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).

A multi-centre randomized controlled trial on alveolar ridge preservation with immediate or delayed implant placement: Need for soft-tissue augmentation.

AIM: To assess the impact of the timing of implant placement following alveolar ridge preservation (ARP) on the need for soft-tissue augmentation (STA) and to identify the risk factors for horizontal and vertical soft-tissue loss. MATERIALS AND METHODS: Patients with a single failing tooth in the anterior maxilla (15-25) were treated at six centres. Following tooth extraction, they were randomly allocated to the test group (immediate implant placement, IIP) or control group (delayed implant placement, DIP). ARP was performed in both groups and implants were immediately restored with an implant-supported provisional crown. Six months after tooth extraction and ARP, a panel of five blinded clinicians assessed the need for STA on the basis of anonymized clinical pictures and a digital surface model. Lack of buccal soft-tissue convexity and/or mid-facial recession qualified for STA. Pre-operative and 6-month digital surface models were superimposed to assess horizontal and vertical soft-tissue changes. RESULTS: Thirty patients were included per group (test: 20 females, 10 males, mean age 53.1; control: 15 females, 15 males, mean age 59.8). The panel deemed STA as necessary in 24.1% and 35.7% of the cases following IIP and DIP, respectively. The difference was not statistically significant (odds ratio [OR] = 1.77; 95% confidence interval [CI] [0.54-5.84]; p = .343). Loss of buccal soft-tissue profile was higher following DIP (estimated mean ratio = 1.66; 95% CI [1.10-2.52]; p = .018), as was mid-facial recession (mean difference [MD] = 0.47 mm; 95% CI [0.12-0.83]; p = .011). Besides DIP, regression analysis identified soft-tissue thickness (-0.57; 95% CI [-1.14 to -0.01]; p = .045) and buccal bone dehiscence (0.17; 95% CI [0.01-0.34]; p = .045) as additional risk factors for mid-facial recession. Surgeons found IIP significantly more difficult than DIP (visual analogue scale MD = -34.57; 95% CI [-48.79 to -20.36]; p < .001). CONCLUSIONS: This multi-centre randomized controlled trial failed to demonstrate a significant difference in the need for STA between IIP and DIP when judged by a panel of blinded clinicians. Based on objective soft-tissue changes, patients with thin buccal soft tissues, with a buccal bone dehiscence and treated with a delayed approach appeared particularly prone to soft-tissue loss.

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).

A randomized controlled trial comparing guided bone regeneration to connective tissue graft to re-establish buccal convexity at dental implant sites: Three-year results.

OBJECTIVES: To compare guided bone regeneration (GBR) to connective tissue graft (CTG) in terms of increase in buccal soft tissue profile (BSP) at three-year follow-up when applied at the buccal aspect of single implant sites demonstrating a minor horizontal alveolar defect. MATERIALS AND METHODS: Patients with a single tooth gap in the anterior maxilla and horizontal alveolar defect were enrolled in a single-blind RCT. All sites had a bucco-palatal bone dimension of at least 6 mm, received a single implant at least 3 months after tooth removal and were randomly allocated to the control (GBR) or test group (CTG) to re-establish buccal soft tissue convexity. Primary outcome was linear increase in BSP, meaning increase at the buccal aspect of the implant, based on superimposed digital surface models. Secondary outcomes were buccal bone and buccal soft tissue thickness, aesthetic and clinical parameters. RESULTS: Twenty-one patients were included per group at baseline. After three years, three patients in the GBR group and four in the CTG group were not willing to return for re-assessment. Hence, the final sample included 9 females/9 males (mean age 52) in the GBR group and 8 females / 9 males in the CTG group (mean age 49). The changes in BSP over time were not significantly different between GBR and CTG (p = 0.629). At three years, sites treated with GBR demonstrated 1.06 mm (95% CI: 0.83; 1.28) increase in BSP, whereas sites treated with CTG showed 0.99 mm (95% CI: 0.65; 1.35) increase in BSP (p = 0.699) compared to baseline. There were no significant differences between the groups for any of the parameters except for Mucosal Scarring Index, which was 1.63 (95% CI: 0.73; 2.53) lower for CTG (p = 0.002) at study termination. CONCLUSION: There was no significant difference in linear increase in BSP between GBR and CTG after three years. Hence, clinical decision-making should be based on other factors.

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.

A randomized controlled study comparing guided bone regeneration with connective tissue graft to re-establish buccal convexity: One-year aesthetic and patient-reported outcomes.

OBJECTIVES: To compare guided bone regeneration (GBR) with connective tissue graft (CTG) in terms of aesthetic and patient-reported outcomes (PROMs). MATERIALS AND METHODS: Patients with a single tooth gap in the anterior maxilla and horizontal alveolar defect were enrolled in a single-blind RCT. All sites had a buccopalatal bone dimension of at least 6 mm, received a single implant and were randomly allocated to the control (GBR) or test group (CTG) to re-establish buccal soft tissue convexity. Primary outcomes were Pink Esthetic Score (PES) and Mucosal Scarring Index (MSI) assessed after 1 year. Secondary outcomes included PROMs registered during the early stages of healing and after 1 year. RESULTS: Twenty-one patients were included per group (control: 11 females, mean age 51; test: nine females, mean age 48). Although there was no significant difference in the PES between the groups (control: 10.11; test: 10.48; p = .577), the MSI was significantly lower in the test (1.10) than in the control group (2.53) (p = .017). Based on descriptive statistics, the latter demonstrated wider scars, more colour mismatch and slightly more suture marks. However, these were not considered disturbing by the patients given similar VAS on soft tissue aesthetics (control: 84; test: 87). Oedema and haematoma were rated twice as high in the control group on at least two postoperative time points, and patients took more painkillers (7.10 vs. 4.86). OHIP-14 decreased in both groups between baseline and 1-year follow-up, indicative of less discomfort in daily life. Differences in MSI and PROMs between the groups may be explained by the need of a vertical releasing incision in order to achieve sufficient access for GBR, periosteal incisions and the use of biomaterials that may induce inflammation. CONCLUSION: GBR and CTG resulted in favourable aesthetic outcomes as assessed by professionals and patients. However, given additional vertical and periosteal incisions, GBR resulted in more scarring, postoperative discomfort and a higher need for painkillers.

A randomized controlled trial on the efficiency of free-handed, pilot-drill guided and fully guided implant surgery in partially edentulous patients.

OBJECTIVES: To compare the effectiveness of free-handed (FH), pilot-drill guided (PG) and fully guided (FG) implant surgery by means of the apical global deviation (AGD) in relation to the additional financial cost and time spent. MATERIALS AND METHODS: Thirty-three partially edentulous patients in need of ≥2 implants in the posterior maxilla were randomly allocated to one of the following treatment groups: FH, PG and FG. Eleven patients (mean age 57; eight females; altogether 26 implants) were treated by FH surgery, 11 (mean age 53; seven females; altogether 24 implants) by PG surgery and 10 (mean age 60; six females; altogether 21 implants) by FG surgery. The accuracy in implant positioning was assessed by comparing the actual implant position to its planned position with the AGD as the main measure of effectiveness. Cost analysis included data on time investment (pre- and per-operative) and operational cost. The efficiency of PG and FG surgery was assessed by means of the incremental cost-effectiveness ratio (ICER), defined as the extra investment that is needed per unit reduction in AGD when compared to FH surgery. RESULTS: FG surgery was most effective (mean AGD: 0.97 mm) and FH surgery was least effective (mean AGD: 2.11 mm) in terms of surgical accuracy. As a result, 5/26 implants had to be restored with a cement-retained restoration following FH surgery, although screw-retention was planned for all implants in every group. The total time investment did not differ significantly between the 3 groups (p = 0.811). A significant additional cost per implant was found for PG and FG as compared to FH surgery pointing to 8.29% (€176.54) and 10.45% (€222.52), respectively (p < 0.001). The ICER revealed an additional cost of €5.48 and €4.12 per per cent reduction in AGD for PG and FG surgery, respectively. CONCLUSION: The extra operational cost for guided implant surgery is acceptable and clinically justified since cementation can be avoided. FG surgery is the most efficient surgical approach, even though the absolute operational cost is higher when compared to PG and FH surgery.

A 5-year prospective study on the clinical and aesthetic outcomes of alveolar ridge preservation and connective tissue graft at the buccal aspect of single implants.

AIM: To evaluate the 5-year aesthetic outcome of single implants following alveolar ridge preservation (ARP) and connective tissue graft (CTG) at the buccal aspect. MATERIALS AND METHODS: Thirty-seven periodontally healthy non-smoking patients received flapless tooth extraction, ARP with a deproteinized bovine bone mineral with 10% collagen (DBBMC), implant placement (4-6 months later), a provisional screw-retained crown and CTG at the buccal mucosa (3 months later) and a permanent crown (3 months later). The aesthetic results were the primary outcome and the clinical results the secondary outcome of the study. Both outcomes were compared to those after 1 year. Mucosal thickness (MT) was registered using a non-invasive ultrasonic device. RESULTS: Thirty-two patients attended the 5-year re-assessment, and all implants survived. Mean marginal bone loss was 0.53 mm at 1 year and 0.47 mm at 5 years (p = 0.439). Mesial Papilla showed a further re-growth between 1 and 5 years (p = 0.043). Mid-facial recession amounted to 0.05 mm and 0.12 mm at 1 and 5 years, respectively (p = 0.161). The Pink Esthetic Score was 11.00 and 11.17 at 1 and 5 years, respectively (p = 0.596). MT gain amounted to 0.97 mm (relative stability: 90.5%) and 0.91 mm (relative stability: 85%) at 1 and 5 years, respectively (p = 0.249). CONCLUSION: ARP and CTG resulted in favourable clinical and aesthetic outcomes. CTG substantially increased MT with acceptable stability over a 5-year period.

A randomized controlled study on the accuracy of free-handed, pilot-drill guided and fully guided implant surgery in partially edentulous patients.

AIM: To compare the accuracy of free-handed (FH), pilot-drill guided (PG) and fully guided (FG) implant surgery. MATERIALS AND METHODS: Partially edentulous patients in need of ≥2 implants in the posterior maxilla were randomly allocated to one of the following treatment groups: FH, PG and FG. Ideal implant positions were determined in designated software following the fusion of bony information (CBCT data in DICOM format) to the prosthetic wax-up (optical scan data in STL format). The position of every implant as surgically realized was compared to its "ideal position". The apical global deviation (AGD) was the primary outcome of the study. Secondary outcome variables were angular deviation (AD), coronal global deviation (CGD), coronal lateral deviation (CLD), coronal vertical deviation (CVD), apical lateral deviation (ALD) and apical vertical deviation (AVD). RESULTS: Eleven patients (mean age 57; three males; eight females; altogether 26 implants) were treated by FH surgery, 11 (mean age 53; four males; seven females; altogether 24 implants) by PG surgery and 10 (mean age 60; four males; six females; altogether 21 implants) by FG surgery. FG surgery was most accurate (mean AGD: 0.97 mm; maximum AGD: 1.98 mm) followed by PG surgery (mean AGD: 1.43 mm; maximum AGD: 2.72 mm). FH surgery resulted in huge deviation from the ideal position (mean AGD: 2.11 mm; maximum AGD: 4.84 mm). The results on most secondary outcome variables followed the same order. Although screw-retained restorations were planned for all implants, five of 26 in the FH group and one of 24 in the PG group had to be restored by means of a cement-retained restoration. CONCLUSION: When perfect implant positioning is required, FG surgery should be considered the gold standard approach.

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.

A 5-year prospective study on regenerative periodontal therapy of infrabony defects using minimally invasive surgery and a collagen-enriched bovine-derived xenograft.

AIM: The primary objective of this study was (1) to evaluate the 5-year clinical outcome of regenerative periodontal therapy (RPT) using minimally invasive surgery and a collagen-enriched bovine-derived xenograft and (2) to identify predictors for clinical attachment level (CAL) gain and vertical radiographic bone (RB) gain. MATERIALS AND METHODS: Ninety-five non-smoking patients with ≤ 25% full-mouth plaque and bleeding presenting ≥ 6 months after initial periodontal therapy with ≥ 1 isolated interdental infrabony defect were recruited. Minimally invasive surgery (MIST or M-MIST) and a collagen-enriched bovine-derived xenograft were used in all patients. Patients were surgically treated by the same clinician and evaluated up to 5 years of follow-up. Multivariate analyses were used to identify predictors for CAL gain and RB gain. RESULTS: Before surgery, mean probing depth (PD) was 7.8 mm, CAL was 10.0 mm, and defect depth amounted to 5.2 mm. Seventy-one patients (33 men, 38 women, mean age 52) could be evaluated at 5 years. Mean PD reduction was 3.3 mm (SD 2.2), CAL gain was 3.0 mm (SD 2.1), and RB gain was 57% (SD 38). Forty-five percent showed ≥ 4 mm CAL gain, whereas 24% were considered failures (≤ 1 mm CAL gain). Forty-eight percent showed considerable RB gain (≥ 75%). Regression analyses showed that plaque was a significant predictor for CAL gain (p = 0.001) and RB gain (p = 0.005). Patients' compliance had a significant impact on RB gain (p < 0.001). CONCLUSION: Only patients with perfect oral hygiene and excellent compliance should be considered for RPT. Especially, the latter can only be assessed after sufficient follow-up following initial periodontal therapy. CLINICAL RELEVANCE: RPT failed in 24% of the patients after 5 years. Regression analyses demonstrated a significant impact of plaque and patients' compliance on the long-term outcome. Only patients with perfect oral hygiene and excellent compliance should be considered for RPT. Patients should not be treated too soon following initial therapy, since compliance can only be reliably assessed after sufficient follow-up.

Patient-Reported Outcomes After Lateral Wall Sinus Floor Elevation: A Systematic Review.

OBJECTIVES: The aim of this systematic review is to assess patient-reported outcome measures (PROMs) after a sinus lift elevation by means of a lateral approach. MATERIAL AND METHODS: An electronic search was performed to search for eligible publications reporting PROMs after a lateral wall sinus lift procedure. Selected articles were further scrutinized and underwent a quality check before inclusion in a final study pool. RESULTS: The electronic search provided us with 2444 articles of which 98 were further examined through a full-text analysis. Of these 98 studies, 11 were selected based on our inclusion and exclusion criteria. Results on a different number of PROMs were examined and compared: pain, edema, ability to eat, ability to work, phonetics, daily activities, bleeding, bruising, ability to sleep, bad breath, patient preference, and Oral Health Impact Profile-14 (OHIP-14). Methods of evaluation were 3- to 5-point scales, visual analog scale scores, and OHIP-14 questionnaires. Evaluation time points differed between 1 single evaluation time to a daily registration during 1 week. CONCLUSIONS: A general peak in discomfort could be noticed on day 1 postoperatively with a general decline thereafter. Severe morbidity or discomfort occurred but not in most patients.

Relationship between buccal bone and gingival thickness revisited using non-invasive registration methods.

OBJECTIVE: To determine the relationship between buccal bone and soft tissue thickness at teeth in the premaxilla by means of non-invasive registration methods. MATERIALS AND METHODS: Buccal bone thickness at central incisors, lateral incisors and canines was measured at five reference points (1-5 mm from the top of the alveolar crest) on CB-CT scans of 21 patients. The corresponding buccal gingival thickness was measured by the use of an ultrasonic device. Spearman's correlation coefficient was calculated to assess the correlation between buccal bone and soft tissue thickness at each tooth type. RESULTS: Mean buccal bone thickness (SD) at central incisors, lateral incisors and canines was 1.07 mm (0.34 mm), 1.16 mm (0.54 mm) and 0.98 mm (0.37 mm), respectively. For central incisors, 68% of all sites had a thickness <1 mm and 32% had a thickness between 1.0 and 2.0 mm. At lateral incisors, 44% demonstrated buccal bone thickness between 0 and 1.0 mm, 48% between 1.0 and 2.0 mm and 8% ≥2 mm. For canines, 57% of the sites were <1 mm thick; 41% were between 1.0 and 2.0 mm thick, and 2% demonstrated ≥2 mm thickness. Mean gingival thickness (SD) at central incisors, lateral incisors and canines was 1.37 mm (0.32 mm), 1.33 mm (0.32 mm) and 1.08 mm (0.25 mm), respectively. The correlation between buccal bone and soft tissue thickness was moderately positive (ρ = 0.406; P < 0.001). CONCLUSIONS: A thin buccal bone wall (<1 mm) may be expected in over half of the central incisors and canines. The correlation between buccal bone and soft tissue thickness was moderately positive.

Horizontal stability of connective tissue grafts at the buccal aspect of single implants: a 1-year prospective case series.

AIM: To clinically evaluate the horizontal stability of a connective tissue graft (CTG) at the buccal aspect of single implants (1); to compare actual gingival thickness between thin and thick gingival biotype (2). MATERIALS AND METHODS: Periodontally healthy non-smoking patients with a single implant in the anterior maxilla (15-25) were selected for a prospective case series. All demonstrated a horizontal alveolar defect and were in need of contour augmentation by means of CTG for aesthetic reasons. Patients were enrolled 3 months after implant surgery and had been provided with a provisional screw-retained crown. CTG was inserted in the buccal mucosa via the envelope technique using one intrasulcular incision. An ultrasonic device was used to evaluate mucosal thickness (MT) at the buccal aspect. MT was assessed at t0 (before CTG), t1 (immediately after CTG), t2 (2 weeks after CTG = suture removal), t3 (3 months after CTG = permanent crown installation) and t4 (1 year after implant placement). The gingival biotype was categorized as thin or thick based on the transparency of a periodontal probe through the soft tissues while probing the buccal sulcus of the contra-lateral tooth. Gingival thickness (GT) was measured at the contra-lateral tooth using the same ultrasonic device. RESULTS: Thirty-seven patients (19 men, 18 women; mean age 38) met the selection criteria and consented to the treatment. Mean soft tissue gain immediately after CTG was on average 1.07 mm (SD 0.49). What remained of this tissue gain after 1 year was on average 0.97 mm (SD 0.48; 90.5%). Hence, mean soft tissue loss amounted to 0.10 mm (SD 0.23; 9.5%; p = 0.015) with no significant difference between patients with a thin or thick biotype (p ≥ 0.290). Patients with a thin biotype had a mean GT of 1.02 mm (SD 0.21), whereas GT was on average 1.32 mm (SD 0.31) in subjects with a thick biotype (p = 0.004). CONCLUSION: Connective tissue graft substantially thickens the peri-implant mucosa with acceptable stability over a 1-year period.

Lateral bone augmentation with a composite graft covered with a stretched and pinned collagen membrane: A retrospective case series using cone-beam computed tomography.

AIMS: (1) To assess the effectiveness of the Sausage Technique™ when applied for lateral bone augmentation by multiple experienced clinicians; (2) To identify risk indicators for a poor outcome and to assess the need for adjunctive surgery. MATERIALS AND METHODS: All patients who had been treated with the Sausage Technique™ for lateral bone augmentation by three experienced surgeons between January 2019 and December 2021 were included in a retrospective case series. The Sausage Technique™ technique includes the use of autogenous bone chips and deproteinized bovine bone mineral (1:1 ratio), covered with a stretched and pinned collagen membrane. The increase in alveolar width between the pre-operative situation and 9 months was assessed at different levels on superimposed cone-beam CT scans. RESULTS: Twenty-five augmentations performed in 25 patients (17 males, 8 females, mean age 51 years) were available for evaluation. Mean alveolar width increased from 4.35 to 7.43 mm at 3 mm below the crest. The mean increase of 3.08 mm (95% CI 2.10-4.06; p < 0.001) was significant. The outcome of non-containing single implant sites was significantly worse than the outcome of other sites (MD 2.67 mm; p = 0.008). The need for regrafting was 4% and the need for soft tissue augmentation was 48%. Twenty percent of the patients needed soft tissue augmentation due to a lack of keratinized mucosa width, and 32% due to a lack of buccal convexity. The former was mainly needed at multiple implant sites, whereas the latter was mainly required at single implant sites. All implant survived and remained healthy until the final follow-up. CONCLUSION: The Sausage Technique™ is an effective bone augmentation technique. Non-containing single implant sites were associated with a poor outcome and adjunctive soft tissue augmentation was needed in about half of the patients.

Accuracy of immediately placed implants using surgical guides from different 3-dimensional printers: An in vitro study.

AIM: The aim of this study was to evaluate the accuracy of 3-dimensional (3D)-printed surgical guides for fully guided immediate implants from different manufacturers. METHODS: Eighteen 3D printed fully guided surgical guides (split into 3 groups [n = 6] according to their manufacturer: Company, Desktop, or Lab), were used to place 72 implants (n = 24) in identical maxillary models. After placement, the mean global, angular, mesiodistal, buccopalatal, and vertical deviation at the platform and apex of the placed implants, relative to their preoperatively planned positions, was calculated. RESULTS: Significant differences in global apex deviation, angular deviation, mesiodistal apex deviation, and vertical platform and apex deviation were found between the Lab and Desktop groups (p ≤ 0.007). Significant differences in mesiodistal platform and apex deviation and buccopalatal apex deviation were also found between the Company and Desktop groups (p ≤ 0.005). Finally, significant differences in buccopalatal apex deviation, and vertical platform and apex deviation were found between the Company and Lab groups (p ≤ 0.003). Mean differences between guide groups across all parameters never exceeded 0.5 mm or 1°. CONCLUSIONS: The choice of 3D printer has a significant effect on the accuracy of fully guided immediate implants. However, the clinical relevance of these differences may be considered limited.

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 randomized controlled study comparing guided bone regeneration with connective tissue graft to reestablish buccal convexity at implant sites: A 1-year volumetric analysis.

OBJECTIVES: To volumetrically compare guided bone regeneration (GBR) with connective tissue graft (CTG) to reestablish 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 clinical trial (RCT). All sites had a buccopalatal bone dimension of at least 6 mm, received a single implant, and were randomly allocated to the control (GBR) or test group (CTG) to reestablish buccal soft tissue convexity. Patients received a provisional crown at 3 months and a permanent crown at 6 months. Primary outcomes were volumetric increase (mm3 ) and linear increase (mm) in buccal soft tissue profile (BSP) within a well-defined area of interest at fixed time points. Alveolar process deficiency was a secondary outcome. RESULTS: Twenty-one patients were included per group (control: 11 females, mean age 51; test: 9 females, mean age 48). After 1 year, GBR resulted in a significant volumetric increase of 20.74 mm3 (P < .001) corresponding to linear increase in BSP of 1.30 mm (P < .001). For CTG, this was 15.86 (P < .001) and 1.19 mm (P < .001), respectively. The changes over time in volume (P = .173) and BSP (P = .241) were not significantly different between the groups. Twenty-nine percentage and 26% of the final volumetric increase was the result of installing and altering prosthetic components in the control and test groups, respectively. Alveolar process deficiency significantly reduced from pre-op to 1 year following GBR (P < .001) and CTG (P < .001). The difference between the groups was not significant (P = .342). However, 58% of the patients treated with GBR and 38% treated with CTG failed to show perfect soft tissue convexity at the buccal aspect. CONCLUSION: GBR as well as CTG are effective in reducing horizontal alveolar defects for aesthetic purposes. However, in about half of the cases, either strategy failed to optimally reestablish buccal convexity.

A 2-year prospective case series on volumetric changes, PROMs, and clinical outcomes following sinus floor elevation using deproteinized bovine bone mineral as filling material.

BACKGROUND: A sinus floor augmentation may be indicated when a lack of hard tissue impedes implant placement. Although clinically successful, evidence supporting the long-term three-dimensional stability of the grafted volume is scarce. Second, evidence on the patient's acceptance of this type of treatment is limited. PURPOSE: First is to evaluate the changes in graft volume after lateral wall sinus lifting based on superimposed cone beam computed tomography (CBCT) images and then to assess patient-reported outcome measures (PROMs) and clinical outcomes. MATERIALS AND METHODS: Partially edentulous patients in need of a sinus lift and fixed reconstruction on at least two neighboring implants were selected for a prospective case series. Lateral wall sinus augmentation was performed using deproteinized bovine bone mineral (DBBM) as the only filling material. Volumetric changes were quantified on the basis of a preoperative CBCT and three postoperative CBCTs (at 2 weeks, 3 months, and 2 years). PROMs and clinical parameters were registered. RESULTS: Twenty-two patients (7 males, 15 females; mean age 59 years) participated of which three patients dropped out during the follow up. Graft volumes amounted to 1418.26 mm3 at 2 weeks, 1201.21 mm3 at 3 months, and 1130.13 mm3 at 2 years postoperative pointing to a relative graft volume stability of 79.7%. Swelling was the leading symptom during the first week. A peak in visual analogue scale scores was observed for pain, swelling, and hematoma the day of surgery and 1 day postoperation with a statistically significant decline between days 3 and 7. Hemorrhage and nose bleeding occurred in 18.2% and 27.3% of the subjects, respectively. About 95.5% of the subjects would undergo the treatment again. All implants integrated successfully and demonstrated healthy clinical conditions. CONCLUSION: Lateral wall sinus augmentation using DBBM as the only filling material is a viable treatment concept given limited graft resorption, good patients' tolerance, and clinical outcomes.

A retrospective cohort study of metal-cast resin- bonded fixed dental prostheses after at least 16 years.

PURPOSE: This retrospective cohort study evaluated metal-cast silan-coated three-unit resin-bonded fixed dental prostheses (RBFDPs) after at least 16 years and identified covariates affecting the survival. MATERIALS AND METHODS: A total of 37 patients with 42 RBFDPs placed by one operator between 1986 and 1993 were recalled and invited for a clinical examination in conjunction with scrutiny of clinical records. RESULTS: Thirteen RBFDPs were lost to follow-up after an average of 58.5 months (SD = 39.4) and considered unaccounted for, 10 failed prior to the research recall and had a survival of 130.2 months (SD = 68.3), and 19 were still in function with a mean survival of 236.2 months (SD = 24.7). The estimated, cumulative survival via Kaplan-Meier analysis of the total number of 43 RBFDPs resulted in 95% (SE = 4%) survival after 5 years, 88% (SE = 6%) after 10 years and 66% (SE = 9%) after 20 years. No covariates were found having a significant effect on the survival rates. CONCLUSIONS: RBFDPs have an acceptable clinical survival although lower than conventional FDPs and single implants. They should therefore be considered as a temporary provision, as a provision for geriatric or medically-compromised patients because of the simplicity of the provision, as a less expensive alternative, and for patients where the amount of bone loss impedes the use of dental implants.