PDGF-BB-enriched collagen matrix to treat multiple gingival recessions with the tunneled coronally advanced flap

Autologous platelet concentrates in root coverage procedures

Gingival recessions are vastly prevalent among the general population. With regards to their treatment, recent advancements in periodontal and microsurgical procedures, focusing on minimal invasiveness and patient-centered therapies, have propelled a shift in their contemporary treatment, highlighting the field of biologics and bioactive mediators. Among different classes and types of biologics, autologous platelet concentrates (APCs), also referred to as autologous blood-derived products, are commonly used and preferred among many clinicians. These are essentially obtained via venipuncture (intravenous access) followed by centrifugation, for which numerous protocols and preparation methods have been used, leading to varieties of blood-derived products. In this review, via a systematic search, we explored the efficacy of the different utilized preparation methods and centrifugation protocols of APCs (e.g., platelet-rich plasma (PRP), platelet-rich fibrin (PRF), leucocyte-PRF, advanced-PRF, concentrated growth factor (CGF), etc.) for the treatment of type 1 gingival recessions (RT1, without interproximal attachment loss or noticeable tooth displacement), as well as their effectiveness relative to a common control (treatment with flap advancement alone without any additional material). Based on the available literature from randomized trials found in our systematic search, we observed that utilization of PRF can significantly enhance treatment outcomes when performing a coronally advanced flap, in terms of the amount of root coverage. The improvement in root coverage was further enhanced in the presence of baseline keratinized tissue width, and with an increasing relative magnitude (the more the baseline keratinized tissue width, the better the root coverage outcomes when using PRF). The efficacy of these products needs to be further explored with different graft substitutes and matrices, as well as relative to other commonly applied biologics, through well-conducted and adequately-powered randomized clinical trials.

Treatment of single gingival recessions using biofunctionalized collagen matrix: A case series

BACKGROUND

Connective tissue graft substitutes have been used widely to overcome autogenous graft limitations. Nevertheless, they do not provide comparable results in the treatment of periodontal and peri-implant soft tissue defects. Based on the principles of tissue-engineered materials, injectable platelet-rich fibrin (i-PRF) has been combined with collagen matrices (CMs) to enhance their clinical efficacy. To the best of our knowledge, this is the first case series demonstrating the use of i-PRF for the biofunctionalization of a volume-stable collagen matrix (VCMX) as an adjunct to coronally advanced flap (CAF) to treat single gingival recession (GR) defects.

METHODS & RESULTS

The study included 10 patients. Bleeding on probing, probing depth, GR height, clinical attachment level, esthetics, and dentin hypersensitivity were evaluated. After 6 months, a significant GR reduction (RecRed: 2.15 ± 0.7 mm; p = 0.005) and percentage of root coverage (% RC) of 81.13% were observed. Additionally, 40% of the sites showed complete root coverage. Gingival thickness increased 0.64 mm. Patient-centered evaluations demonstrated dentin hypersensitivity and esthetics improvements by the end of follow-up.

CONCLUSION

VCMX biofunctionalized with i-PRF associated with CAF technique showed promising clinical outcomes in the treatment of single RT1 GR defects.

Risk indicators for gingival recession in the esthetic zone: A cross-sectional clinical, tomographic, and ultrasonographic study

BACKGROUND

To evaluate the risk indicators associated with midfacial gingival recessions (GR) in the natural dentition esthetic regions.

METHODS

Cone-beam computed tomography (CBCT) results of thirty-seven subjects presenting with 268 eligible teeth were included in the cross-sectional study. Clinical measurements included presence/absence of midfacial GR; the depth of the midfacial, mesial, and distal gingival recession; the recession type (RT); keratinized tissue width (KT); and attached gingiva width (AG). Questionnaires were utilized to capture patient-reported esthetics and dental hypersensitivity for each study tooth. Buccal bone dehiscence (cBBD) and buccal bone thickness (cBBT) were measured on the CBCT scans. High-frequency ultrasonography was performed to assess gingival thickness (GT) and buccal bone dehiscence (uBBD). Intraoral optical scanning was obtained to quantify the buccolingual position of each study site (3D profile analysis). Multilevel logistic regression analyses with generalized estimation equations were performed to assess the factors associated with the conditions of interest.

RESULTS

The presence of midfacial GR was significantly associated with the history of periodontal treatment for pocket reduction (OR 7.99, p = 0.006), KT (OR 0.62, p < 0.001), cBBD (OR 2.30, p = 0.015), GT 1.5 mm from the gingival margin (OR 0.18, p = 0.04) and 3D profile 1 mm from the gingival margin (OR 1.04, p = 0.001). The depth of midfacial GR was significantly correlated to previous history of periodontal treatment (OR 0.96, p = 0.001), KT (OR -0.18, p < 0.001), presence of bone fenestration (OR 0.24, p = 0.044), and cBBD (OR 0.43, p < 0.001). The depth of midfacial GR was also the only factor associated with patient-reported esthetics (OR -3.38, p = 0.022), while KT (OR 0.77, p = 0.018) and AG (OR 0.82, p = 0.047) were significantly correlated with patient-reported dental hypersensitivity.

CONCLUSIONS

Several risk indicators of midfacial and interproximal GR in the esthetic region were identified. The use of imaging technologies allowed for detection of parameters associated with the conditions of interest, and, therefore, their incorporation in future clinical studies is advocated. Ultrasonography could be preferred over CBCT for a noninvasive assessment of periodontal phenotype.

Twenty-five years of recombinant human growth factors rhPDGF-BB and rhBMP-2 in oral hard and soft tissue regeneration

Contemporary oral tissue engineering strategies involve recombinant human growth factor approaches to stimulate diverse cellular processes including cell differentiation, migration, recruitment, and proliferation at grafted areas. Recombinant human growth factor applications in oral hard and soft tissue regeneration have been progressively researched over the last 25 years. Growth factor-mediated surgical approaches aim to accelerate healing, tissue reconstruction, and patient recovery. Thus, regenerative approaches involving growth factors such as recombinant human platelet-derived growth factor-BB (rhPDGF-BB) and recombinant human bone morphogenetic proteins (rhBMPs) have shown certain advantages over invasive traditional surgical approaches in severe hard and soft tissue defects. Several clinical studies assessed the outcomes of rhBMP-2 in diverse clinical applications for implant site development and bone augmentation. Current evidence regarding the clinical benefits of rhBMP-2 compared to conventional therapies is inconclusive. Nevertheless, it seems that rhBMP-2 can promote faster wound healing processes and enhance de novo bone formation, which may be particularly favorable in patients with compromised bone healing capacity or limited donor sites. rhPDGF-BB has been extensively applied for periodontal regenerative procedures and for the treatment of gingival recessions, showing consistent and positive outcomes. Nevertheless, current evidence regarding its benefits at implant and edentulous sites is limited. The present review explores and depicts the current applications, outcomes, and evidence-based clinical recommendations of rhPDGF-BB and rhBMPs for oral tissue regeneration.

Living cellular constructs for keratinized tissue augmentation: A 13-year follow-up from a split-mouth randomized, controlled, clinical trial

BACKGROUND

A 13-year follow-up was conducted of a short-term investigation of the use of living cellular construct (LCC) versus free gingival graft (FGG) for keratinized tissue width (KTW) augmentation in natural dentition, to evaluate the long-term outcomes and assess the changes occurring since the end of the original 6-month study.

METHODS

Twenty-four subjects out of the original 29 enrolled participants were available at the 13-year follow-up. The primary endpoint was the number of sites demonstrating stable clinical outcomes from 6 months to 13 years (defined as KTW gain, stability, or ≤0.5 mm of KTW loss, together with reduction, stability, or increase of probing depth, and recession depth [REC] ≤0.5 mm). Secondary outcomes included the assessment of KTW, attached gingiva width (AGW), REC, clinical attachment level, esthetics, and patient-reported outcomes at the 13-year visit, assessing the changes from baseline to 6 months.

RESULTS

Nine sites per group (42.9%) were found to have maintained stable (≤0.5 mm or improved) clinical outcomes from 6 months to 13 years. No significant differences were observed for the clinical parameters between LCC and FGG from 6 months to 13 years. However, the longitudinal mixed model analysis showed that FGG delivered significantly better clinical outcomes over 13 years (p < 0.01). LCC-treated sites exhibited superior esthetic outcomes compared to FGG-treated sites at 6 months and 13 years (p < 0.01). Patient-evaluated esthetics were significantly higher for LCC over FGG (p < 0.01). Patient overall treatment preference was also in favor of LCC (p < 0.01).

CONCLUSIONS

A similar stability of the treatment outcomes from 6 months to 13 years was found for LCC- and FGG-treated sites, with both approaches shown to be effective in augmenting KTW and AGW. However, superior clinical outcomes were found for FGG over 13 years, while LCC was associated with better esthetics and patient-reported outcomes than FGG.

Echo intensity and gray-level co-occurrence matrix analysis of soft tissue grafting biomaterials and dental implants: an in vitro ultrasonographic pilot study

OBJECTIVE

To characterize different allogeneic and xenogeneic soft tissue graft substitutes and to assess their echo intensity and grayscale texture-related outcomes by using high-frequency ultrasonography (HFUS).

METHODS

Ten samples from each of the following biomaterials were scanned using HFUS: bilayered collagen matrix (CM), cross-linked collagen matrix (CCM), multilayered cross-linked collagen matrix (MCCM), human-derived acellular dermal matrix (HADM), porcine-derived acellular dermal matrix (PADM), collagen tape dressing (C) and dental implants (IMPs). The obtained images were then imported in a commercially available software for grayscale analysis. First-order grayscale outcomes included mean echo intensity (EI), standard deviation, skewness, and kurtosis, while second-order grayscale outcomes comprised entropy, contrast, correlation, energy and homogeneity derive from the gray-level co-occurrence matrix analysis. Descriptive statistics were performed for visualization of results, and one-way analysis of variance with Bonferroni post-hoc tests were performed to relative assessments of the biomaterials.

RESULTS

The statistical analysis revealed a statistically significant difference among the groups for EI (p < .001), with the group C showing the lowest EI, and the IMP group presenting with the greatest EI values. All groups showed significantly higher EI when compared with C (p < .001). No significant differences were observed for energy, and correlation, while a statistically significant difference among the groups was found in terms of entropy (p < 0.01), contrast (p < .001) and homogeneity (p < .001). IMP exhibited the highest contrast, that was significantly higher than C, HADM, PADM, CCM and CM.

CONCLUSIONS

HFUS grayscale analysis can be applied to characterize the structure of different biomaterials and holds potential for translation to in-vivo assessment following soft tissue grafting-related procedures.