Soft tissue augmentation with a volume-stable collagen matrix or an autogenous connective tissue graft at implant sites: Five-year results of a randomized controlled trial post implant loading

A Novel Pre-Customized Saddle-Shape Soft Tissue Substitute for Volume Augmentation: An Ex Vivo Study in Pig Mandibles

BACKGROUND

Tooth loss results in hard- and soft-tissue volume loss over time. We compared the handling of three different soft tissue substitutes (STS) to the subepithelial connective tissue graft (SCTG) for soft tissue volume augmentation in a pig ex vivo model.

METHODS

Five dentists simultaneously shaped, placed and sutured randomized four graft types in single-tooth soft tissue defects created in pig mandibles. The STS, produced from slightly crosslinked collagen fibres (VCMX), were either 3 mm or 6 mm thick blocks or a newly developed pre-customized saddle-shape. Each graft type was handled 20 times. The time required for shaping, placement, and suturing was recorded. Dentists reported outcomes on the grafts' handling were evaluated with a visual-analogue-scale (VAS). Statistical analysis included calculating means and medians and testing significance.

RESULTS

The mean time of 0.72 min for shaping the pre-customized saddle-shape STS was significantly lower than 1.31 min for SCTG, 1.73 min for 3 mm STS and 2.17 min for 6 mm STS. Placement/suturing time was similar for all grafts. The dentists mainly preferred the saddle-shape STS and the SCTG.

CONCLUSIONS

The saddle-shape STS required less time for graft-shaping and, therefore, reduced the overall treatment time, suggesting a more efficient and less invasive workflow for soft tissue augmentation.

A comparative study of the epithelial regeneration capacities of two biomaterials in vitro

BACKGROUND

Regeneration of periodontal epithelium remains a major focus in current dental research, with various exogenous substitute materials being applied in clinical practice. Yet, the highly organized structure of native tissue still poses considerable challenges for biomaterials attempting to mimic the original environment. In this study, we investigated the effects of a newly developed gelatin/polycaprolactone nanofiber (GPF) and a micro-scaled collagen matrix (CM) on the biological behavior of oral epithelial Ca9-22 cells, aiming to assess the clinical applicability of the materials and conducted a preliminary exploration of the interplay between the Ca9-22 cells and the material properties.

METHODS

The oral epithelial Ca9-22 cell line was cultured onto the GPF, CM, and tissue culture plate (TCP) for 3, 7, and 14 days. Cell morphology, attachment proliferation/viability, the gene expression of keratin 14 (KRT14), keratin 10 (KRT10), integrin β-1 (ITGB-1), intercellular adhesion molecule 1 (ICAM-1), interleukin 8 (IL-8) and interleukin 1β (IL-1β), the levels of IL-8 proteins were evaluated.

RESULTS

Ca9-22 cells exhibited distinct adhesion morphology and distribution patterns on two biomaterials. After 3 days of culturing on GPF, Ca9-22 cells demonstrated higher levels of proliferation/viability compared to those on CM. In most situations, except KRT10, both materials effectively stimulated gene and protein expression related to epithelial regeneration and wound healing, especially in the early stage of culture. Compared to CM, GPF demonstrated a stronger stimulation of KRT14 expression at day 3 and a more significant enhancement of KRT10 expression after 7 and 14 days. However, it was less effective at promoting IL-8 expression after 3 days than the former. The gene expression of KRT10 was suppressed by CM at day 7. The IL-8 protein production was the highest in cells grown on CM.

CONCLUSION

The morphology and cellular functions of oral epithelial cells differed between GPF and CM. Both materials are capable of promoting epithelial regeneration; however, GPF is more conducive to functional stratification of newly formed epithelium, while CM holds a more sustained effect on epithelial proliferation.

Soft-tissue volume augmentation during early, delayed, and late dental implant therapy: A systematic review and meta-analysis on professionally determined esthetics and self-reported patient satisfaction on esthetics

The objective of the study was to assess the effect of soft-tissue volume augmentation during early, delayed, and late dental implant therapy in terms of professionally determined esthetics and self-reported patient satisfaction on esthetics. For this, a comprehensive electronic literature search was performed to identify randomized clinical trials (RCTs) and controlled clinical trials (CCTs) reporting professionally determined esthetic outcomes and self-reported patient satisfaction on esthetics (primary outcomes) during early, delayed, and late dental implant placement comparing soft-tissue volume augmentation to the absence of soft-tissue grafting (control) (PICO 1) or comparing various soft-tissue augmentation techniques, procedures, and materials (PICO 2). Secondary outcomes were mucosal thickness (MT), intra- and postoperative complications, marginal soft-tissue-level changes, keratinized tissue width, radiographic marginal bone levels, and clinical parameters for the diagnosis of peri-implant tissue health. The standard mean differences (SMD)/weighted mean differences (WMD) were estimated for the Pink Esthetic Score (PES), self-reported patient satisfaction assessed by Visual Analog Scale (VAS) and MT gain for PICO 1 and PICO 2 by employing a random effect model. Five RCTs were included for PICO 1, whereas 7 RCTs and 1 CCT addressed PICO 2. PICO 1: The SMD for the PES between autogenous soft-tissue grafting (SCTG) and the absence of grafting (control group) was 0.47; 95% CI [-0.15, 1.09; p = 0.14] based on 5 RCTs. The SMD for the VAS values for patient-reported satisfaction on esthetics in the SCTG and control group was 0.46; 95% CI [-0.12, 1.03; p = 0.12] (2 RCTs). The WMD for gain of MT amounted to 1.06 mm; 95% CI [0.81, 1.31; p = 0.00] in favor of the SCTG group (3 RCTs). PICO 2: The SMD for the PES comparing collagen-based matrices (CM group) to the SCTG group was -0.32; 95% CI: (-0.57, -0.07; p = 0.01), in favor of the SCTG group (5 RCTs and 1 CCT). The SMD for the VAS for patient-reported satisfaction on soft-tissue esthetics was 0.24; 95% CI: (-0.31, 0.78; p = 0.40) (2 RCTs comparing CM vs. SCTG). The WMD for gain of MT was -0.27 mm; 95% CI: (-0.36, -0.17; p = 0.00), significantly favoring the SCTG group (4 RCTs). Professionally and patient-assessed outcomes showed no substantial differences between autogenous soft-tissue grafting and the absence of grafting for early, delayed, and late implant placement. However, autogenous soft-tissue grafts led to significantly improved esthetic outcomes as assessed by professionals compared to soft-tissue substitutes. Patient-assessed outcomes, nevertheless, were similar regardless of the grafting material (i.e., SCTG or soft-tissue substitute). Therefore, autogenous soft-tissue grafting, though, resulted in a considerably higher gain in mucosal thickness compared to both the absence of soft-tissue grafting and the use of soft-tissue substitutes. Complications and adverse events were rarely reported by the included studies, thus suggesting that many trials underreport harms (e.g., complications).

Comparative evaluation of efficacy of volume stable collagen matrix in interdental papilla reconstruction as compared to connective tissue graft in maxillary esthetic region: a randomized controlled clinical trial

OBJECTIVES

The present study compared and evaluated the efficacy of volume-stable collagen matrix (VCMX) and subepithelial connective tissue graft (SCTG) in interdental papilla reconstruction.

MATERIALS AND METHODS

Participants with class II interdental papilla loss (n = 36) were randomly assigned to test (VCMX) and control (SCTG) groups. Papillary height (PH), distance from the contact point to the tip of the papilla (CP-TP), keratinized tissue width (KTW), gingival tissue thickness (GT), and periodontal parameters were assessed at baseline,1, 3, and 6 months. Patient comfort and healing were also evaluated using a visual analog scale (VAS) at 1 week and healing index (HI) at 1,2 and 3 weeks post-operatively.

RESULTS

On intragroup comparison from baseline to 6 months, a statistically significant gain in papillary height, reduction in CP-TP, and an increase in KTW and GT was found in both groups (p = 0.001). Both groups found statistically significant improvement in the healing index from 1 to 3 weeks (p = 0.001). On intergroup comparison, VCMX showed comparable results to SCTG at 6 months, while VAS showed a statistically lower value in VCMX than SCTG (p = 0.044).

CONCLUSIONS

VCMX and SCTG were found to be equally effective in interdental papilla reconstruction in terms of gain in papillary height and reduction in CP-TP distance. VCMX resulted in less post-operative pain compared to SCTG.

CLINICAL RELEVANCE

VCMX may be preferred for interdental papilla reconstruction by clinicians and individuals due to its unlimited availability, which eliminates the need for an additional harvest site and reduces morbidity.

A multi-centre randomized controlled trial comparing connective tissue graft with collagen matrix to increase soft tissue thickness at the buccal aspect of single implants: 3-Year results

AIM

To compare connective tissue graft (CTG) with collagen matrix (CMX) in terms of increase in buccal soft tissue profile (BSP) when applied at single implant sites.

MATERIALS AND METHODS

Patients with a single tooth gap in the anterior maxilla and horizontal mucosa defect were enrolled in a multi-centre randomized controlled trial. All were fully healed sites with a bucco-palatal bone dimension of at least 6 mm, and received an immediately restored single implant using a full digital workflow. Patients were randomly allocated to the control (CTG) or test group (CMX: Geistlich Fibro-Gide, Geistlich Pharma AG, Wolhusen, Switzerland) to increase buccal soft tissue thickness. Primary endpoints were increase in BSP at T1 (immediately postop), T2 (3 months), T3 (1 year) and T4 (3 years) based on superimposed digital surface models. Secondary endpoints included patient-reported, clinical and aesthetic outcomes.

RESULTS

Thirty patients were included per group (control group: 15 males, 15 females, mean age 50.1 years; test group: 14 males, 16 females, mean age 48.2 years) and 50 could be re-examined at T4. The changes in BSP over time were significantly different between the groups (p < .001). At T4, the estimated mean increase in BSP amounted to 0.83 mm (95% confidence interval [CI]: 0.58-1.08) in the control group and 0.48 mm (95% CI: 0.22-0.73) in the test group. The estimated mean difference of 0.35 mm (95% CI: 0.06-0.65) in favour of the control group was significant (p = .021). No significant differences between the groups could be observed in terms of patients' aesthetic satisfaction (p = .563), probing depth (p = .286), plaque (p = .676), bleeding on probing (p = .732), midfacial recession (p = .667), Pink Esthetic Score (p = .366) and Mucosal Scarring Index (p = .438). However, CMX resulted in significantly more marginal bone loss (-0.43 mm; 95% CI: -0.77 to -0.09; p = .015) than CTG.

CONCLUSIONS

CTG was more effective in increasing buccal soft tissue profile and resulted in less marginal bone loss than CMX. Therefore, CTG remains the gold standard to increase soft tissue thickness at implant sites.

CLINICAL TRIAL REGISTRATION

This study was registered in ClinicalTrials.gov (NCT04210596).

Management of Soft Tissue Defects Around Single Implants: A Systematic Review of the Literature

OBJECTIVES

The aim of this systematic review was to assess the effectiveness of the available techniques for the management of peri-implant soft tissue defects around single implants in the anterior region.

MATERIAL AND METHODS

A comprehensive search was conducted in PubMed (MEDLINE), Web of Science (all databases), and Cochrane, using keywords and MeSH terms related to the topic. This systematic review included prospective interventional studies with a minimum of 10 patients and at least 6 months of follow-up.

RESULTS

A total of 13 articles were included, with eight focusing on outcomes related to buccal soft tissue dehiscence coverage procedures and the remaining five investigating interventions aimed at augmenting soft tissue thickness. Coronally advanced flap in combination with connective tissue graft was the most effective technique for buccal soft tissue dehiscence coverage in the medium and long term. In terms of increasing soft tissue thickness, both connective tissue graft and acellular dermal matrix demonstrated satisfactory short-term outcomes; however, their long-term efficacy remains unclear.

CONCLUSIONS

Soft tissue augmentation procedures resulted in satisfactory outcomes, in terms of buccal soft tissue dehiscence coverage and soft tissue thickness increase, around single implants in the esthetic area. Peri-implant plastic surgery has improved both the esthetic appearance and quality of life of patients.

PROSPERO REGISTRATION CODE

CRD42023398424.

Volumetric assessment of volume stable collagen matrix in maxillary single implant site development: A randomized controlled clinical trial

INTRODUCTION

The stability of soft tissue volume around dental implants is an important factor for the final esthetic outcome. The main objective of this study was to compare volume stable collagen matrix (VCMX) versus connective tissue graft (CTG) in the augmentation of soft tissue profiles in single implant sites with a class I Siebert ridge defect.

MATERIALS AND METHODS

Twenty patients (14 females and 6 males) were enrolled in the present study. After implant placement and augmentation of the buccal defect by VCMX or CTG, post-operative evaluation of the volumetric changes at the augmented implant site was carried out at 3, 6, and 9 months as primary outcome, clinical and radiographic soft tissue thickness were carried out at baseline and 9-month intervals, visual analog scale (VAS) and oral health impact profile-14 (OHIP14) were recorded 2 weeks after the surgery.

RESULTS

A statistically significant difference in soft tissue volume was found between baseline and 3, 6, and 9 months postoperatively in both groups with the highest value at 9 months (136.33 ± 86.80) (mm3) in VCMX and (186.38 ± 57.52) (mm3) in CTG. Soft tissue thickness was significantly increased in both groups at 9 months in comparison to baseline. However, there was a significantly higher increase in soft tissue thickness at 9 months in CTG (3.87 ± 0.91) than in VCMX (2.94 ± 0.31). Regarding the radiographic soft tissue thickness, there was a statistically significant increase in both groups at 9 months in comparison to baseline. However, there was a statistically higher increase in the radiographic soft tissue thickness at 9 months in CTG (3.08 ± 0.97) than in VCMX (2.37 ± 0.29). VAS showed a statistically lower value in VCMX (0.4 ± 0.7) than CTG (2.8 ± 1.48). The OHIP recorded lower values in the VCMX group than the CTG group with no statistical significance. In addition, there was no difference in the PES between the two groups.

CONCLUSION

The present study showed that CTG and VCMX were both effective in soft tissue augmentation around implants in the esthetic zone. However, CTG proved more efficient in increasing peri-implant soft tissue volume and mucosal thickness around single implants at a 9-month follow-up period. VCMX was associated with less pain or discomfort and reduced patient morbidity, as reflected by the significantly reduced VAS value in the VCMX group.

Digital three-dimensional assessment of free gingival graft remodeling over 12 months

OBJECTIVE

To digitally evaluate the three-dimensional (3D) remodelling of FGG used to treat RT2 gingival recessions and lack of keratinized tissue on mandibular incisor teeth.

METHODS

Data from 45 patients included in a previous multicentric RCT were analyzed. Silicone impressions were taken before (baseline) and 3, 6 and 12 months after standardized FGG placement. Casts were scanned and images were superimposed, using digital software, to obtain measurements of estimated soft tissue thickness (eTT; 1, 3, and 5 mm apical to baseline gingival margin). In addition, soft tissue volume (STV) and creeping attachment (CA) were assessed.

RESULTS

All patients exhibited postoperative eTT and STV increases, at all time points. The greatest mean thickness gain was observed at eTT3 (1.0 ± 0.4 mm) at 12 months. At 12 months, STV was 52.3 ± 21.1 mm3, without relevant changes compared to the 3- and 6-month follow-up. CA, which was observed as early as six months postoperatively, was evident in ∼85 % of teeth at 12 months.

CONCLUSIONS

Application of FGG was an effective phenotype modification therapy, as shown by the significantly increased tissue thickness postoperatively. Despite the use of FGG technique not aiming for root coverage, digital 3D assessment documented the early and frequent postoperative occurrence of CA, which helped improve recession treatment outcomes.

CLINICAL SIGNIFICANCE

The use of 3D assessment methodology allows precise identification of the tissue gain obtained with FGG, which, regardless of technique, results in predictable phenotype modification and frequent occurrence of creeping attachment.

Efficacy of Xenogeneic Collagen Matrices in Augmenting Peri-Implant Soft Tissue: A Systematic Review and Meta-Analysis

BACKGROUND

Xenogenic collagen matrices (XCMs) are gaining popularity for soft tissue augmentation in dental implants; yet, gaps exist in our understanding of their comparative effectiveness.

OBJECTIVE

This systematic review and meta-analysis focuses on studies that utilize soft tissue augmentation techniques for dental implants to improve keratinized mucosa width (KMW), soft tissue thickness (STT), and soft tissue volume (STV). We compared porcine collagen matrices with autogenous grafts when no bone grafts were utilized.

MATERIALS AND METHODS

We searched databases such as PubMed, Scopus, and the Cochrane Central Register of Controlled Trials for randomized controlled trials and controlled clinical trials published between January 2013 and July 2023 that assessed the efficacy of XCM in peri-implant soft tissue augmentation. The primary outcome included KMW changes while the secondary outcome was STT/STV changes. Statistical analyses were conducted using a random- or fixed-effects model, and heterogeneity was assessed using I2 statistics.

RESULTS

Nine studies were included in the qualitative analysis, and six were included in the meta-analysis. No significant intergroup differences were observed (p > 0.05), but a significant difference was observed in favor of KMW ≥ 2 mm. Heterogeneity among the studies varied at the 6- and 12-month follow-ups, with I2 values of 78% and 0%, respectively. The pooled mean difference between the XCM and autograft groups was -0.96 (-1.71 to -0.21), which shows that there was a larger increase in KMW in the autograft group compared with the XCM group (p < 0.05).

CONCLUSIONS

Collagen matrices are less effective than autogenous grafts at increasing keratinized tissue and STT/STV, but the two techniques yield comparable aesthetic outcomes. Additional studies are necessary to better guide clinical practice and improve patient outcomes.

Effects of implant placement timing and type of soft-tissue grafting on histological and histomorphometric outcomes in a preclinical canine model

AIM

To determine the effects of implant timing and type of soft-tissue grafting on histological and histomorphometric outcomes in a preclinical model.

MATERIALS AND METHODS

Four implant placement protocols were randomly applied at the mesial root sites of the third and fourth mandibular premolars in 10 mongrel dogs: immediate placement (group IP), early placement (group EP), delayed placement with/without alveolar ridge preservation (groups ARP and DP, respectively). A connective-tissue graft (CTG) or porcine-derived volume-stable collagen matrix (VCMX) was applied to enhance the ridge profile (simultaneously with implant placement in group IP and staged for others), resulting in five sites for each combination. All dogs were sacrificed 3 months after soft-tissue grafting. Histological and histomorphometric analyses were performed, and the data were analysed descriptively.

RESULTS

CTG and VCMX were difficult to differentiate from the augmented area. The median total tissue thickness on the buccal aspect of the implant was largest in group IP/CTG (between 2.78 and 3.87 mm). The soft-tissue thickness was generally favourable with CTG at all implant placement timings. Within the DP groups, CTG yielded statistically significantly larger total and soft-tissue thickness than VCMX (p < .05). Among the groups with VCMX, group EP/VCMX showed the largest soft-tissue thickness at apical levels to the implant shoulder.

CONCLUSIONS

CTG generally led to greater tissue thickness than VCMX.

Treatment of class I Sibert alveolar ridge defects with volume stable collagen matrix. A case report

INTRODUCTION AND IMPORTANCE

The soft tissue volume and its stability around dental implants are important for the final aesthetic outcome.

CASE PRESENTATION

A 39-year-old female was referred for dental implant placement for her missing tooth. Following attachment of the cover screw VCMX was used to simultaneously augment buccal ridge defect. Patient was seen 2 weeks after surgery for follow up where sutures were removed. After 3 months, patient received her final crown and been on follow up for 9 months where a successful well-functioning restoration with clinically healthy soft tissue and optimal profilometric outcome were maintained.

CLINICAL DISCUSSION

This approach is relatively simple, less invasive and time saving as it eliminates the need for another surgical donor site to manage the defect.

CONCLUSIONS

The present report showed that VCMX was effective in soft tissue augmentation at implant sites in aesthetic zone.

CLINICAL RELEVANCE

Within the limits of this study, the positive results suggest that the volume stable collagen matrix (VCMX) may be a reliable option in treatment of siebert class I ridge defects. VCMX was associated with less amount of pain or discomfort and reduced patient morbidity.

Autogenous graft versus collagen matrices for peri-implant soft tissue augmentation. A systematic review and network meta-analysis

OBJECTIVE

The primary objective of this review is to compare autogenous soft tissue grafts (connective tissue graft - CTG and free gingival graft-FGG) with different type of matrices (acellular dermal matrix-ADM, xenograft collagen matrix-XCM, volume-stable collagen matrix-VCMX) used to increase peri-implant soft tissues.

MATERIALS AND METHODS

A search on electronic databases was performed to identify randomized and non-randomized controlled trials (RCTs and CCTs, respectively) with either parallel or split-mouth design, and treating ≥ 10 patients. A network meta-analysis (NMA) was used to compare different matrices. Soft tissue thickness dimensional changes and keratinized width (KMW) changes were the primary outcome measures. The secondary outcomes were to evaluate: a) PROMs; b) volumetric changes; c) surgical operating time; and d) different periodontal measurements.

RESULTS

A total of 23 studies were included in the qualitative analysis, and 16 studies (11 RCTs and 5 CCTs) in the quantitative analysis. A total of N = 573 sites were evaluated for NMA. CTG resulted the best material for increasing peri-implant soft tissue thickness, at 180 and 360 days after surgery. The use of an ADM showed good results for buccal thickness increase, primarily in the first three months after surgery. Vestibuloplasty + FGG resulted in the most effective technique for peri-implant KMW augmentation, after 180 days.

CONCLUSIONS

While CTG demonstrated better performance in all the comparison and FGG showed to be the best graft to increase keratinized mucosa up to 90 days, ADM and VCMX may be used to increase soft tissue horizontal thickness with lower patients' morbidity.

LIMITATIONS

The limits of this NMA are the following: a) limited number of included studies; b) high heterogeneity among them (number of patients, treatment sites, surgical techniques, outcome measures, and follow-ups).

CLINICAL RELEVANCE

Many studies compared the efficacy of autogenous and non-autogenous grafts in terms of gingival thickness, volume, and keratinized width increase. However, there is still not clear overall evidence on this topic. This NMA helps clinicians to choose the right material in different peri-implant soft tissue procedures. Recommendations for future studies are mandatory.

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.

The Long-Term Esthetic and Radiographic Outcome of Implants Placed in the Anterior Maxilla after Ridge Preservation, Combining Bovine Xenograft with Collagen Matrix

The objective of the study was to evaluate the long-term esthetic and radiographic results of implants placed in the anterior maxilla after ridge preservation, combining bovine xenograft with collagen matrix. Fifteen patients who required a single tooth extraction because of fracture, root resorption, or extended caries were included in the study. After extraction, all sites were grafted using Deproteinized Bovine Bone Mineral (DBBM) with collagen and covered by a resorbable collagen matrix (CM). Five months after socket grafting, implants were successfully installed. The implant diameter range was between 3.8 and 4.2 mm. All patients were monitored for over 7 years, both clinically and radiographically. Three independent observers evaluated the long-term esthetic outcome, employing the Pink Esthetic Score (PES) technique. Over a period exceeding seven years, a 100% survival rate was observed for all 15 implants, with minimal marginal bone loss. The mean PES was 11.40 (±1.44) at the first assessment and 11.38 (±1.63) at the second assessment. The difference was not statistically significant (p = 0.978), and the scores of PES measurements indicated excellent esthetic results even after seven years. Based on these preliminary results, it seems that placing collagen bovine bone in a fresh extraction socket, covered with a collagen matrix, can preserve the alveolar ridge and provide long-term stable esthetic results.

Soft Tissue Substitutes in Periodontal and Peri-Implant Soft Tissue Augmentation: A Systematic Review

BACKGROUND

Different extracellular matrix (ECM)-based technologies in periodontal and peri-implant soft tissue augmentation have been proposed in the market. The present review compared the efficacy of soft tissue substitutes (STSs) and autogenous free gingival grafts (FGGs) or connective tissue grafts (CTGs) in mucogingival procedures to increase keratinized tissue (KT) width around teeth and implants.

METHODS

Two independent examiners performed an electronic search on MEDLINE and the Cochrane Library based on the following PICOS format: (P) adult patients; (I) soft tissue substitutes and FGGs/CTGs; (C) STSs vs. CTGs; STSs vs. FGGs; STSs vs control; (O) KT width gain; (S) systematic reviews, randomized controlled trials. Studies published before November 2023 were included.

RESULTS

Around teeth, all biomaterials showed superior performance compared to a coronally advanced flap (CAF) alone for treating gingival recessions. However, when compared to CTGs, acellular dermal matrices (ADMs) yield the most similar outcomes to the gold standard (CTGs), even though in multiple recessions, CTGs continue to be considered the most favorable approach. The use of STSs (acellular matrix or tissue-engineered) in combination with apically positioned flaps (APF) resulted in significantly less gain in KT width compared to that achieved with FGGs and APFs. Around dental implants, free gingival grafts were deemed more effective than soft tissue substitutes in enhancing keratinized mucosa width.

CONCLUSIONS

Based on the available evidence, questions remain about the alternative use of soft tissue substitutes for conventional grafting procedures using free gingival grafts or connective tissue grafts around teeth and implants.

Primordial and primary prevention of peri-implant diseases: A systematic review and meta-analysis

AIM

This systematic review and meta-analysis aims to assess the efficacy of risk factor control to prevent the occurrence of peri-implant diseases (PIDs) in adult patients awaiting dental implant rehabilitation (primordial prevention) or in patients with dental implants surrounded by healthy peri-implant tissues (primary prevention).

MATERIALS AND METHODS

A literature search was performed without any time limit on different databases up to August 2022. Interventional and observational studies with at least 6 months of follow-up were considered. The occurrence of peri-implant mucositis and/or peri-implantitis was the primary outcome. Pooled data analyses were performed using random effect models according to the type of risk factor and outcome.

RESULTS

Overall, 48 studies were selected. None assessed the efficacy of primordial preventive interventions for PIDs. Indirect evidence on the primary prevention of PID indicated that diabetic patients with dental implants and good glycaemic control have a significantly lower risk of peri-implantitis (odds ratio [OR] = 0.16; 95% confidence interval [CI]: 0.03-0.96; I² : 0%), and lower marginal bone level (MBL) changes (OR = -0.36 mm; 95% CI: -0.65 to -0.07; I² : 95%) compared to diabetic patients with poor glycaemic control. Patients attending supportive periodontal/peri-implant care (SPC) regularly have a lower risk of overall PIDs (OR = 0.42; 95% CI: 0.24-0.75; I² : 57%) and peri-implantitis compared to irregular attendees. The risk of dental implant failure (OR = 3.76; 95% CI: 1.50-9.45; I² : 0%) appears to be greater under irregular or no SPC than regular SPC. Implants sites with augmented peri-implant keratinized mucosa (PIKM) show lower peri-implant inflammation (SMD = -1.18; 95% CI: -1.85 to -0.51; I² : 69%) and lower MBL changes (MD = -0.25; 95% CI: -0.45 to -0.05; I² : 62%) compared to dental implants with PIKM deficiency. Studies on smoking cessation and oral hygiene behaviors were inconclusive.

CONCLUSIONS

Within the limitations of available evidence, the present findings indicate that in patients with diabetes, glycaemic control should be promoted to avoid peri-implantitis development. The primary prevention of peri-implantitis should involve regular SPC. PIKM augmentation procedures, where a PIKM deficiency exists, may favour the control of peri-implant inflammation and the stability of MBL. Further studies are needed to assess the impact of smoking cessation and oral hygiene behaviours, as well as the implementation of standardized primordial and primary prevention protocols for PIDs.

Design of customized soft tissue substitutes for anterior single-tooth and posterior double-tooth defects: An in vitro study

OBJECTIVE

This study aims to validate the standardized procedure for designing soft tissue substitutes (STS) adapted to optimally fit single-tooth defects in the anterior jaws and double-tooth defects in the posterior jaw and to compare mathematically modeled average shapes.

MATERIALS AND METHODS

Casts from 35 patients with 17 single-tooth defects in anterior region and 21 double-tooth defects in posterior region were scanned. STS were designed and sectioned in 3D slices meshes. Thickness values were documented respecting mesial-distal and buccal-lingual orientations. Graphs were embedded into images, and hierarchical clustering was applied to group STS according to shape and thickness.

RESULTS

STS clustered into two groups per defect type. For anterior single defects, STS (n = 4) were either a small and thin oval: 7 mm buccal-lingual, 4-5 mm mesial-distal direction and 1.1-1.5 mm thick or a larger oval (n = 13): 9 mm buccal-lingual, 5-7 mm mesial-distal and 1.6 m thick. For posterior double tooth defects, STS (n = 10) were either narrow, long and thick: 6-7 mm buccal-lingual, 16-20 mm mesial-distal and 2.2 thick or a wide, thinner rectangle (n = 11): 9-11 mm buccal-lingual, 12-14 mm mesial-distal and 1.1-1.5 mm thick.

CONCLUSIONS

The study validated the standardized digital method to design grafts for soft tissue volume augmentation and identified four average shapes for anterior single-tooth and posterior double-tooth soft tissue defects.

CLINICAL SIGNIFICANCE

We developed and validated a standardized digital method to design an optimal geometrical shape of a soft tissue substitute for oral volume augmentation and combined it with mathematical modeling to identify average shapes for single-interior, and double-posterior tooth defects. The identified average shapes offer the possibility to produce better-fitted xenografts or synthetic STS blocks requiring minimal chair-side adaptation leading to reduced clinical time and patient discomfort and potentially improving soft tissue volume augmentation outcomes.