Vertical Soft Tissue Research Articles

Porcine Cross-Linked Collagen Matrix for Peri-Implant Vertical Soft Tissue Augmentation: A Randomized Prospective Observational Study.

The mucosa height has always been of interest in modern implant dentistry to obtain biomimetic results. Papilla height, mucosa scalloping, and free mucosal margin level are crucial to achieve "pink aesthetics". The aim of this study was to investigate the vertical increase in the peri-implant soft tissues with a porcine cross-linked collagen matrix (Geistlich Fibro-Gide®). Methods: A total of 60 patients were divided into the following three groups: Group 1-patients who received porcine cross-linked collagen matrix for vertical soft tissue augmentation and a cover screw combined with a coronally advanced flap (CAF); Group 2-patients who received the collagen matrix combined with a healing abutment and CAF; Group 3 (control group)-patients who received a traditional surgical approach based on crestal incision and no collagen matrix as well as no CAF. Results: The average horizontal tissue thickness growth after 3 months was more effective for Group 1 (1.35 ± 1.23 mm) compared to Group 2 (0.85 ± 0.67 mm) and the control group (0.20 ± 0.41 mm). The average tissue height growth was 1.05 ± 1.39 mm for Group 1, 0.32 ± 1.28 mm for Group 2, and -0.05 ± 0.39 mm for the control group. Finally, the average increase in the band of keratinized mucosa was 0.60 ± 1.23 mm for Group 1, -0.60 ± 0.94 mm for Group 2, and 0.45 ± 0.60 mm for the control group. Conclusions: The combination of the CAF, porcine cross-linked collagen matrix, and cover screw resulted in better clinical results compared to Group 2 and 3.

Implant-Supported Vertical Soft Tissue Augmentation for Severe Hard and Soft Tissue Deficiencies at Malpositioned Implants: A Case Report of a Mucogingival and Restorative Approach.

The management of severe mucogingival deformities surrounding malpositioned implants represents a complex issue with a high risk of aesthetic failure. The present case report describes a mucogingival and restorative approach for the treatment of severe localized peri-implant tissue deficiencies with interproximal bone loss combined with an interproximal gingival recession on the adjacent natural tooth. This consists of maintaining a non-restorable malpositioned implant, submerging it through one or multiple vertical soft tissue augmentations, according to the defect severity, and delivering a tooth supported bridge involving the adjacent natural teeth. The step-by-step surgical technique adopted for implant submergence and vertical soft tissue grafting, as well as the subsequent surgical and prosthetic interventions, are described, presenting results at 5 years from implant submergence and 3 years from prosthetic finalization.

Implant-Supported Vertical Soft Tissue Augmentation for Severe Hard and Soft Tissue Deficiencies at Malpositioned Implants: A Case Report of a Mucogingival and Restorative Approach.

Implant-Supported Vertical Soft Tissue Augmentation for Severe Hard and Soft Tissue Deficiencies at Malpositioned Implants: A Case Report of a Mucogingival and Restorative Approach.

Clinical efficacy of two vertical soft tissue augmentation techniques for peri-implant crestal bone level stability: A randomized clinical trial.

This study aimed to compare the efficacy of two techniques-acellular dermal matrix (ADM) grafting and tenting technique (TT)-for soft tissue height (STH) augmentation simultaneous to implant placement to minimize peri-implant crestal bone level (CBL) changes. Forty patients with a healed single mandibular posterior edentulous site with a thin soft tissue phenotype were enrolled. Twenty patients received simultaneously to implant placement ADM grafting, while the others received submerged healing abutment (TT). Clinical peri-implant soft tissue height and radiographic CBL changes were measured at restoration delivery and 1-year follow-up. Both techniques effectively increased soft tissue thickness, resulting in a final average STH of 3.4 ± 0.5 mm after augmentation. On average, soft tissue increased by 1.6 ± 0.5 mm in group ADM and by 1.8 ± 0.4 mm in group TT after augmentation. In Group ADM, mesial CBL decreased from 0.4 ± 0.3 mm to 0.1 ± 0.2 mm, and distal CBL decreased from 0.5 ± 0.3 mm to 0.2 ± 0.3 mm over 1 year. In Group TT, mesial CBL remained stable at 0.3 ± 0.2 mm, while distal CBL reduced slightly from 0.5 ± 0.5 mm to 0.3 ± 0.2 mm. Both groups showed minimal changes in CBL, indicating great stability (pmesial = 0.003, pdistal = 0.004). TT was particularly effective in preventing mesial bone loss (pmesial = 0.019). The mesial CBL changes significantly differed between groups (p = 0.019), and not significantly at distal sites (p = 0.944). Neither treatment exhibited significant bone remodeling below the implant shoulder. This study suggests that both techniques were successful in STH augmentation, and they may effectively reduce peri-implant crestal bone level changes, with TT being slightly superior. TT was more prone to post-surgical complications. This RCT was not registered before participant recruitment and randomization.

Effect of Customized and Prefabricated Healing Abutments on Peri-Implant Soft Tissue and Bone in Immediate Implant Sites: A Randomized Controlled Trial

This study aimed to evaluate the effect of customized healing abutments compared to prefabricated healing abutments in immediate implant sites. Twelve patients requiring single immediate implant placement were divided into two groups: a prefabricated group received prefabricated titanium healing abutments, and a customized group received a polyetheretherketone (PEEK) customized healing abutments fabricated based on the individuals’ digital impressions. Outcomes, including peri-implant horizontal and vertical soft tissue alteration, bone level change, volume change, pain score, and pink esthetic score (PES) change, were evaluated at the 1-, 4-, and 6-month follow-ups compared to pre-extraction teeth. At the 1- and 4-month follow-ups, the customized group had a significantly lower buccal volume variation (BVv). At the 6-month follow-up, neither group showed any significant difference in the marginal bone change; however, the customized group had a significantly lower PES change and a lower pain score. In the anterior and premolar regions, the customized group showed the preservation of peri-implant buccal horizontal soft tissue and buccal volume, while in the molar regions, the preservation of papilla height and midfacial height was observed. The morphology of the customized healing abutment demonstrated a better trend in preservation of peri-implant soft tissue, esthetic outcomes, and lower patient discomfort in immediate implant sites.

Palatal Pedicle Connective Tissue for Reconstruction of Through‐and‐Through Soft Tissue Defects in Esthetic Zone Around a Dental Implant: An 8‐Year Follow‐Up Case Report

Soft tissue management for immediate implant placement in the esthetic zone is crucial for successful treatment outcomes. Several surgical and restorative techniques have been proposed to treat unesthetic implant soft tissue defects or dehiscence. However, there is a scarcity of clinical evidence on addressing complications associated with through‐and‐through soft tissue defect (TTSD). In this case, a 61‐year‐old female patient, who underwent immediate implant placement at the right central incisor 3 months prior, presented with chronic peri‐implant mucosal infection and soft tissue recession of TTSD in 2015. The palatal pedicle connective tissue flap (PPCTF) was utilized to provide horizontal and vertical soft tissue augmentation and to cover the defect in combination with the labial contour collapse. At the 8‐year follow‐up, favorable white and pink esthetic outcomes were observed, and the pink esthetic score (PES) for soft tissue around the implant achieved 9 points, indicating satisfactory esthetic and functional results. The findings from this case study suggest that soft tissue augmentation techniques, such as PPCTF grafts, can provide a reliable and innovative method for both soft tissue augmentation and reconstruction of TTSD, resulting in long‐lasting functional and esthetic outcomes and stable ideal PES scores.

The "HAT-TRICK" technique: A modification of soft tissue grafting using volume stable collagen matrix and cross-linked hyaluronic acid. Part A: The pontic site

Vertical soft tissue augmentation between implants can be clinically challenging and burdensome for patients when employing conventional techniques. Recently, with the introduction of xenogenic collagen matrices, the principle of single-site surgery has become more common. However, some issues persist regarding graft stability and tissue integration. In the present technical note, the authors introduce the “HAT-TRICK” technique to address these observed difficulties. As the name suggests, this technique is believed to provide improved stability, volumetric gain, and histological integration of the implanted matrix by shaping it appropriately resembling a hat over the crest with apical bevels, stabilized with fixation pins and infused with cross-linked hyaluronic acid (xHya). A two-month observation of a bi-maxillary case is presented with detailed description of the technique and digitalized comparison methods for an easier explanation of the introduced technique.

Radiographic bone level and soft tissue dimensional changes following explantation of implants affected by peri-implantitis: A retrospective exploratory evaluation.

While the dimensional alteration of alveolar bone following tooth extraction have been extensively descripted in the literature, no information is available regarding potential hard and soft tissues changes following implant explantation. To evaluate the radiographic bone healing and the horizontal and vertical soft tissue dimensional alterations at implant extraction alveoli, 6 months following implant explantation. Data from 31 patients scheduled for extraction of one implant with persisting peri-implantitis despite treatment were analysed. Bone crest level changes and the extent of bone healing at the apical aspect of the implant socket were assessed on the radiographs prior and 6 months following explantation. Regression analyses assessed the impact of various predictors (e.g., bone crest level, presence/absence of buccal bone) on bone level changes. Fisher's exact probability test was applied to assess the difference in probability to have mucosa recession of ≥2 mm in the presence or absence of alveolar buccal bone. A vertical bone loss of 0.8 mm (standard deviation [SD] = 1.3) of the peri-implant bone crest and a gain of 0.8 mm (SD = 1.1) from the bottom of the peri-implant defect were recorded. Complete healing was noted in the intact implant extraction socket (i.e., the part of the implant not affected by peri-implantitis). A reduction of 0.4 mm (SD = 0.7) of the alveolar mucosa height was recorded in concomitant with a decrease of 0.7 mm (SD = 0.8) of the mucosa width. These alterations were more pronounced in the absence of the alveolar buccal bone. The results of the present explorative study indicated a decrease in the height and width of the alveolar soft and hard tissues following explantation of peri-implantitis affected implants, and these changes were more pronounced in the absence of the buccal bone wall. Nevertheless, the apical portion of the implant alveolus (the intact implant socket) tend to heal with no further bone loss.

The bone shielding versus dual-zone concept in treating thin-walled fresh extraction sockets with immediate implant placement: Soft and hard tissue changes. A randomized clinical trial.

To evaluate the ridge alterations and esthetic outcome 1 year after immediate implant placement using the dual-zone (DZ) technique versus the bone shielding concept in patients with intact thin-walled sockets in the esthetic zone. This randomized clinical trial included 26 patients with nonrestorable maxillary teeth in the esthetic zone who were randomly assigned to two groups (n = 13 each) to receive immediate implants using either the bone shielding concept or DZ. Definitive restorations were delivered after 2 months. Pink esthetic scores (PESs), vertical soft tissue alterations, and bucco-palatal ridge dimensional changes were measured and assessed using intra-oral digital scans at baseline and 1 year post-procedure. Labial bone thickness was measured using cone beam computed tomography scans at baseline and after 1 year. The bone shielding group provided bucco-palatal ridge thickness stability after 1 year (9.43 mm) compared to baseline values (9.82 mm), while DZ showed a significant loss in the bucco-palatal ridge thickness after 1 year (7.83) compared to baseline values (9.49). No significant difference was reported in the baseline bucco-palatal ridge thickness between the two groups (p = 0.6). After 1 year, the bone shielding group demonstrated 0.38 mm ridge shrinkage which was statistically significant (p = 0.0002) compared to 1.67 mm ridge shrinkage in the DZ group. In addition, the average total PES in the bone shielding group was 12.04 versus 10.28 in the DZ group. No significant difference was reported in the mesial papilla length between the DZ and the bone shielding group after 1 year (p > 0.05). However, the midfacial gingival margin (p = 0.026) and distal papilla were significantly higher in the DZ group (p = 0.0025). There was no significant difference in the mean ± SD mm bone gain at the apical level between the two studied groups after 1 year (p = 0.06) showing 0.85 ± 0.23 and 0.64 ± 0.32 mm, respectively. However, the bone shielding concept showed a statistically significant more bone gain mm (p < 0.001) at the (0.56 ± 0.43) and crestal (0.03 ± 0.8) levels after 1 year compared to DZ which revealed 0.18 ± 0.5 and 0.38 ± 0.29 mm bone loss, respectively. The bone shielding concept might offer a reliable alternative for restoring thin-walled sockets by minimizing postextraction ridge dimensional alterations effect following immediate implant placement in the esthetic zone. Nevertheless, the study suffers from confounding bias since there are two systematic differences between the groups, the barrier membrane type, and the level of bone filling. "This clinical trial was not registered prior to participant recruitment and randomization." NCT05381467.

Comparative study on the efficacy of gingival retraction using Retraction cord and Expasyl paste in implant patients In-vivo study

Introduction: The precise reproduction of the abutment (implant) provides clinician with crucial clinical information of the relative position and orientation of the implant to other implants, teeth and soft tissue that allow them to fabricate exact- fitting, bio-integrated restoration. For that it is necessary to expose, access &amp; isolate the implant region, especially when cement retained implant prosthesis are in consideration, where conventional crown and bridge impression and optical impression technique is used. Material and Method: Patient who accepted to participate were chosen for the study. Coincidentally all 15 patients were female. They were explained the purpose and methodology, agreed for periodic follow up at the interval of one month after placement of healing abutment and 7 days after using the retraction cord. Conclusion: The conclusions that were drawn from this study are: Both materials showed clinically and statistically significant amount of vertical soft tissue displacement. Among the both soft tissue displacement agents, non-impregnated retraction cord showed the more vertical soft tissue displacement than Expasyl Paste. But, the amount of retraction offered by this paste is limited with extremely subgingival margins. But the advantages with Expasyl paste over the retraction cord were its ease of application, painless, quick, and without agony to the patient.

Radiographic marginal bone level evaluation around two different tissue-level implant systems: a one-year prospective study.

Marginal bone loss, is a frequently reported variable in the evaluation of dental implants. The primary objective of this study was to evaluate radiographic marginal bone level changes around the two different tissue-level implant systems placed adjacently in the posterior maxilla or mandible. The influence of implant macro-geometry and vertical soft tissue thickness on marginal bone loss were also evaluated. Seven patients were included in the study and a total of 18 implants were analyzed. Each patient received two different implants placed adjacently in the maxilla or the mandible. The implants used in our study were either Straumann® SP cylindrical implants or JD Octa® tapered implants. During the surgery, vertical soft-tissue thickness was measured with a periodontal probe placed on the top of the bony crest and in the center of the future implant site. Healing abutments were then seated. Three months following implant placement, impressions were taken, and screw-retained metal ceramic prostheses were delivered. Standardized intraoral radiographs were taken immediately after implant placement and one year following implant loading in order to assess marginal bone level changes. Results showed a mean marginal bone loss of 0.55±0.5 mm for Straumann® SP implants and 0.39±0.49 mm for JD Octa® implants after one year of loading and the difference was not statistically significant between the two systems. A statistically significant correlation was found between soft tissue thickness and marginal bone loss; in sites with thin mucosal tissues (≤2 mm), there was significantly greater bone loss compared to sites with thick, soft tissues (> 2 mm) in both implants. Radiographic marginal bone loss was not statistically different between the two implant systems at the one-year examination period. Moreover, vertical soft tissue thickness influenced marginal bone loss regardless of the implant system used.

Vertical soft tissue augmentation to treat implant esthetic complications: A prospective clinical and volumetric case series.

Challenging implant esthetic complications are often characterized by implant malpositioning and interproximal attachment loss of the adjacent teeth. However, limited evidence is available on the treatment of these conditions. The aim of this study was to evaluate the clinical, volumetric, and patient-reported outcome following treatment of peri-implant soft tissue dehiscences (PSTDs) exhibiting interproximal attachment loss on adjacent teeth, performed through vertical soft tissue augmentation with implant submersion. Ten subjects with isolated PSTD in the anterior maxilla characterized by adjacent dentition exhibiting interproximal attachment loss were consecutively enrolled and treated with horizontal and vertical soft tissue augmentation, involving crown and abutment removal, two connective tissue grafts, and submerge healing. Clinical outcomes of interest included mean PSTD coverage, mean PSTD reduction, clinical attachment level (CAL) gain at the implant and adjacent sites and soft tissue phenotype modifications at 1 year. Optical scanning was used for assessing volumetric changes. Professional assessment of esthetic outcomes was performed using the Implant Dehiscence coverage Esthetic Score (IDES), while patient-reported esthetic assessment involved a 0-10 visual analogue scale. The mean PSTD depth reduction and mean PSTD coverage at 1 year were 2.25 mm, and 85.14%, respectively. A mean keratinized tissue width (KTW) gain of 1.15 mm was observed, while the mean gain in mucosal thickness (MT) was 1.58 mm. A mean CAL gain of 1.45 mm was obtained at the interproximal aspect of the adjacent dentition at 1 year. Greater linear dimensional (LD) changes were observed at the midfacial aspect of the implant compared to the interproximal sites. The mean final IDES was 6.90 points, while patient-reported esthetic evaluation was 8.83 points. The present study demonstrated that vertical soft tissue augmentation with a submerged healing is an effective treatment approach for the treatment of challenging PSTDs with adjacent dentition exhibiting interproximal attachment loss. This technique can be effective in resolution of esthetic complications in most cases, providing a substantial gain in interproximal attachment levels at the adjacent dentition.

Implant Esthetic Complications: Anatomical, Prosthetic, and Patient-Centered Considerations for Treatment.

Implant esthetic complications can negatively affect a patient's perception of implant therapy and their quality of life. This article discusses the etiology, prevalence, and strategies for the treatment of peri-implant soft tissue dehiscences/deficiencies (PSTDs). Three common scenarios of implant esthetic complications were identified and described, in which PSTDs could be managed without removing the crown (scenario I), with the surgical-prosthetic approach (crown removal; scenario II), and/or with the horizontal and vertical soft tissue augmentation and submerged healing (scenario III).

Effect of Acellular Dermal Matrix Placement Simultaneous with Implant Placement on Vertical Soft Tissue Thickness: A Randomized Controlled Clinical Trial.

Acellular dermal matrix (ADM) is commonly used for soft tissue augmentation in root coverage, increasing the width of keratinized gingiva or vestibular depth, or filling the localized alveolar bone defects. This parallel-design randomized controlled clinical trial assessed the effect of ADM membrane placement simultaneous with implant placement on vertical soft tissue thickness. A total of 25 submerged implants were placed in 25 patients (8 men, 17 women) with vertical soft tissue thickness < 3 mm at the surgical site. Patients were randomized into two groups: The intervention group (n = 13) received ADM over the implant for soft tissue augmentation, while no augmentation was performed for the control group (n = 12). After 3 months, healing abutments were placed, and the soft tissue thickness at the surgical site was measured again with a periodontal probe in both groups. Data were analyzed using Mann-Whitney and Wilcoxon tests. All 25 patients were successfully treated. The presurgical vertical soft tissue thickness was 2 mm and 1.92 mm in the control and test groups, respectively (P > .05). These values changed to 1.83 mm and 2.69 mm, respectively, after the intervention. The mean gain in soft tissue thickness was 0.76 mm in the test group, and the difference between groups was statistically significant (P < .05). ADM membrane can be successfully used to augment vertical soft tissue thickness simultaneous with implant placement.

Use of Connective Tissue Graft and Coronally Advanced Flap in Areas of Buccal Contour Concavities for Nonsubmerged Implant Placement.

There is a lack of scientific evidence concerning the best timing of soft tissue management around implants, as well as a divergence of topics concerning optimal procedures. The objective of this study is to evaluate the gain in buccal contour and soft tissue stability after a surgical technique combining nonsubmerged implant placement with submarginal connective tissue graft (CTG) and coronally advanced flap (CAF). Seven patients (4 males and 3 females) underwent surgery for transmucosal implant placement in partially edentulous areas showing mild to moderate buccal contour concavities using a technique combining CTG and CAF. The following parameters were evaluated: keratinized tissue height (KTH), soft tissue thickness (STT), and vertical soft tissue level (VSTL) at T0 (before surgery), T1 (6 months after surgery), T2 (12 months after surgery) and T3 (2 years after surgery). After two years, we observed an increase of 78.5% in buccal KTH, 64% in STT, and 24% in VSTL. No implant presented any sign of mucositis or bone loss. Non-submerged implant placement using an "envelope flap design" in addition to CTG and CAF is beneficial.

Corset trunkoplasty is able to preserve postoperative abdominal skin sensation in massive weight loss patients

Conventional abdominoplasty techniques commonly cause postoperative peri- and infraumbilical skin hypesthesia due to abdominal skin flap undermining. The aim of this study was to evaluate abdominal skin sensation after corset trunkoplasty in massive weight loss patients. Forty-nine massive weight loss patients suffering from excess skin underwent corset trunkoplasty between April 2017 and July 2021. Patient demographics and perioperative complications were recorded. Sensibility of the abdominal skin was measured in three qualities postoperatively using a Semmes-Weinstein monofilament, Tip-Therm® device for thermal sensation and a cotton wooden stick for sharp/blunt discrimination. Results were compared with a control group of healthy individuals to create a baseline. Revision surgery for major complications was necessary in five cases (10%) including hematoma and major wound healing disturbances. Minor complications that did not require surgical intervention were observed in eight cases (16%). Postoperative abdominal sensibility did not show any significant difference between the patient and the control group in all 16 measured areas. Sharp/blunt and thermal discrimination was positive in all patients for the whole abdominal surface area. The corset trunkoplasty technique is able to address both horizontal and vertical soft tissue excess in massive weight loss patients and at the same time limits loss of sensibility of the abdominal skin. Compared to conventional abdominoplasty techniques the abdominal sensation can mainly be preserved due to absence of undermining abdominal skin flaps.

Morphology of Peri-Implant Tissues Around Permanent Prostheses With Various Emergence Angles Following Free Gingival Grafting.

To analyze the tissue morphology around implant-supported prostheses by digital technology and to evaluate the effect of prosthetic contours on the changes in tissues following the free gingiva graft procedure. A total of 53 implants in 32 patients receiving free gingiva grafts were selected. These had previously presented insufficient keratinized mucosa width (KMW). At the follow-up visits (mean: 16.66 ± 9.97 months), the implant position and tissue condition were documented with an oral scanner. Vertical soft tissue thickness (VT), measured from the implant-abutment connection to the marginal tissues, and horizontal soft tissue thickness (HT), at the level of the platform, were calculated. The VT, HT, and emergence angle (EA) of prostheses were assessed by 3Shape analyzing software. The final KMW was measured by clinical assessment. Marginal bone loss (MBL) was calculated in the follow-up bitewing radiographs. The mean VT in the study was 2.65 ± 0.75 mm at the mid-buccal sites, 3.74 ± 1.22 mm at the mesial, 3.16 ± 1.08 mm at the distal, and 2.53 ± 0.92 at the mid-lingual aspects. The mid-buccal HT was 1.45 ± 0.53 mm while the mid-lingual was 1.05 ± 0.43 mm (p = 0.008). Interestingly, prostheses with mid-buccal EA 30° exhibited slightly lower VT, but higher HT, than the ones with EA 30°. Prostheses with proximal EA > 30° displayed slightly more MBL, compared to prostheses with EA 30°. The mean KMW was 4.08 ± 1.10 mm. Free gingival grafting is a predictable treatment approach to augmenting soft tissue 3-dimensionally. Prostheses with EA 30° were preferable for preserving the maximal VT and maintaining crestal bone stability.

The use of the connective tissue graft from the palate for vertical soft tissue augmentation during submerged dental implant placement: A case series.

ObjectivesTo evaluate the efficacy of the soft tissue augmentation vertically, using connective tissue graft from the palate, during submerged dental implant placement.Material and MethodsVertical soft tissue augmentation, using connective tissue graft from the palate, combining with submerged dental implant placement was performed for 50 patients (10 males and 40 females, mean age 57.22 years). Soft tissue thickness vertically was measured in the middle of the alveolar crest with the periodontal probe. After 3 months, healing abutments or multiunits were connected to the dental implants, augmented soft tissue thickness was measured vertically in the middle of the alveolar crest. The vertical soft tissue volume gain was calculated using analysis of variance descriptive analysis, significance set to p = .05.ResultsAll 50 autogenous connective tissue grafts from the palate healed successfully. The average thickness of the soft tissue grafts from the palate was 1.8 ± 0.41 mm. After 3 months, soft tissue thickness vertically increased from 2.27 ± 0.64 mm to 4.35 ± 0.64 mm. This difference between mean figures, between the groups, before and after soft tissue augmentation was found to be statistically significant F (263;477). The mean increase in soft tissue thickness was 2.08 ± 0.71 mm.ConclusionIt can be concluded that soft tissue augmentation vertically, using connective tissue graft from the palate can be successfully used for vertical soft tissue augmentation.

Depth of mucosal tunnel in peri-implant health during 12-month follow-up in patients with controlled periodontitis.

The association between thickness of peri-implant mucosa, known as mucosal tunnel (MT) and related clinical parameters in bone-level implants has not been investigated. Posterior implants, in patients with controlled periodontitis, were evaluated at different time intervals: during uncovering surgery (T0 ), 2-month after uncovering surgery (T2M ) and 12-month after placement (T12M ). Clinical parameters including vertical soft tissue height (VSTH), MT, tooth-implant discrepancy of bone level (DBL), pocket depth (PD), peri-implant marginal bone loss (MBL), emergence profile and emergence angle (EA) were collected, and the correlation were assessed at different time points. Forty-two patients with 60 implants were recruited, and 81.7% of the patients were Stage III-IV, Grade B-C generalized periodontitis. MT presented no significant difference in PD, VSTH, and MBL. Periodontitis Grade C and absence of bone regeneration were significant predictors for deep MT (>3mm), and 5.850 less EA at mesial side of implants (p=0.02).The regression of analysis implied the increase of DBL 1mm would cause 0.26mm deeper MT, 1.7 times higher risk of having deep MT (p=0.041; OR=1.731; 95% CI:1.02-2.93) and 2.1 times higher risk of having circumferential PD>4mm (p=0.019; OR=2.1; 95% CI:1.13-3.92). In bone-level implants, a correlation between MT and clinical parameters at 12-month follow-up was not found. However, history of periodontitis Grade C, absence of bone regeneration and tooth-implant discrepancy of bone level might define the depth of MT. Additionally, the depth of MT played a critical role in determining restorative design.

Clinical and histological evaluation of the use of acellular dermal matrix (ADM) membrane in peri-implant vertical soft tissue augmentation: A controlled clinical trial.

The aim of this study was to clinically and histologically evaluate the efficacy of using acellular dermal matrix (ADM) for peri-implant vertical soft tissue augmentation at implant placement. Twenty patients were enrolled in this study. According to the initial thickness of vertical soft tissue, patients were assigned into the ADM group (≤2mm) or the control group (>2mm) prior to implant surgery +ADM grafting or implant surgery alone. Second-stage surgery was carried out 3months later, and a small piece of ridge membrane was harvested for histological and immunohistochemical evaluation. Vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF)-BB in peri-implant crevicular fluid (PICF) were also assessed 1week, 1month, and 5months after second-stage surgery. Clinical parameters were recorded to evaluate peri-implant health at 1week and 3months after implant restoration. All 20 implants healed uneventfully and successfully. Soft tissue thicknesses were comparable in the two groups at second-stage surgery (3.20±0.42mm vs. 3.50±0.58mm). In the ADM group, the mean increase in soft tissue thickness was 1.85±0.34mm. Histological and immunohistochemical outcomes showed no differences between the two groups. VEGF and PDGF-BB levels in PICF were significantly lower in the ADM group 1week after second-stage surgery (p<.01), yet they decreased in both groups later. The difference between the groups had disappeared by 5months after second-stage surgery. The clinical peri-implant parameters were good and stable by the end of the study (3months after restoration). Our results suggested that using ADM at implant placement was effective in increasing the thickness of peri-implant vertical soft tissue and achieved comparable clinical and histological performance to the control group. However, the incremental soft tissue showed inferior angiogenic ability in the early stage of wound healing.