Volumetric Outcomes of Peri-implant Soft Tissue Augmentation with a Xenogeneic Cross-Linked Collagen Scaffold: A Comparative Clinical Study.

Performing soft tissue augmentation (STA) at implant sites to improve esthetics, patient satisfaction, and peri-implant health is common. Several soft tissue grafting materials can be used to increase soft tissue thickness at the second-stage surgery, including human dermal matrices and xenogeneic collagen scaffolds. This study assessed and compared the volumetric outcomes, from second-stage surgery to crown delivery, around implants that received STA with a xenogeneic cross-linked collagen scaffold (XCCS) vs nonaugmented implant sites. Thirty-one patients (31 implant sites) completed the study. Intraoral digital scans were taken at the second stage and prior to crown delivery, and the STL files were imported in an image-analysis software to assess volumetric changes. XCCS-augmented implants showed significantly greater volumetric changes compared to control sites, which showed volume loss. The mean thickness of the XCCS-augmented area was 0.73 mm. There was no difference in patient-reported esthetic evaluations between groups. STA with XCCS provided significantly greater volumetric outcomes compared to nonaugmented sites. Further studies are needed to evaluate the long-term behavior of the augmented peri-implant mucosa and the effects of STA on peri-implant health.

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.

Coronally Advanced Flap with Xenogeneic Collagen Matrix for the Treatment of Gingival Recessions at Sites Presenting with Cervical Restorations or Noncarious Cervical Lesions: A Clinical and Ultrasonographic Study.

The aim of this prospective study was to evaluate the efficacy of a cross-linked xenogeneic volume-stable collagen matrix (CCM) in treating gingival recessions (GRs) at teeth presenting with cervical restorations or noncarious cervical lesions (NCCLs). Fifteen patients with esthetic concerns for multiple sites with GRs and cervical restorations were consecutively enrolled. The sites were treated with a coronally advanced flap (CAF) design in combination with a CCM. When present, the previous restoration was removed, and the cementoenamel junction was reconstructed with a composite material. The CCM was stabilized on the root surface(s) previously occupied by the restoration. The CAF was sutured to completely cover the graft. Clinical measurements and intraoral digital and ultrasonographic scans were collected at baseline and at 3 and 6 months postsurgery. Limited postoperative discomfort was reported by patients during the healing. The mean root coverage at 6 months was 74.81%. Average increases in gingival thickness of 0.43 mm and 0.52 mm were observed when measured with ultrasonography 1.5 mm and 3 mm apical to the gingival margin, respectively (P < .05). Relatively high patient-reported satisfaction and esthetics were associated with the treatment outcomes. The treatment resulted in a significant reduction in dental hypersensitivity (mean: 33 VAS points). The present study demonstrated that CAF + CCM is an effective approach for treating GRs at sites with cervical restorations or NCCLs. Int J Periodontics Restorative Dent 2023;43:147-154. doi: 10.11607/prd.6448.

Coronally advanced flap versus tunnel technique for the treatment of peri-implant soft tissue dehiscences with the connective tissue graft: A randomized, controlled clinical trial.

AIM: To evaluate the efficacy of coronally advanced flap (CAF) versus tunnel technique (TUN) in covering isolated mid-facial peri-implant soft tissue dehiscences (PSTDs). MATERIALS AND METHODS: Twenty-eight participants presenting with isolated non-molar implants exhibiting PSTDs were enrolled and randomized to receive either CAF or TUN, both with a connective tissue graft (CTG). The primary outcome of the study was the percentage of mean PSTD coverage at 12 months. Secondary endpoints included the frequency of complete PSTD coverage, changes in keratinized mucosa width (KMW) and horizontal mucosal thickness (MT), as assessed with transgingival probing, 3D optical scanning and ultrasonography, professional aesthetic evaluation and patient-reported outcome measures (PROMs). RESULTS: At 12 months, the mean PSTD coverage of the CAF and TUN groups was 90.23% and 59.76%, respectively (p = .03). CAF-treated sites showed a substantially higher frequency of complete PSTD coverage (p = .07), together with significantly greater gain of KMW (p = .01), increase in MT (p = .02), volumetric gain (p < .01) and professional aesthetic outcomes (p = .01). Both interventions showed an improvement in patient-reported aesthetics and a reduction of the anxiety related to the appearance of the implant compared to baseline, with the CAF group obtaining significantly higher scores (p = .03 for both PROMs). CONCLUSIONS: CAF + CTG resulted in superior PSTD coverage outcomes, greater gain in KMW and MT, and better PROMs than TUN + CTG for the treatment of isolated PSTDs (ClinicalTrials.gov NCT03498911).

Recombinant human platelet-derived growth factor improves root coverage of a collagen matrix for multiple adjacent gingival recessions: A triple-blinded, randomized, placebo-controlled trial.

AIM: To evaluate the efficacy of recombinant human platelet-derived growth factor (rhPDGF)-BB combined with a cross-linked collagen matrix (CCM) for the treatment of multiple adjacent gingival recession type 1 defects (MAGRs) in combination with the coronally advanced flap (CAF). MATERIALS AND METHODS: Thirty patients were enrolled in this triple-blind, randomized, placebo-controlled trial and treated with either CAF + CCM + rhPDGF, or CAF + CCM + saline. The primary outcome was mean root coverage (mRC) at 6 months. Complete root coverage, gain in gingival thickness (GT), keratinized tissue width, volumetric and ultrasonographic changes, and patient-reported outcome measures were also assessed. Mixed-modelling regression analyses were used for statistical comparisons. RESULTS: At 6 months, the mRC of the CCM + rhPDGF and CCM alone groups were 88.25% and 77.72%, respectively (p = .02). A significant gain in GT was consistently observed for both treatment arms, and more so for the patients receiving the matrix containing rhPDGF through time (0.51 vs. 0.80 mm, on average, p = .01). The rhPDGF + CCM treated patients presented greater volume gain, higher soft tissue thickness, and a superior aesthetic score. CONCLUSION: rhPDGF enhances the clinical, volumetric, and aesthetic outcomes of MAGRs above the results achieved with CAF + CCM alone (ClinicalTrials.gov NCT04462237).

Is the degree of physiological bone remodeling a predictive factor for peri-implantitis?

BACKGROUND: The amount of initial physiological bone remodeling (IPBR) after implant placement varies and the ways it may play a role in peri-implantitis development remains unknown. The aim of this retrospective study was to investigate the association between the amount of IPBR during the first year of implant placement and incidence of peri-implantitis as well as the pattern of progressive bone loss. METHODS: Clinical and radiographic documentation of implants at the time of implant placement (T0), 1 year ± 6 months after crown placement (T1), and at a ≥2-year follow-up from implant placement (T2) were retrospectively collected. IPBR was defined as the bone loss occurring from implant placement to the end of the bone remodeling (T1). Cases were grouped into those diagnosed with (test) or without peri-implantitis (PIm) (control). Linear regression model under generalized estimation equation approach was estimated to assess correlation between marginal bone loss (MBL) rates in both periods (T1-T0) and (T2-T1). Receiver operating characteristics curve was estimated to explore an optimal cut-off point of T1-T0 MBL to discriminate between PIm and no-PIm implants. RESULTS: A total of 45 patients receiving 57 implants without PIm and 40 with PIm were included. There were no associations between PIm and IPBR (p > 0.05), nor between BML of (T2-T1) and (T1-T0). However, arch and total follow-up showed significant influence on the probability of PIm. Splinted implants showed an MBL rate of 0.60-mm/year higher than non-splinted implants (p < 0.001) from T1 to T2. CONCLUSION: No statistically significant association was found between IPBR and incidence of peri-implantitis.

Maintenance visit regularity has a different impact on periodontitis-related tooth loss depending on patient staging and grading.

AIM: To assess whether maintenance variables have a differential effect on tooth loss due to periodontitis (TLP) based on staging and grading. MATERIALS AND METHODS: Patients treated for periodontitis for a minimum of ≥10 years follow-up were included and categorized according to their stage and grade at baseline. Impact of number, regularity, and pattern of supportive periodontal therapy visits (SPT) on TLP was explored by dividing teeth into test (5 year time periods prior to TLP events) and control groups (random 5 year periods without tooth loss). RESULTS: The regularity of maintenance visits, but not the overall quantity, had a significant impact on risk of TLP and showed higher importance as staging and grading increased (larger impact for stages III/IV and grade C). The minimum threshold of visits below which the risk of TLP was equivalent to that of the control group was one visit every 7.4 months for stages I-II, 6.7 months for stage III-IV, 7.2 months for grade B and 6.7 months for grade C. This frequency should be increased for former and current smokers, diabetics and elderly patients. Stage III and IV patients who skip more than 1 year of maintenance in a 5 year period have an increased risk of TLP (OR = 2.55) compared to those only miss 1 year. A similar trend was noted for grade C patients, but not for stages I/II or grades A/B. CONCLUSIONS: Lack of SPT regularity and missing multiple years of maintenance had a larger influence on risk of TLP for higher-level staging and grading.

The correlation between history of periodontitis according to staging and grading and the prevalence/severity of peri-implantitis in patients enrolled in maintenance therapy.

BACKGROUND: The aim of this study was to determine if a previous history of periodontitis according to the preset definitions of the 2017 World Workshop is correlated with increased implant failure, and occurrence and severity of peri-implantitis (PI). METHODS: A retrospective analysis of patients with a history of periodontitis who received nonsurgical and, if indicated, surgical corrective therapy prior to implant placement was performed. Periodontitis stage and grade were determined for each included patient based on data from the time of initiation of active periodontal therapy. Cox Proportional Hazard Frailty models were built to analyze the correlation between stage and grade of periodontitis at baseline with implant failure, as well as occurrence and severity of PI. RESULTS: Ninety-nine patients with a history of periodontitis receiving 221 implants were followed for a mean duration of 10.6 ± 4.5 years after implant placement. Six implants (2.7%) failed and a higher rate of implant failure due to PI was found for Grade C patients (P < 0.05), whereas only an increased trend was seen for Stages III and IV compared with I and II. Grading significantly influenced the risk of marginal bone loss (MBL) >25% of the implant length (P = 0.022) in PI-affected implants. However, a direct correlation between higher-level stage and grade and PI prevalence was not recorded. CONCLUSION: No statistically significant association between periodontitis stage or grade and the prevalence of PI was found. However, when PI was diagnosed, there was a relationship between periodontitis grade and severity of PI or the occurrence of implant failure.

Comparison of epigenetic mediator expression and function in mouse and human embryonic blastomeres.

A map of human embryo development that combines imaging, molecular, genetic and epigenetic data for comparisons to other species and across pathologies would be greatly beneficial for basic science and clinical applications. Here, we compared mRNA and protein expression of key mediators of DNA methylation and histone modifications between mouse and human embryos, embryos from fertile/infertile couples, and following growth factor supplementation. We observed that individual mouse and human embryos are characterized by similarities and distinct differences in DNA methylation and histone modification patterns especially at the single-cell level. In particular, while mouse embryos first exhibited sub-compartmentalization of different histone modifications between blastomeres at the morula stage and cell sub-populations in blastocysts, differential histone modification expression was detected between blastomeres earlier in human embryos at the four- to eight-cell stage. Likewise, differences in epigenetic mediator expression were also observed between embryos from fertile and infertile couples, which were largely equalized in response to growth factor supplementation, suggesting that select growth factors might prevent alterations in epigenetic profiles during prolonged embryo culture. Finally, we determined that reduced expression via morpholino technologies of a single histone-modifying enzyme, Rps6ka4/Msk2, resulted in cleavage-stage arrest as assessed by time-lapse imaging and was associated with aneuploidy generation. Taken together, data document differences in epigenetic patterns between species with implications for fertility and suggest functional roles for individual epigenetic factors during pre-implantation development.