The effect of platelet-rich fibrin (PRF) versus freeze-dried bone allograft (FDBA) used in alveolar ridge preservation on the peri-implant soft and hard tissues: a randomized clinical trial.

BACKGROUND: The effectiveness of alveolar ridge preservation on bone regeneration and tissue healing has been thoroughly documented in the literature. This study aimed to evaluate the peri-implant soft and hard tissue changes after alveolar ridge preservation using either platelet-rich fibrin (PRF) or freeze-dried bone allograft (FDBA) over a 12-month period following the prosthetic loading of implants. METHODS: In this randomized clinical trial, 40 individuals were recruited for alveolar ridge preservation using (1) FDBA or (2) PRF in incisal/premolar areas. At two follow-up sessions (six- and 12-months post-implant insertion), radiographic imaging and clinical examinations assessed marginal bone loss and soft tissue factors, including gingival recession and bleeding on probing. The differences between study groups were analyzed using Generalized estimating Equations, the Binary logistic regression model, and Cochran's Q test. RESULTS: There was a statistically significant difference regarding gingival recession at both follow-up evaluations; values in the PRF group were considerably lower compared to the FDBA group (p < 0.05). The mean values for vertical marginal bone loss and bleeding on probing showed no significant differences between the two study groups (p > 0.05). CONCLUSIONS: Except for gingival recession, applying PRF yielded comparable clinical results to FDBA after one year of implant loading and could be recommended as a potential biomaterial for alveolar ridge preservation following tooth extractions. CLINICAL TRIAL REGISTRATION: The research protocol was registered in the Protocol Registration and Results System on 13/08/2021, available at https://clinicaltrials.gov/ (NCT05005377).

A multicenter randomized, controlled clinical trial comparing the use of displacement cords, an aluminum chloride paste, and a combination of paste and cords for tissue displacement.

STATEMENT OF PROBLEM: Gingival recession after soft tissue displacement for impression making in fixed prosthodontics may pose a problem for treatment success in the esthetic areas of the mouth. Knowledge about the soft tissue reaction of common gingival displacement methods is limited. PURPOSE: The purpose of this clinical randomized controlled trial (RCT) was to evaluate changes in the marginal soft tissue height with 3 different gingival tissue displacement techniques for definitive impression making of natural teeth. MATERIAL AND METHODS: A total of 67 individuals were randomized to 3 groups. In test group 1 (P; n=22), only aluminum chloride paste was used to displace the gingiva. In test group 2 (CP; n=23), a cord was inserted, and aluminum chloride paste was also used. In the control group (C; n=22), 2 cords were used to displace the gingiva (double-cord technique). Clinical measurements of the gingival position were made before treatment began and at 30 ±10 days after prosthesis delivery. Study casts were fabricated at different stages of the treatment, standardized photographs were made, and changes in the buccal gingival position were measured using graphics editing software. In addition, the participants' perception of the clinical procedure and the technicians' evaluation of the die preparation were recorded. One-way ANOVA models were applied to compare the response variables among the groups: (a) the position of the gingival margin (millimeters), (b) mean probing pocket depth (millimeters), (c) gingival thickness (millimeters), (d) amount of keratinized tissue (millimeters), and (e) mean changes in gingival margin height (millimeters). Unpaired t tests were also used to compare the mean values between groups. For comparisons between different categories, chi-square tests were performed (α=.05 for all tests). RESULTS: In the period between impression and delivery, a minor gain in gingival height of 0.058 mm (±0.13 SD) for P and 0.013 mm (±1.19 SD) for CP. However, a minor gingival recession of 0.049 mm (±0.13 SD) was reported for group C. The results for all groups showed that 21% of abutment teeth gained >0.1 mm in gingival height, 58% had stable gingival height (0 ±0.10 mm), 21% showed minor gingival recession (0.1 to 0.5 mm), and no abutment teeth showed moderate or severe gingival recession (>0.5 mm). The incidence of minor gingival recession was 8% in group P, 23% in group CP, and 32% in group C (P=.015). Fifteen participants (24%) experienced some discomfort after the procedure. The differences between the groups were not significant (P>.05). The laboratory technicians found the definitive die preparation significantly more challenging for group P (visual analog scale [VAS], 79) and CP (VAS, 82) than group C (mean VAS, 93; P=.003). CONCLUSIONS: Minor or moderate gingival recession (<1 mm) is more likely to occur when conventional cords are used during impression making. However, the laboratory technicians found the die preparation significantly less challenging when the double-cord technique was used than when impressions were made using the paste displacement technique.

Implant placement post extraction in esthetic single tooth sites: when immediate, when early, when late?

Implant placement in post-extraction sites of single teeth in the esthetic zone has been a topic of great interest in the field of implant dentistry since 1990. Triggered by the development of guided bone regeneration, the concept of immediate implant placement became quite popular in the 1990s. In the past 12 years, however, the dental community has begun to focus increasingly on the esthetic outcomes of post-extraction implant placement and several studies indicated a significant risk for the development of mucosal recessions with immediate implants. Parallel with this, significant progress has been made in the understanding of tissue biology in terms of hard and soft tissue alterations post extraction, based on preclinical, clinical and radiological studies. This knowledge has helped better to understand the etiology of these esthetic complications with immediate implant placement. The present review first analyzes the various phases of the development of therapeutic strategies over the years for post-extraction implant placement in single tooth sites in the esthetic zone. It presents the current knowledge concerning the terminology with immediate, early and late implant placement, the risk factors for the development of esthetic complications, and the selection criteria for the various treatment options. In the second part, clinical recommendations are given, since a clinician active in this field of implant therapy can use all treatment options depending on the preoperative analysis including a 3D cone beam computed tomography. The selection criteria for all four treatment options are presented and documented with typical case reports to illustrate the current treatment approaches applied in daily practice.

Bristle splaying and its effect on pre-existing gingival recession-a 12-month randomized controlled trial.

OBJECTIVE: The link between bristle splaying and gingival recession is unclear. METHODS: In a 12-month, parallel group, randomized, controlled clinical trial, 110 systemically healthy participants with pre-existing gingival recessions (pre-GR) were assigned to brush their teeth with either a manual (MT) or a powered toothbrush (PT). Every 3 months, toothbrushes and brush heads were replaced. Wear was measured using the Bristle-Splaying-Index (BSI), matched between groups and correlated to the change of pre-GR. RESULTS: Data from 109 subjects (PT, 55; MT, 54) were analyzed. The overall mean BSI was found to be significantly lower (p < 0.001) in the PT group (median 5.5; second and third quartile 1.9-10.0) as compared to the MT group (21.5; 15.0-30.5). After 12 months, pre-GR decreased significantly in the PT group (∆0.2 ± 0.1 mm; p < 0.001) and remained stable in the MT group (∆0.1 ± 0.1 mm; p > 0.05). In the MT group, higher BSI values were associated with a higher risk for increasing or stable recession over 12 months: odds ratio (95 % CI) = 27.9 (1.7; 452.9); p = 0.019. CONCLUSION: After a mean using time of 3 months, the PT group demonstrated a lower BSI than the MT group, and the greater bristle splaying was associated with a higher risk of increased (or stable) GR in subjects using a MT but not a PT. CLINICAL RELEVANCE: Compared to a manual toothbrush, powered toothbrushes seem to be utilized with less force and can be considered safe to use in patients with pre-existing gingival recession.

Management and prevention of gingival recession.

Gingival recession is highly prevalent worldwide. It increases the risk for root caries and can interfere with patient comfort, function and esthetics. Progressive gingival recession also increases the risk of tooth loss secondary to clinical attachment loss. Although mitigating the causes of gingival recession decreases its incidence and severity, implementing practical management and prevention strategies in the clinical setting can be challenging. Identification of susceptible patients and evaluating them for the presence of modifiable risk exposures are essential first steps in developing action plans for appropriate interventions. This article reviews these steps and introduces chairside tools that can help in the selection of interventions designed to reduce the risk of future gingival recession and may also facilitate patient communication. Practical decision-making criteria are proposed for when and how to monitor gingival recession, for deciding when a patient is a candidate for surgical evaluation or referral to a periodontist, and, if surgery is the treatment of choice, what should be considered as key surgical outcome objectives.

Maintaining Osseointegration: Understanding, preventing, and treating Risk Factors for Peri-implant Diseases.

The dental implant is a predictable way of restoring fully and partially edentulous patients and has shown high success rate for managing a broad range of clinical conditions. Improving implant surfaces has revolutionized the osseointegration of implants and changed the focus of implant research from osseointegration more toward the risk factors associated with the failure of implants in the long-term.

Primary and secondary prevention of periodontal and peri-implant diseases: Introduction to, and objectives of the 11th European Workshop on Periodontology consensus conference.

BACKGROUND: Periodontitis prevalence remains high. Peri-implantitis is an emerging public health issue. Such a high burden of disease and its social, oral and systemic consequences are compelling reasons for increased attention towards prevention for individuals, professionals and public health officials. METHODS: Sixteen systematic reviews and meta-reviews formed the basis for workshop discussions. Deliberations resulted in four consensus reports. RESULTS: This workshop calls for renewed emphasis on the prevention of periodontitis and peri-implantitis. A critical element is the recognition that prevention needs to be tailored to the individual's needs through diagnosis and risk profiling. Discussions identified critical aspects that may help in the large-scale implementation of preventive programs: (i) a need to communicate to the public the critical importance of gingival bleeding as an early sign of disease, (ii) the need for universal implementation of periodontal screening by the oral health care team, (iii) the role of the oral health team in health promotion and primary and secondary prevention, (iv) understanding the limitations of self-medication with oral health care products without a diagnosis of the underlying condition, and (v) access to appropriate and effective professional preventive care. CONCLUSIONS: The workshop provided specific recommendations for individuals, the oral health team and public health officials. Their implementation in different countries requires adaptation to respective specific national oral health care models.

[Gingival recessions and orthodontics]. / Gingivarecessies en orthodontie.

Gingival recessions represent the most visible periodontal disease. The prevalence of gingival recessions is high. The root surface is literally exposed to negative influences such as erosion, abrasion, discoloration and decay. Moreover, gingival recessions can affect the quality of life by increased thermal sensitivity and reduced dento-gingival aesthetics. The aetiology of gingival recessions is complex and considered to be multifactorial. In order to prevent the development of gingival recessions during and after orthodontic treatment, several factors should be taken into account, among which maintenance of optimal oral hygiene and respect for the 'biological envelope' are decisive. Once gingival recessions have developed, orthodontic therapy can play a positive role in their treatment.

Combined surgical therapy of advanced peri-implantitis lesions with concomitant soft tissue volume augmentation. A case series.

OBJECTIVES: Mucosal recessions are a common finding following surgical treatment of peri-implantitis, thus compromising the overall esthetic outcome of implant therapy. This case series aimed at evaluating the clinical outcome of a combined surgical therapy of advanced peri-implantitis lesions with concomitant soft tissue volume augmentation. MATERIAL AND METHODS: Ten patients (n = 13 implants exhibiting combined supra- and intrabony defects) underwent access flap surgery, implantoplasty at bucally and supracrestally exposed implant parts, and augmentation of the intrabony components using a natural bone mineral and a native collagen membrane after surface decontamination. A subepithelial connective tissue graft was harvested from the palate and adapted to the wound area to support transmucosal healing. Clinical parameters (i.e. bleeding on probing--BOP; probing depths--PD; mucosal recession--MR; clinical attachment level--CAL) were recorded at baseline and after 6 months. RESULTS: At 6 months, the combined surgical procedure was associated with a significant reduction in mean BOP (74.39 ± 28.52%), PD (2.53 ± 1.80 mm), and CAL (2.07 ± 1.93 mm) values. Site-level analysis has pointed to a slight increase in mean mucosal height (0.07 ± 0.5 mm) at the buccal aspects (i.e. mb, b, db). CONCLUSION: The combined surgical procedure investigated may be effective in controlling advanced peri-implantitis lesions without compromising the overall esthetic outcome in the short term.

Periodontal dressing after surgical crown lengthening: a randomized clinical trial.

OBJECTIVE: The aim of the present study was to evaluate the effect of periodontal dressing on post-operative pain and swelling after surgical crown lengthening. MATERIALS AND METHODS: A blind, randomized, clinical trial was carried out with 36 patients. Following surgical crown lengthening, the individuals were randomly allocated to the periodontal dressing group (PDG) and control group (CG, non-placement of periodontal dressing). Pain and discomfort were analyzed using a visual analog scale (VAS), verbal scale (VS) and the number of analgesics consumed in 7 days post-operatively. Post-operative infection, stability of the gingival margin and type of healing were also evaluated. RESULTS: The PDG had a significantly higher percentage of responses of 'strong pain' on the VS in the first day post-operatively (33.3% vs 5.3%, p = 0.03) and greater pain on the first and second days post-operatively based on the VAS. Moreover, a significant difference between groups was found regarding gingival swelling after 7 days. However, gingival recession was found in 57.8% of the sites in the CG and only 5.5% of sites in the PDG. No change in condition was found among individuals with conjunctive tissue/bone exposure in the CG in the immediate post-operative period and 80% of the patients in the PDG had healing by first intention after 7 days. CONCLUSION: The use of periodontal dressing seems to be preferable following surgical crown lengthening with connective tissue/bone exposure. However, adequate post-operative analgesic strategies should be employed due to the possibility of intense pain in the first 24 hours.

Platform switching and abutment emergence profile modification on peri-implant soft tissue.

Although the peri-implant hard tissue advantages of platform switching abutments have been well documented by many authors, the peri-implant soft tissue advantages of platform switching abutments has had limited mention. This article illustrates how the amount of peri-implant soft tissue volume is influenced by the dimensional extent of platform switching and the degree that an abutment's sulcular emergence profile has been modified. This article also introduces the term "abutment sulcular emergence profile enhancement" (ASEPE) to describe the combined effect of platform switching and abutment emergence profile modification. Three unrecognized clinical advantages of ASEPE are described by different clinical cases. First, elimination of excessive abutment impingement on gingival tissue adjacent to implants is achieved. Second, allowance for sufficient interproximal space between implant and adjacent tooth/implant for the entry of interproximal toothbrush is made possible. Third, excessive soft tissue blanching during abutment seating at prosthesis delivery is eliminated. Together, the combined application of platform switching and abutment emergence profile modification represents the opening of a new realm for managing soft tissue around implants to resolve dimensional problems.

[Method for prevention of tissue atrophy after teeth extraction].

Modern approach to teeth loss treatment anticipates two main goals - both functional and esthetic rehabilitation. Smile esthetic depends not only on teeth shape, size and color but also on gingival volume and position (pink esthetic). The paper describes the method of optimal tissue preservation after frontal teeth extraction including free tissue transfer in the site of extraction performed in 24 patients. Palatal free autograft was positioned to refill the defect and sutured to gingival margin. Sutured were removed in 7 days. The method proved to be efficient and may be recommended for use in in-patient oral surgery units.

The biologically oriented preparation technique (BOPT) approach for preventing gingival recessions in fixed prosthodontics. A 5- to 13-year follow-up retrospective study.

AIM: The present study was a retrospective medium- to long-term follow-up assessment of the clinical outcomes of patients rehabilitated with fixed prostheses according to the biologically oriented preparation technique (BOPT) principles. MATERIALS AND METHODS: Clinical records of patients rehabilitated between January 2007 and December 2014 were retrospectively assessed. Patients whose records met the inclusion criteria were also recalled for a hygiene visit. Data analyzed included the patients' periodontal condition, the presence of gingival recessions as well as any technical or biologic prosthetic complication. RESULTS: Fifty-eight patients were recalled; of these, 52 patients who had received 220 crowns were available for the evaluation (the dropout being 13.8%). The average follow-up was 9.3 years (range 5 to 13 years): 14 patients (114 prosthetic crowns) had a follow-up between 5 and 8 years, and 36 patients (106 prosthetic crowns) between 9 and 13 years. The prosthetic survival rate was 99.6%. One radicular fracture (0.4%) and four chippings of the veneering porcelain (1.8%) were recorded. Six teeth (2.7% of the examined prosthetic crowns) presented gingival recession of < 1 mm, and 13 teeth (24 sites) had a pocket probing depth of 4 mm (5.9% of the prosthetic crowns/1.8% of the sites). Finally, 20 sites (1.5%) in seven teeth (3.2%) showed bleeding on probing. CONCLUSIONS: Tooth preparation according to the BOPT principles (ie, with a vertical finishing line) resulted in medium- to long-term periodontal health and stability of the gingival tissue, and prosthetic success was maintained.

Efficacy of modified minimally invasive surgical technique in the treatment of human intrabony defects with or without use of rhPDGF-BB gel: a randomized controlled trial.

AIM: To evaluate the efficacy of modified minimally invasive surgical technique (M-MIST) technique with local delivery of recombinant human platelet derived growth factor (rhPDGF-BB) gel in the treatment of intrabony defects. MATERIAL AND METHODS: Twenty-four healthy subjects were included in the present double-blinded, randomized, controlled study. Test group was treated with M-MIST and rhPDGF-BB and control group with M-MIST alone. RESULTS: The mean probing depth (PD), clinical attachment level (CAL) and gingival recession, cementoenamel junction to base of the defect (CEJ-BD), defect depth (DD) and cementoenamel junction to alveolar crest (CEJ-AC), at baseline to 6 months post-operatively in both the groups were statistically significant. Inter-group comparison for gain in attachment level (CAL-G), probing depth reduction (PD-R) and change in gingival margin position linear bone growth (LBG), percentage bone fill, residual defect depth (residual DD) and the change in alveolar crest position revealed no statistically significant differences. Gain in CAL and LBG was 3 ± 0.89 mm and 1.89 ± 0.6 in test group and 2.64 ± 0.67 mm and 1.85 ± 1.18 mm in control group, respectively, and did not show statistical significance. CONCLUSIONS: The improvement in both groups could be attributed to the novel surgical technique rather than addition of rhPDGF-BB.

Longitudinal supportive periodontal therapy for severe chronic periodontitis with furcation involvement: a 12-year follow-up report.

We report a case involving a 12-year follow-up after treatment for chronic periodontitis with furcation involvement. A 54-year-old woman presented with the chief complaint of hypersensitivity. Clinical examination at the first visit revealed 15% of sites with a probing depth ≥4 mm and 35% of sites with bleeding on probing. Initial periodontal therapy was implemented based on a clinical diagnosis of severe chronic periodontitis. Surgical periodontal therapy was subsequently performed at selected sites. For #44, regenerative periodontal therapy using enamel matrix derivative (Emdogain(®)) was selected. For #16, which exhibited a 2- to 3-wall vertical bony defect and class III (mesio-distal) furcation involvement, bone graft was scheduled. Other sites with residual periodontal pockets were treated by open flap debridement. For #37, with a gutter-shaped root, odontoplasty was performed. After reevaluation, the patient was placed on supportive periodontal therapy (SPT). During 12 years of SPT, the periodontal condition remained uneventful in most of the teeth. However, bone resorption was observed in the distal aspect of #37, making the prognosis poor. This indicates the need to continuously monitor risk factors, including inflammation and traumatic occlusion, during SPT. Although some problems still remain, severe periodontitis with furcation involvement was successfully maintained longitudinally with an adequate level of patient compliance and careful SPT.

Predictors of inter-proximal and midfacial recession following single implant treatment in the anterior maxilla: a multivariate analysis.

PURPOSE: A number of factors have been associated with soft tissue recession following single implant treatment. However, given the cross-sectional design of most of these studies and crude associations based on univariate analyses, such factors may only be considered risk indicators. The objective of the present retrospective cohort study using multivariate analyses was to identify predictors of recession. MATERIAL AND METHODS: Patients who had been treated by two periodontists and two prosthodontists in 2006 and 2007 for a single implant in the anterior maxilla were re-examined in 2009 and their records were scrutinized. Subjects treated via flap surgery with and without ridge re-contouring were considered. Outcome variables were inter-proximal and midfacial recession. Explanatory variables included demographic data, the surgical approach and a number of local factors that were evaluated on radiographs taken pre-operatively or at permanent crown installation (baseline). RESULTS: Data pertaining to 97/115 (60 females, 37 males; mean age 51, SD 13, range 23-80) patients were available for evaluation. Significant bone loss was observed between baseline and re-examination at the implant surface (0.2-0.3 mm, p < 0.001) and tooth surface (0.3-0.5 mm, p < 0.001). Surgery with ridge re-contouring demonstrated 0.2 mm additional bone loss at the distal tooth surface when compared to surgery without ridge re-contouring (p = 0.034). This could be explained by a disparity in possible papilla-opening procedures (three versus one or two). As a result, regression analyses identified surgery with ridge re-contouring as a predictor of inter-proximal recession (OR ≥ 3.4). Pre-operative bone level at the tooth surface was another predictor of inter-proximal recession (OR ≥ 2.1). Recession of the distal papilla was also affected by a missing contact point (OR = 221.9), the implant-to-tooth distance (OR = 0.3) and the distance of the bone peak to the contact point (OR = 2.9). Midfacial recession was only associated with a buccal shoulder position (OR = 17.2). CONCLUSIONS: To optimize soft tissue levels around single implants, clinicians should limit papilla-opening procedures and pay utmost attention to a correct implant and contact point positioning.

Regenerative periodontal therapy of infrabony defects using minimally invasive surgery and a collagen-enriched bovine-derived xenograft: a 1-year prospective study on clinical and aesthetic outcome.

AIM: To evaluate the clinical and aesthetic outcome of regenerative periodontal therapy (RPT) using minimally invasive surgery and a collagen-enriched bovine-derived xenograft (1); to identify risk factors for failure (clinical attachment level (CAL) gain ≤ 1 mm) and advanced gingival recession (REC) increase (>1 mm) (2). MATERIAL AND METHODS: Ninety-five non-smoking patients, with ≤ 25% full-mouth plaque and bleeding presenting ≥ 6 months after initial periodontal therapy with ≥ 1 isolated inter-dental infrabony defect were recruited. Patients were consecutively treated by the same clinician using minimally invasive surgery and a collagen-enriched bovine-derived xenograft. Clinical, radiographic and aesthetic data were collected before surgery and up to 1 year. Multivariate analyses were used to identify risk factors for failure and advanced REC increase. RESULTS: Eighty-four patients (39 men, 45 women; mean age 53) complied and demonstrated mean probing depth (PD) of 7.8 mm, CAL of 10.0 mm and defect depth of 5.2 mm before surgery. At 1 year, postsurgery mean PD reduction was 3.5 mm (range 0.0-8.0), CAL gain was 3.1 mm (range 0.0-7.0) and radiographic defect fill was 53% (range 0-100). Forty-nine percentage showed ≥ 4 mm CAL gain, whereas 15% were considered failures. Mean inter-dental and midfacial REC increase was 0.3 mm (range-2.0-2.0) and 0.5 mm (range-1.5-2.0) respectively. Midfacial REC increase and contour deterioration contributed most to a small, yet significant reduction in the Pink Esthetic Score from 10.06 to 9.42 (p = 0.002). Risk factors for failure included defects with a non-supportive anatomy (OR: ≥ 10.4), plaque (OR: 14.7) and complication(s) (OR: 12.0). Risk factors for advanced midfacial REC increase included defects with a non-supportive anatomy (OR: 58.8) and a thin-scalloped gingival biotype (OR: 76.9). CONCLUSIONS: RPT using minimally invasive surgery and a collagen-enriched bovine-derived xenograft demonstrated favourable clinical outcome after 1 year, even though soft tissue aesthetics could not be fully preserved. Defects with a non-supporting anatomy may be at risk for failure and advanced midfacial recession.

Is there a need for keratinized mucosa around implants to maintain health and tissue stability?

AIM: The objective of the present review was to analyze the literature with regard to the need for keratinized mucosa around implants to maintain health and tissue stability. METHODS: Human and animal studies were identified through electronic and hand searches. Predetermined outcome measures were (i) implant loss, (ii) peri-implant health, (iii) oral hygiene, (iv) soft-tissue recession, (v) change in marginal bone level, and (vi) patient-centered outcomes. With respect to outcome variables, change in "attachment level", soft-tissue recession and change in peri-implant bone level were only retrieved from longitudinal studies. For remaining parameters, cross-sectional studies were also considered. RESULTS: Nineteen relevant publications were identified (17 human and 2 animal studies). Due to marked heterogeneity in study design and reported data, no statistical analysis of retrieved data was feasible. Twelve human studies reported plaque scores for sites with "adequate" (≥2 mm) and "inadequate" (<2 mm) width of keratinized mucosa, and in five studies, an "inadequate" width was associated with a significant higher plaque score. Half of the studies showed significantly higher bleeding scores at implants with < 2 mm of keratinized mucosa, while the majority of publications (8 of 10) found no differences for probing depths. Two of three longitudinal studies reporting on recessions described no long-term differences with regard to the amount of keratinized mucosa. Evidence on the effect of keratinized mucosa on bone-level changes or implant loss was scarce, and no conclusions could be drawn. No article reporting patient-centered outcomes could be identified. CONCLUSION: Collectively, the findings of this review show that evidence in support of the need for keratinized tissues around implants to maintain health and tissue stability is limited.

Clinical efficacy of a xenogeneic collagen matrix in augmenting keratinized mucosa around implants: a randomized controlled prospective clinical trial.

AIM: The aim of this controlled randomized clinical trial was to evaluate the efficacy of a xenogeneic collagen matrix (CM) to augment the keratinized tissue around implants supporting prosthetic restorations at 6 months when compared with the standard treatment, the connective tissue autograft, CTG). MATERIALS AND METHODS: This randomized longitudinal parallel controlled clinical trial studied 24 patients with at least one location with minimal keratinized tissue (≤1 mm). MAIN OUTCOME MEASURE: The 6-month width of keratinized tissue. As secondary outcomes the esthetic outlook, the maintenance of peri-implant mucosal health and the patient morbidity were assessed pre-operatively and 1, 3, and 6 months post-operatively. RESULTS: At 6 months, Group CTG attained a mean width of keratinized tissue of 2.75 (1.5) mm, while the corresponding figure in Group CM was 2.8 (0.4) mm, the inter-group differences not being statistically significant. The surgical procedure in both groups did not alter significantly the mucosal health in the affected abutments. There was a similar esthetic result and significant increase in the vestibular depth in both groups as a result of the surgery. In the CM group it changed from 2.2 (3.3) to 5.1 (2.5) mm at 6 months. The patients treated with the CM referred less pain, needed less pain medication, and the surgical time was shorter, although these differences were not statistically significant when compared with the CTG group. CONCLUSIONS: These results prove that this new CM was as effective and predictable as the CTG for attaining a band of keratinized tissue.