PURPOSE:This study was performed to evaluate the effects of flap design, grafting material, and graft dimension on flap tension and the initial volume increase achieved in soft tissue augmentation. METHODS:Six fresh porcine jaw cadavers were used in this study. Each side of the jaw was randomly assigned to receive either a standard split-thickness flap or a split-thickness flap with a palatal island. Following flap preparation, random allocation was employed to determine the order of 4 treatment modalities: 3 mm of a volume-stable collagen matrix (VCMX), 6 mm VCMX, 3 mm of a subepithelial connective tissue graft (SCTG), and 6 mm SCTG. Flap tension was measured and the wound was closed after the insertion of each specimen. Intraoral scans were taken before flap preparation and after closure to facilitate profilometric analysis. RESULTS:The palatal island flap exhibited significantly greater overall (P=0.010) and crestal (P=0.007) volume gains compared to the split-thickness flap, regardless of the use of VCMX or SCTG. The palatal island flap was associated with significantly lower flap tension force values (0.6 N; P=0.035) than the split-thickness flap. Both materials (VCMX and SCTG) demonstrated comparable volume gains. CONCLUSIONS:The findings of this cadaveric study indicate that the use of a palatal island flap effectively reduces flap tension. While both materials (VCMX and SCTG) yielded similar increases in volume, the palatal island flap demonstrated greater volume gains than the split-thickness flap for each grafting material.

ABSTRACT Aim To compare the histological structure of biopsies from the anterior and posterior regions of the human palate in order to gain insights into potential differences of soft tissue harvesting sites. Methods This comparative study involved 20 participants, from each of whom four samples from the palatal mucosa were collected. The biopsies were histologically processed and subsequently analysed. The thickness of the epithelium, lamina propria, and the length of the rete pegs were measured using a microscope. In addition, parameters such as collagen fibres, elastic fibres, elastic connective tissue, loose connective tissue and the background were measured. Results The mean epithelial thickness was 0.42 mm anteriorly and 0.37 mm posteriorly. The mean thickness of the lamina propria was 0.81 mm anteriorly and 0.85 mm posteriorly. Within the region of interest, collagen fibres were significantly less abundant anteriorly than posteriorly ( p = 0.016). The loose connective tissue showed a significantly higher occurrence in the anterior compared with the posterior sampling site ( p = 0.004). Conclusion This trial indicates no differences in terms of the thickness of the lamina propria. There was a higher concentration of collagen fibres and a lower concentration of loose connective tissue in the posterior region of the palate.

OBJECTIVE:To assess the clinical, radiographic and patient-reported outcomes (PROMs) of posterior zirconia and titanium implants at 1 year of implant loading. MATERIALS AND METHODS:Forty-two patients with two adjacent missing teeth were enrolled in a randomized controlled trial with a within-subject controlled design. Each patient received one zirconia (Zr) and one titanium (Ti) implant, with the mesial and distal positions randomized. The implant restoration consisted of multiple layered zirconia, with the buccal aspect veneered. In group Zr, the restoration was intraorally cemented onto the one-piece Zr implant, whereas in group Ti, the restoration was extraorally cemented onto the titanium base abutment and intraorally screw-retained onto the Ti implant. Examinations were performed following restoration delivery at baseline (BL) and at 1 year. Measurements included clinical parameters, radiographic outcomes (MBL) and PROMs. RESULTS:Bleeding on probing showed an increase from BL to 1 year (34 ± 30% for Zr; 25 ± 21% for Ti). MBL remained stable with minimal changes from BL to 1 year, measuring 0.1 ± 0.4 mm (mean ± SD) for Zr and -0.1 ± 0.7 mm for Ti. Veneering fractures were the most frequent technical complication and amounted to 17.5% in group Zr and 5% in group Ti (p = .100). Patients preferred Zr implants for their soft tissue color, with a significant difference in perception between patients and clinicians (p < .017). CONCLUSION:The study showed that both Zr and Ti implants had similar clinical outcomes, despite a high prevalence of mucositis and a few technical complications. Both implant types demonstrated stable marginal bone levels and similar patient-reported outcome measures.

ObjectivesTo report on soft tissue contour changes at pontic sites with or without soft tissue grafting over an observation period of 15 years.MethodsFourteen patients received a fixed dental prosthesis (FDP) in the posterior zone in a controlled clinical study and were available at the 15-year follow-up. Eight patients received a subepithelial connective tissue graft in the pontic area (test) while six received the FDP without soft tissue grafting (control). Impressions were taken after FDP cementation and at 15 years. Casts were digitized and a profilometric analysis was performed (mean distance) and the pontic height (PH) and ridge width (RW) were analyzed at the mid-buccal area. A descriptive analysis and Wilcoxon-Mann-Whitney test was performed (level of significance: 5%).ResultsProfilometric changes (mean distance) from baseline to 15 years amounted to -0.68 mm (test) and to -0.33 mm (control) (p = 0.208), 95% CI for group difference (0.290; -0.750). PH measured -0.47 mm (test) and 0.0 mm (control) (p = 0.079) and RW amounted to -1.05 mm (test) and -0.38 mm (control) (p = 0.138).ConclusionRemodeling of the soft tissue contour at pontic sites of FDPs was evident in both groups, but slightly more accentuated following soft tissue grafting.Clinical SignificanceThis study is the first to report on soft tissue changes at pontic sites over more than 10 years. It investigates whether tissue contour changes with and without soft tissue grafting before the insertion of FDPs. Remodeling of the soft tissue contour at pontic sites was observed over 15 years, with more pronounced changes when soft tissues were augmented with SCTGs before FDP insertion. The volume loss at the augmented site must be considered in relation to the overall tissue changes over long periods. Connective tissue grafts reliably improve shape and esthetics around the pontic unit. Further long-term studies with more patients are needed to evaluate the initial gains and long-term performance of these augmentations.

AIM:To evaluate the progression of wound healing of standardized palatal defects in groups using three different collagen-based wound dressings and a control group, in terms of wound closure, pain perception and descriptive histology.MATERIALS AND METHODS:Twenty participants were enrolled in this experimental study, in whom four palatal defects were created. The defects (6 mm diameter, 3 mm depth) were randomly assigned to one of four treatment modalities: C (control), MG (Mucograft®), MD (mucoderm®) and FG (Fibro-Gide®). Photographs were taken, and pain assessment was performed before and after treatment and at 5, 7, 9, 12, 14 and 16 days after surgery. All participants wore a palatal splint for a duration of 16 days.RESULTS:All groups achieved complete wound closure at 14 days. The percentage of the remaining open wound on day 7 amounted to 49.3% (C; interquartile range [IQR]: 22.6), 70.1% (FG; IQR: 20.7), 56.8% (MD; IQR: 26.3) and 62.2% (MG; IQR: 34.4). Statistically significant differences were found between FG and C (p =.01) and between MD and FG (p =.04). None of the participants rated pain higher than 4 out of 10 during the entire study period.CONCLUSIONS:Collagen-based wound dressings provide coverage of open defects, albeit without acceleration of wound closure or reduction of pain. FG (which is not intended for open oral wounds) showed slower wound closure compared to C and MD.

PURPOSE:The aim of this study was to compare changes in soft and hard tissue and the histologic composition following early implant placement in sites with alveolar ridge preservation or spontaneous healing (SH), as well as implant performance up to 1 year after crown insertion.METHODS:Thirty-five patients with either intact buccal bone plates or dehiscence of up to 50% following single-tooth extraction of incisors, canines, or premolars were included in the study. They were randomly assigned to undergo one of three procedures: deproteinized bovine bone mineral with 10% collagen (DBBM-C) covered by a collagen matrix (DBBM-C/CM), DBBM-C alone, or SH. At 8 weeks, implant placement was carried out, and cone-beam computed tomography scans and impressions were obtained for profilometric analysis. Patients were followed up after the final crown insertion and again at 1 year post-procedure.RESULTS:Within the first 8 weeks following tooth extraction, the median height of the buccal soft tissue contour changed by -2.11 mm for the DBBM-C/CM group, -1.62 mm for the DBBM-C group, and -1.93 mm for the SH group. The corresponding height of the buccal mineralized tissue changed by -0.27 mm for the DBBM-C/CM group, -2.73 mm for the DBBM-C group, and -1.48 mm for the SH group. The median contour changes between crown insertion and 1 year were -0.19 mm in the DBBM-C/CM group, -0.09 mm in the DBBM-C group, and -0.29 mm in the SH group.CONCLUSIONS:Major vertical and horizontal ridge contour changes occurred, irrespective of the treatment modality, up to 8 weeks following tooth extraction. The DBBM-C/CM preserved more mineralized tissue throughout this period, despite a substantial reduction in the overall contour. All 3 protocols led to stable tissues for up to 1 year.

OBJECTIVES:To evaluate the volumetric changes and peri-implant health at implant sites with and without previous soft tissue grafting over a 12-year observation period.MATERIALS AND METHODS:Eighteen patients received dental implants and simultaneously guided bone regeneration in the esthetic zone (15-25) for dental rehabilitation. Three months following implant placement, 8 patients (test) received an additional subepithelial connective tissue graft, whereas 10 patients (control) did not receive any additional treatment. One week after prothesis delivery and at the 5 and 12 years follow-up examination, impressions were taken. Obtained casts were processed for profilometric and linear analyses. The mean distance (MD) in the mid-buccal area between the two surfaces was considered the primary outcome. Peri-implant health was assessed based on clinical and radiographic data.RESULTS:Nine female and 7 male patients were re-assessed after a median follow-up time of 144.5 months (Min: 114.8; Max: 213.0). The median reduction of MD amounted to -0.81 mm (Min: -1.39; Max: 0.52) in the test group and -0.56 mm (Min: -0.93; Max: 0.11) in the control group, (intergroup comparison p = .607, CI 95%: -0.760/0.530). None of the implants was diagnosed with peri-implantitis. Six tests and two control implants were diagnosed with peri-implant mucositis (p = .103).CONCLUSIONS:Despite the limited number of included patients, similar results in terms of volumetric, linear changes, and peri-implant conditions could be detected at implant sites with or without soft tissue grafting over a period of 12 years.

To analyze the influence of compression on tissue integration and degradation of soft tissue substitutes. Six subcutaneous pouches in twenty-eight rats were prepared and boxes made of Al2O3 were implanted and used as carriers for soft tissue substitutes: a collagen matrix (MG), two volume-stable collagen matrices (FG/MGA), and a polycaprolactone scaffold(E). The volume-stable materials (FG/MGA/E) were further implanted with a twofold (2) and a fourfold (4) compression, created by the stacking of additional layers of the substitute materials. The samples were retrieved at 1, 2, and 12 weeks (10 groups, 3 time points, n = 5 per time point and group, overall, 150 samples). The area fraction of infiltrated fibroblasts and inflammatory cells was evaluated histologically. Due to within-subject comparisons, mixed models were conducted for the primary outcome. The level of significance was set at 5

AIMTo compare subepithelial connective tissue grafts (SCTG) versus guided bone regeneration (GBR) for the treatment of small peri-implant dehiscence defects in terms of profilometric (primary outcome), clinical, and patient-reported outcome measures (PROMs).METHODSSixteen patients who presented with small buccal bone dehiscences (≤3 mm) following single implant placement were recruited. Following implant placement, buccal bone defect sites were randomly treated either with a SCTG or GBR. Six patients who lacked bone dehiscences after implant placement were assigned to a negative control. Transmucosal healing was applied in all patients. Patients were examined prior (T1) and after (T2) implant placement, at suture removal (T3), at implant impression (T5), at crown delivery (T6), and 12 (T7) months after crown delivery. Measurements included profilometric outcomes, marginal bone levels, buccal bone and soft tissue thickness, PROMs, and clinical parameters. All data were analyzed descriptively.RESULTSThe median changes in buccal contour as assessed by profilometric measures between T1 and T5 showed a decrease of 1.84 mm for the SCTG group and 1.06 mm for the GBR group. Between T2 and T7, the median change in the buccal contour amounted to 0.45 mm for SCTG and -0.94 mm (=loss) for GBR. Patients' pain perception tended to be higher in SCTG than in GBR. All peri-implant soft tissue parameters showed healthy oral tissues and no clinically relevant differences between groups.CONCLUSIONWithin the limitations of this pilot study, treating small peri-implant dehiscence defects with a SCTG might be a viable alternative to GBR. The use of a SCTG tended to result in more stable profilometric outcomes and comparable clinical outcomes to GBR. However, patient-reported outcome measures tended to favor GBR.

AIM:To test whether soft-type block bone substitute used for guided bone regeneration (GBR) of peri-implant defects leads to a different dimension of the augmented hard tissue than particulate bone substitute.MATERIALS AND METHODS:In 40 patients, 40 two-piece dental implants were placed >2 months after tooth extraction. Following random allocation, 20 peri-implant bone dehiscences were grafted with a soft-type block made of synthetic biphasic calcium phosphate (BCP) + collagen and 20 bone dehiscences with particulate BCP. All the sites were covered with a collagen membrane stabilized with titanium pins. Immediately after wound closure and after 6 months, the horizontal dimension (HD) of the augmented hard tissue was measured at the level of implant shoulder using cone beam computed tomography. During re-entry at 6 months, the defect fill was clinically assessed.RESULTS:At 6 months, the median HD measured 1.15 mm (mean: 1.31 mm) in the soft-block group and 0.93 mm (mean: 1.05 mm) in the particulate group (p = .6). At 6 months, 7.1% of contained defects and 61.9% of non-contained defects showed an incomplete vertical defect fill.CONCLUSIONS:Soft-type block of BCP + collagen used for GBR of peri-implant defects did not differ from particulate BCP regarding the dimension of the augmented hard tissue after 6 months of healing.

AIM:The purpose of the present retrospective case series was to introduce a minimally invasive two-stage flapless crown lengthening procedure where a gingivectomy was avoided or minimized by reducing the bone height through a tunneling technique.MATERIALS AND METHOD:Ten patients (median age 46.6 years, range 26.9 to 71.6 years) were included in the study. The indications for performing a crown lengthening procedure were esthetically short clinical crowns (n = 5), asymmetry of the gingival margin level (n = 2), and both esthetically short clinical crowns and asymmetry of the gingival margin level (n = 3). All the patients presented a thick gingival phenotype, and the mean number of operated teeth per patient was 3.7 (range 2 to 8 teeth). Three patients underwent an additional gingivectomy 6 weeks after the crown lengthening procedure.RESULTS:The esthetic and functional outcome of the treatments fulfilled the patients' and dentist's expectations.CONCLUSION:A minimally invasive two-stage crown lengthening procedure applying a tunneling technique has the potential to achieve predictable esthetic outcomes without an open-flap approach and an additional gingivectomy. However, prospective clinical studies are needed to validate this technique.

OBJECTIVES:The aim of this study was to comprehensively assess the literature in terms of the effect of peri-implant mucosal thickness on esthetic outcomes and the efficacy of soft tissue augmentation procedures to increase the mucosal thickness with autogenous grafts or soft tissue substitutes.MATERIAL AND METHODS:Two systematic reviews (SR) were performed prior to the consensus meeting to assess the following questions. Review 1, focused question: In systemically healthy patients with an implant-supported fixed prosthesis, what is the influence of thin as compared to thick peri-implant mucosa on esthetic outcomes? Review 2, focused question 1: In systemically healthy humans with at least one dental implant (immediate or staged implant), what is the efficacy of connective tissue graft (CTG), as compared to absence of a soft tissue grafting procedure, in terms of gain in peri-implant soft tissue thickness (STT) reported by randomized controlled clinical trials (RCTs) or controlled clinical trials (CCTs)? Review 2, focused question 2: In systemically healthy humans with at least one dental implant (immediate or staged implant), what is the efficacy of CTG, as compared to soft tissue substitutes, in terms of gain in peri-implant STT reported by RCTs or CCTs? The outcomes of the two SRs, the consensus statements, the clinical implications, and the research recommendations were discussed and subsequently approved at the consensus meeting during the group and plenary sessions.CONCLUSIONS:There was a tendency of superior esthetic outcomes in the presence of a thick mucosa. The connective tissue graft remains the standard of care in terms of increasing mucosa thickness.

AbstractObjectivesIn systematically healthy patients with an implant‐supported fixed restoration (P), what is the influence of thin (E) as compared to thick (C) peri‐implant soft tissues on aesthetic outcomes (O)?MethodsFollowing an a priori protocol, a literature search of six databases was conducted up to August 2020 to identify prospective/retrospective clinical studies on healthy patients with an implant‐supported fixed reconstruction. Measurement of the buccal soft tissue thickness and an aesthetic outcome was a prerequisite, and sites presenting with a buccal soft tissue thickness of <2 mm or shimmering of a periodontal probe were categorized as a thin phenotype. After study selection, data extraction, and risk of bias assessment, random‐effects meta‐analysis of Mean Differences (MD) or Odds Ratios (OR) with their corresponding 95% Confidence Intervals (CI) were conducted, followed by sensitivity analyses and assessment of the quality of evidence.ResultsThirty‐four unique studies reporting on 1508 patients with 1606 sites were included (9 randomized controlled trials, one controlled trial, 10 prospective cohort studies, 8 cross‐sectional studies, and 6 retrospective cohort studies). The mean difference of the pink aesthetic score (PES) after the follow‐up was not significantly different between thin (<2.0 mm) or thick soft tissues (≥2.0 mm) or phenotypes (12 studies; MD = 0.15; [95% CI = −0.24, 0.53]; p = .46). PES changes during the follow‐up, however, were significantly in favour of thick soft tissues (≥2.0 mm) or phenotypes (p = .05). An increased mean mucosal thickness was associated with an increased papilla index (5 studies; MD = 0.5; [95% CI = 0.1, 0.3]; p = .002) and an increase in papilla presence (5 studies; OR = 1.6; [95% CI = 1.0, 2.3]; p = .03). Thin soft tissues were associated with more recession, −0.62 mm (4 studies; [95% CI = −1.06, −0.18]; p = .006). Patient‐reported outcome measures (patient satisfaction) were in favour of thick soft tissues −2.33 (6 studies; [95% CI = −4.70, 0.04]; p = .05). However, the quality of evidence was very low in all instances due to the inclusion of non‐randomized studies, high risk of bias and residual confounding.ConclusionWithin the limitations of the present study (weak study designs and various soft tissue measurements or time‐points), it can be concluded that increased soft tissue thickness at implant sites was associated with more favourable aesthetic outcomes.

AIM:To compare the peri-implant soft-tissue dimensional changes following guided bone regeneration between particulate (particle group) and collagenated soft-block-type (block group) biphasic calcium phosphate (BCP).MATERIALS AND METHODS:This study investigated 35 subjects: 18 in the particle group and 17 in the block group. Cone-beam computed tomography obtained at 6 months post surgery and optical impressions taken periodically (before surgery, 6 months post surgery, and 1 year post surgery) were superimposed. The ridge contour changes over time and the peri-implant mucosal thicknesses were measured diagonally and horizontally, and analysed statistically.RESULTS:The increases in diagonal (1.12 ± 0.78 mm) and horizontal (2.79 ± 1.90 mm) ridge contour of the block group were significantly higher than those in the particle group during the first 6 months (p < .05); however, the contour hardly changed thereafter (diagonal: 0.07 ± 0.75 mm; horizontal: -0.34 ± 1.26 mm), resulting in the 1-year contour changes similar between the two groups. Regardless of the type of BCP, the ridge contour increased significantly over 1 year when the dehiscence defect had a contained configuration (p < .05).CONCLUSIONS:The increase in soft-tissue dimensions for 1 year was similar between the two groups. The mucosal contour increase was larger when the surgery was conducted in a more contained defect, and this was not influenced by the type of BCP.

Abstract Aim The aim was to evaluate the performance of implants placed with simultaneous guided bone regeneration (GBR) using resorbable or nonresorbable membranes compared to implants placed in pristine bone without bone regeneration after an observation period of 22–24 years. Material and Methods The patient cohort of this clinical trial was treated from 1994 to 1996. Dehiscence defects were treated with GBR by either using resorbable collagen membranes (BG) or nonresorbable ePTFE membranes (GT). Implants placed in pristine bone served as a control (CT). Clinical parameters, marginal bone levels, and technical outcomes were evaluated following restoration placement and at the present follow‐up. A 3D radiographic analysis was conducted in order to assess buccal and oral bone dimensions. Implant survival was assessed with Kaplan–Meier analysis and a frailty model (level of significance 5%). Results Out of the originally 72 patients (mean age 75.4 ± 15.70 years) with 265 implants, 39 patients with 147 implants were included in the study after a median period of 23.5 years. Implant survival was 89.3% in group BG (n = 100), 90.2% in group GT (n = 37), and 93.8% in group CT (n = 105), without significant differences (Frailty proportional hazard model p = .79). Smoking had a negative effect on survival (p = .0122). Mean vertical marginal bone levels were −2.3 ± 1.4 mm (BG, n = 59), −3.0 ± 1.5 mm (GT, n = 21), and −2.3 ± 1.6 mm (CT, n = 52). The vertical buccal bone levels were −3.0 ± 1.9 mm (BG, n = 57), −3.5 ± 2.2 mm (GT, n = 21), and −2.6 ± 1.8 mm (CT, n = 49), without significant differences. Conclusion Implant placement with GBR procedures provides treatment outcomes with favorable implant survival rates (89.3%–93.8%) after 23.5 years. Smoking, however, affected implant survival negatively.

OBJECTIVES:To analyse the soft tissue morphology under healthy and experimental mucositis conditions comparing zirconia and titanium implants.METHODS:Forty-two patients with two adjacent missing teeth received one zirconia (Zr) and one titanium (Ti) implant, with the mesial and distal position randomized. At 3 months, half of the patients were instructed to continue (healthy; h) and the other half to omit (experimental mucositis; m) oral hygiene around the implants for 3 weeks. Clinical parameters were evaluated before and after the experimental phase, and a soft tissue biopsy was harvested. Mixed model analyses were performed to analyse the data.RESULTS:The plaque control record increased significantly for the two mucositis groups, reaching 68.3 ± 31.9% (mean ± SD) for Zr-m and 75.0 ± 29.4% for Ti-m (p < .0001), being also significantly lower for Zr-m than for Ti-m. Bleeding on probing remained stable in group Zr-m and amounted to 21.7 ± 23.6%, but increased significantly in group Ti-m (p = .040), measuring 32.5 ± 27.8%. The number of inflammatory cells and the length of the junctional epithelium did not significantly differ between the groups.CONCLUSION:Both implants rendered similar outcomes under healthy conditions. Lower plaque and bleeding scores were detected for zirconia implants under experimental mucositis conditions. Histologically, only minimal differences were observed.