A Randomized Controlled Trial Comparing Collagen Matrix to Hemostatic Gelatin Sponge as Socket Seal in Alveolar Ridge Preservation.

(1) Objectives: This study aimed to compare a collagen matrix to a hemostatic gelatin sponge as a socket seal in alveolar ridge preservation (ARP). (2) Methods: Systemically healthy patients planned for ARP at two sites with more than 50% of the buccal bone wall remaining after tooth extraction were eligible for inclusion. ARP involved socket grafting using collagen-enriched deproteinized bovine bone mineral. Sites were then randomly assigned to the test group (collagen matrix) or the control group (hemostatic gelatin sponge). The primary outcome was soft tissue thickness in the center of the site at 4 months, analyzed on cone-beam computed tomography. Secondary outcomes included the buccal and lingual soft tissue heights, horizontal bone loss, buccal soft tissue profile changes, wound dimensions, and Socket Wound Healing Score (SWHS). (3) Results: In total, 18 patients (12 females, 6 males) with a mean age of 57.3 years (SD 11.1) were included. Four months after ARP, the soft tissue thickness in the center of the site amounted to 2.48 mm (SD 0.70) in the test group and 1.81 mm (SD 0.69) in the control group. The difference of 0.67 mm (95% CI: 0.20-1.14) in favor of the collagen matrix was statistically significant (p < 0.009). The buccal soft tissue height was also statistically significantly higher for the collagen matrix (0.72 mm; 95% CI: 0.06-1.38; p = 0.034). A trend favoring the collagen matrix was found for the lingual soft tissue height (p = 0.066). No significant differences between the groups in terms of horizontal bone loss, buccal soft tissue profile changes, wound dimensions, and the SWHS were found. (4) Conclusions: The absence of significant differences in hard tissue outcomes suggests that both the collagen matrix and hemostatic gelatin sponge effectively sealed the extraction socket and supported bone preservation. However, the collagen matrix better maintained soft tissue dimensions. The clinical relevance of this finding with respect to the necessity for adjunctive soft tissue augmentation at the time of implant placement is yet to be studied.

A Multi-Centre Randomized Controlled Trial Comparing Connective Tissue Graft with Collagen Matrix to Increase Buccal Soft Tissue Thickness: A Cone-Beam CT Analysis.

(1) Aim: a cross-linked porcine-derived collagen matrix (CMX) has been developed for soft tissue augmentation. Although this grafting material does not require a second surgical site, recent findings have indicated deeper pockets, more marginal bone loss and more midfacial recession in the short term when compared to connective tissue graft (CTG). Hence, the aim of the present study was to evaluate the safety of CMX based on buccal bone loss over a one-year period. (2) Methods: Patients who were missing a single tooth in the anterior maxilla were included, in whom the failing tooth had been removed at least 3 months prior and who presented a horizontal mucosa defect. All sites had a bucco-palatal bone dimension of at least 6 mm as assessed on Cone-Beam Computed Tomography (CBCT) to ensure complete embedding of an implant by bone. All patients received a single implant and an immediate implant restoration using a full digital workflow. Sites were randomly allocated to the control (CTG) or test group (CMX) to increase buccal soft tissue thickness. All surgeries were performed by means of full thickness mucoperiosteal flap elevation, placing CTG and CMX in contact with the buccal bone wall. Safety was assessed by evaluating the impact of CTG and CMX on buccal bone loss over a one-year period using superimposed CBCT scans. (3) Results: thirty patients were included per group (control: 50% females, mean age 50; test: 53% females, mean age 48) and 51 (control: 25; test: 26) could be analyzed for buccal bone loss. At 1 mm apical to the implant-abutment interface (IAI), most horizontal resorption was found pointing to 0.44 mm in the control group and 0.59 mm in the test group. The difference of 0.14 mm (95% CI: -0.17-0.46) was not statistically significant (p = 0.366). At 3 mm and 5 mm apical to the IAI, the difference between the groups was 0.18 mm (95% CI: -0.05-0.40; p = 0.128) and 0.02 mm (95% CI: -0.24-0.28; p = 0.899), respectively. Vertical buccal bone loss amounted to 1.12 mm in the control group and 1.14 mm in the test group. The difference of 0.02 mm (95% CI: -0.53-0.49) was not statistically significant (p = 0.926). (4) Conclusions: In the short term, soft tissue augmentation with CTG or CMX results in limited buccal bone loss. CMX is a safe alternative to CTG. Longer follow-up is needed to assess the impact of soft tissue augmentation on buccal bone.

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: 1-year results.

AIM: To compare connective tissue graft (CTG) with collagen matrix (CMX) in terms of increase in buccal soft tissue profile (BSP) at 1 year 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 sites had a bucco-palatal bone dimension of at least 6 mm, received a single implant and an immediate implant restoration using a full digital workflow. Sites were randomly allocated to the control (CTG) or test group (CMX) to increase buccal soft tissue thickness. The primary outcome was the increase in BSP at 1 year when compared with the pre-operative situation based on superimposed digital surface models. The changes in BSP over time were registered at a buccal area of interest reaching from 0.5 mm below the soft tissue margin to 4 mm more apical. Secondary outcomes included patient-reported, clinical and aesthetic outcomes. RESULTS: Thirty patients were included per group (control: 50% females, mean age 50.1; test: 53% females, mean age 48.2). The increase in BSP at 1 year was 0.98 mm (98.3% confidence interval [CI]: 0.75-1.20) for CTG and 0.57 mm (98.3% CI: 0.34 to 0.79) for CMX. The mean difference of 0.41 mm (98.3% CI: 0.12 to 0.69) in favour of CTG was significant (p < .001). Based on an arbitrarily chosen threshold for success of 0.75 mm increase in BSP, 89.7% of the patients in the control group and 10% of the patients in the test group were successfully treated (odds ratio = 77.90; 95% CI: 13.52 to 448.80; p < .001). Sites treated with CMX demonstrated 0.89 mm (98.3% CI: 0.49 to 1.30) more shrinkage between postop and 1 year than sites treated with CTG. In addition, CMX resulted in significantly more marginal bone loss (0.39 mm; 95% CI: 0.05 to 0.74; p = .026) than CTG. There were no significant differences between the groups in terms of patients' aesthetic satisfaction (p = .938), probing depth (p = .917), plaque (p = .354), bleeding on probing (p = .783), midfacial recession (p = .915), Pink Esthetic Score (p = .121) and Mucosal Scarring Index (p = .965). CONCLUSIONS: CTG remains the gold standard to increase soft tissue thickness at implant sites. Clinicians need to outweigh the benefits of CMX against considerable resorption of the graft. This study was registered in ClinicalTrials.gov (NCT04210596).

Immediate implant placement with or without socket grafting: A systematic review and meta-analysis.

OBJECTIVES: To assess the effect of grafting the gap (SG) between the implant surface and alveolar socket on hard and soft tissue changes following single immediate implant placement (IIP). MATERIALS AND METHODS: Two independent reviewers conducted an electronic literature search in Pubmed, Web of Science, Embase and Cochrane databases as well as a manual search to identify eligible clinical studies up to August 2021. Randomized controlled trials (RCTs) comparing IIP with and without SG were included for a qualitative analysis. Meta-analyses were performed when possible. RESULTS: Out of 3627 records, 15 RCTs were selected and reported on 577 patients who received 604 single immediate implants (IIP + SG: 298 implants in 292 patients; IIP: 306 implants in 285 patients) with a mean follow-up ranging from 4 to 36 months. Two RCTs showed low risk of bias. Meta-analysis revealed 0.59 mm (95% CI [0.41; 0.78], p < 0.001) or 54% less horizontal buccal bone resorption following IIP + SG when compared to IIP alone. In addition, 0.58 mm (95% CI [0.28; 0.88], p < 0.001) less apical migration of the midfacial soft tissue level was found when immediate implants were installed with SG. A trend towards less distal papillary recession was found (MD 0.60 mm, 95% CI [-0.08; 1.28], p = 0.080) when SG was performed, while mesial papillae appeared not significantly affected by SG. Vertical buccal bone changes were also not significantly affected by SG. Insufficient data were available for meta-analyses on horizontal midfacial soft tissue changes, pink esthetic score, marginal bone level changes, probing depth and bleeding on probing. Based on GRADE guidelines, a moderate recommendation for SG following IIP can be made. CONCLUSION: SG may contribute to horizontal bone preservation and soft tissue stability at the midfacial aspect of immediate implants. Therefore, SG should be considered as an adjunct to IIP in clinical practice.

A randomized controlled trial evaluating hyaluronic acid gel as wound healing agent in alveolar ridge preservation.

AIM: To compare the results of administration of hyaluronic acid (HA) gel to no gel administration following alveolar ridge preservation (ARP) in terms of changes in wound dimensions over time. MATERIALS AND METHODS: Systemically healthy patients scheduled for ARP at one or two sites in the incisor, cuspid, or premolar area with at least one neighbouring tooth and >50% buccal bone present following extraction were included. ARP consisted of socket grafting with collagen-enriched, deproteinized bovine bone mineral and socket sealing by means of a collagen matrix. Following surgical therapy, sites were randomly allocated to the control group (no gel application) or the test group (0.8% HA gel applied onto the collagen matrix three times per day for 7 days). Bucco-lingual and mesio-distal wound dimensions were registered at T0 (immediately post operation), T1 (1 week), and T2 (3 weeks). Patient-reported outcomes, clinical outcomes, and hard and soft tissue changes were recorded up to 4 months (T3). RESULTS: In the control group, 20 patients (7 males, 13 females; mean age 53.30) with 23 sites, and in the test group 18 patients (9 males, 9 females; mean age 52.56) with 23 sites, were included. There were no significant differences between the groups in the changes in wound dimensions from T0 to T2 (bucco-lingual aspect: p = .340; mesio-distal aspect: p = .883). Three sites (13%) in the control group and six (26%) in the test group demonstrated complete wound resolution at T2 (p = .259). HA failed to show any effect on the number of analgesics taken (p = .175), patient-reported outcomes (p ≥ .263), alveolitis (p = .136), socket healing (p ≥ .424), soft tissue changes (p ≥ .064), or mucosal scarring (p = .548). However, significantly more horizontal bone loss at the coronal aspect was found in the test group (p ≤ .025). CONCLUSION: HA failed to promote wound resolution on a collagen matrix. This study was registered in ClinicalTrials.gov (NCT04467736).

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-month results.

AIM: To compare connective tissue graft (CTG) with collagen matrix (CMX) in terms of changes over time 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 sites had a bucco-palatal bone dimension of at least 6 mm and received a single implant and immediate implant restoration using a full digital workflow. Sites 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 outcome was increase in BSP at T1 (immediately after operation) and T2 (3 months) based on superimposed digital surface models. Secondary parameters included patient-reported clinical and aesthetic outcomes. RESULTS: Thirty patients were included per group (control: 50% females, mean age 50; test: 53% females, mean age 48). Even though surgeons applied thicker grafts when using CMX, sites treated with CMX demonstrated 0.78 mm (95% CI 0.41-1.14) more shrinkage between T1 and T2 than sites treated with CTG. The final increase in BSP was 1.15 mm (95% CI 0.88-1.43) for CTG and 0.85 mm (95% CI 0.58-1.13) for CMX. The mean difference of 0.30 mm (95% CI -0.01 to 0.61) at T2 in favour of CTG was of borderline significance (p = .054). There were no significant differences between the groups in terms of post-operative bleeding (p = .344), pain (p = .331), number of analgesics taken (p = .504), oedema (p = .227), and pink aesthetic score (p = .655). VAS for post-operative haematoma was 6.56 (95% CI 0.54-12.59) lower for CMX, and surgery time could be reduced by 9.03 min (95% CI 7.04-11.03) when applying CMX. However, CMX resulted in significantly more marginal bone loss (0.38 mm; 95% CI 0.15-0.60), deeper pockets (0.30 mm; 95% CI 0.06-0.54), and more mid-facial recession (0.75 mm; 95% CI 0.39-1.12) than CTG. CONCLUSIONS: CTG remains the gold standard for increasing soft tissue thickness at the buccal aspect of implants.

Soft tissue metric parameters, methods and aesthetic indices in implant dentistry: A critical review.

OBJECTIVES: The primary objective was to provide an overview of soft tissue metric parameters, methods, and aesthetic indices in implant dentistry. The secondary objective was to describe reliability and validity of aesthetic indices. MATERIALS AND METHODS: Two independent reviewers conducted an electronic literature search in Pubmed, Web of Science, Embase, and Cochrane databases up to October 2020 to identify studies on soft tissue metric parameters, methods, and aesthetic indices. Aesthetic indices were evaluated in terms of reliability and validity. Data extraction was performed by the same reviewers. RESULTS: Five metric parameters (papilla height, linear changes in soft tissue level, color assessment, soft tissue thickness, and profilometric soft tissue changes) registered by means of several methods (intra-oral registrations, radiographic assessments, digital analyses, and ultrasonic assessments), and 15 aesthetic indices (Papilla Index (PI), ad hoc questions scored with Visual Analogue Scales, Pink Esthetic Score (PES), Implant Crown Aesthetic Index (ICAI), Implant Aesthetic Score (IAS), Rompen Index, Subjective Esthetic Score, White Esthetic Score, Copenhagen Index, Complex Esthetic Index, Californian Dental Association Index (CDAI), Peri-Implant, and Crown Index, Functional Implant Prosthodontic Score, Implant Restoration Esthetic Index (IREI), and Mucosal Scarring Index (MSI)) could be identified. With respect to metric parameters and methods, intra-oral registrations were least accurate whereas profilometric soft tissue changes on the basis of digital surface models were most accurate. Six aesthetic indices showed good inter-rater reliability (PI, PES, ICAI, CDAI, IREI, and MSI). Good validity could only be shown for two indices (PES and CEI). Given this and on the basis of ease of use and ease of interpretation, PES qualified best for clinical research on single implants. None of the indices fulfilled the quality criteria for clinical research on multiple implants. CONCLUSION: Many soft tissue assessment methods with varying reliability and validity have been described and used, which hampers uniform reporting in implant dentistry. Clinical investigators are advised to measure linear and profilometric soft tissue changes using digital surface models, and to use a reliable and validated aesthetic index. Currently, PES qualifies best for aesthetic evaluation of single implants. An index is to be developed to assess the aesthetic outcome of rehabilitations on multiple implants.

A 3-Year Prospective Study on a Porcine-Derived Acellular Collagen Matrix to Re-Establish Convexity at the Buccal Aspect of Single Implants in the Molar Area: A Volumetric Analysis.

BACKGROUND: Xenogeneic soft tissue substitutes are currently being investigated as an alternative to subepithelial connective tissue grafts (CTG) with the intention to avoid postoperative morbidity associated with autologous grafting. The aim of the present study was to volumetrically evaluate the effectiveness and mid-long-term stability of a porcine-derived collagen matrix (PDCM) (Mucoderm®, Botiss gmbh, Berlin, Germany) in increasing soft tissue volume at the buccal aspect of molar implant sites. METHODS: Periodontally healthy non-smoking patients with a single tooth gap in the molar area were selected for a prospective case series. All sites had a bucco-oral bone dimension of at least 8 mm and demonstrated a horizontal alveolar defect. A wide diameter implant was placed under the elevated buccal flap and a PDCM was applied. The primary outcome was the linear increase in buccal soft tissue profile (BSP) within a well-defined area of interest. This was performed with designated software (SMOP; Swissmeda AG, Zurich, Switzerland) on the basis of superimposed digitalized study casts taken before surgery (T0), immediately after surgery (T1), at three months (T2), one year (T3) and three years (T4). Secondary outcomes were alveolar process deficiency and clinical parameters. RESULTS: Fourteen out of 15 treated patients attended the three-year re-assessment (four females; mean age 51.4 years). Mean linear increase in BSP at T1 was 1.53 mm (p = 0.001). The PDCM showed substantial resorption at T2 (1.02 mm or 66.7%) (p = 0.001). Thereafter, a 0.66 mm volume gain was observed (p = 0.030), possibly due to the installation of a permanent crown displacing the soft tissues to the buccal aspect. This resulted in a linear increase in BSP of 1.17 mm (76.5%) at T4. Alveolar process deficiency significantly reduced over time (p = 0.004). However, 50% of patients still demonstrated a slight (6/14) or obvious (1/14) alveolar process deficiency at study termination. Implants demonstrated healthy clinical conditions. CONCLUSIONS: The PDCM demonstrated marked resorption during the early stages of healing. Due to the matrix thickening the tissues, and the permanent crown displacing the tissues, 76.5% of the initial increase in BSP could be maintained over a three-year period. Half of the patients failed to show perfect soft tissue convexity at the buccal aspect.

A randomized controlled study comparing guided bone regeneration with connective tissue graft to re-establish convexity at the buccal aspect of single implants: A one-year CBCT analysis.

AIM: To compare guided bone regeneration (GBR) with connective tissue graft (CTG) to re-establish convexity at the buccal aspect of single implants. MATERIALS AND METHODS: Patients with a single tooth gap in the anterior maxilla and horizontal alveolar defect were enrolled in a single-blind randomized controlled trial. Sites had to demonstrate buccopalatal bone dimension of at least 6 mm prior to surgery to ensure complete embedding of an implant without the need for bone augmentation. All received a single implant and were randomly allocated to the control group (GBR) or the test group (CTG). Cross-sectional CBCT images at t0 (before surgery), t1 (2 weeks after surgery) and t2 (1 year after surgery) were used to evaluate the buccal soft tissue profile (BSP). Secondary outcome variables were buccal bone thickness (BB), buccal soft tissue thickness (BST), vertical bone loss (VBL) and clinical parameters. RESULTS: Twenty-one patients were included per group (control: 11 females, mean age: 51; test: nine females, mean age: 48). At t2 , a significant increase in BSP between 0.7 and 1.5 mm was observed in each group (p ≤ 0.010). There was no significant difference between the groups at 1 year (p ≥ 0.126). The increase in BSP in the control group was basically the result of BB gain ranging from 0.69 to 1.15 mm. BSP gain in the test group was the result of an increase in BST ranging from 0.67 to 1.38 mm. VBL did not differ significantly between the groups (p ≥ 0.644). Implants demonstrated healthy clinical conditions with no significant differences between the groups for any of the parameters (p ≥ 0.095). CONCLUSION: Within the limitations of superimposed CBCT images, GBR and CTG are effective to re-establish convexity at the buccal aspect of single implants in the short term.