups at comparable levels.

Reconstructive surgical treatment of isolated deep intrabony defects with guided tissue regeneration using entire papilla preservation technique: A prospective case series

BACKGROUND

The aim of this prospective study is to evaluate the clinical applicability of the entire papilla preservation (EPP) technique in the regenerative treatment of isolated deep intrabony defects using native collagen membrane and bone grafting materials.

METHODS

Fifteen healthy and non-smoker patients (nine males and six females; mean age: 47.73 ± 12.18; range 21 to 63 years) with one isolated deep intrabony defect each (baseline probing depth (PD): 9.03 ± 1.62 mm; clinical attachment level (CAL): 11.16 ± 1.81 mm) were treated with guided tissue regeneration. Surgical access to the defect was provided by a single buccal vertical incision with an interdental tunneling flap. Following the granulation tissue removal, intrabony defect was filled with bone substitutes. A collagen barrier was trimmed and placed under the intact defect-associated papilla with palatal positioning suture. Microsurgical sutures were used for primary closure.

RESULTS

At 1 week, healing of the 15 sites was uneventful. During the study, all sites showed 100% primary closure rate. At 1-year follow-up, an average CAL gain of 5.86 ± 1.28 mm (P < 0.0001), PD reduction of 6.1 ± 1.47 mm (P < 0.0001), and minimal increase in gingival recession of 0.23 ± 0.62 mm (P = 0.168) were observed.

CONCLUSION

This novel surgical technique, that keeps the interdental papilla intact, seems promising to provide optimal biomaterial protection and healing conditions, even when a collagen barrier and bone substitutes are applied.