The Association Between Buccal Mucosa Thickness and Periimplant Bone Loss and Attachment Loss: A Cross-Sectional Study

Association of Peri-Implant Keratinized Mucosa Width and Mucosal Thickness with Early Bone Loss: A Cross-Sectional Study

Objective: The objective of this study was to evaluate the effects of keratinized mucosa width (KMW) and mucosal thickness (MT) around dental implants on marginal bone loss (MBL). The evaluation was performed one year after loading by comparing clinical, radiographic, and biochemical parameters. Methods: The study included 87 implants in 87 patients undergoing regular follow-ups without hard or soft tissue augmentation one year after loading. Clinical measurements included plaque index (PI), gingival index (GI), bleeding on probing (BoP), probing depth (PD), KMW, and MT. MBL was assessed with periapical radiography. The peri-implant crevicular fluid (PICF) was analyzed for tumor necrosis factor-alpha (TNF-α), receptor activator of nuclear factor-kB ligand (RANKL), osteoprotegerin (OPG), and microRNA-27a. Results: The MBL of implants with thin MT (<2 mm) was higher than that of implants with thick MT (≥2 mm) (p < 0.05). A significant negative correlation (r: -0.217) was established between MT and MBL. No significant association was found between KMW and MBL (p > 0.05). No significant associations was found between KMW and MT with TNF-α, RANKL, OPG and RANKL/OPG (p > 0.05), with the exception of increased microRNA-27a levels in implants with KMW ≥ 2 mm (p < 0.05). Conclusions: Implants with a thick MT had a lower MBL. There may be an association between adequate KMW and high miRNA-27a levels. The relationship between MBL and miRNA-27a remains unclear.

Maxillary labial peri-implant hard and soft tissue alteration observed on cross-sectional dimension: a 2-year prospective observational study

OBJECTIVES

To evaluate how peri-implant hard and soft tissue height (BH, MH) alter after final prostheses placement related to labial hard and soft tissue thickness (BW, MW).

MATERIALS AND METHODS

Forty-five platform-switched implants were classified into four groups according to BW and MW: type 1 (thick BW and thick MW), type 2 (thick BW and thin MW), type 3 (thin BW and thick MW), type 4 (thin BW and thin MW). Tissue resorption was evaluated on cone-beam CT images taken at final prostheses placement, at 1-year follow-up, and at 2-year follow-up. Kruskal-Wallis test and post hoc Mann-Whitney test were applied; significance was set to 0.05.

RESULTS

BH resorption was 0.13 ± 0.12 mm in type 1, 0.26 ± 0.17 mm in type 2, 0.09 ± 0.09 mm in type 3, 0.94 ± 0.19 mm in type 4. Differences between type 1 and 4, type 2 and 4, and type 3 and 4 were statistically significant (p < 0.001, p = 0.005, p < 0.001, respectively). MH resorption was 0.10 ± 0.09 mm in type 1, 0.36 ± 0.16 mm in type 2, 0.12 ± 0.12 mm in Type 3, 0.79 ± 0.23 mm in type 4. Differences between type 1 and 2, type 1 and 4, type 2 and 3, type 2 and 4 and type 3 and 4 were statistically significant (p < 0.001).

CONCLUSIONS

Significantly less BH/MH resorption occurs around implants with thick BW/MW than those with thin BW/MW in 2 years. Implants with thick peri-implant soft tissue resulted in significantly less tissue resorption in second year after final prostheses placement.

Full-Arch Guided Restoration and Bone Regeneration: A Complete Digital Workflow Case Report

OBJECTIVE

complex rehabilitations present multiple difficulties, regarding both the planification of the surgery and the design of the prothesis. A digital approach can support the workflow, as well as the degree of intraoperative precision, and improve the long-term prognosis.

METHODS

A surgical guide was designed for implant placement. An extensive regeneration of the upper jaw was performed with contextual implant insertion, and a delayed load rehabilitation was chosen. After four months, a second surgery and a simultaneous soft tissue augmentation was performed, and a 3D-printed temporary restoration was placed. After another two months, new dental and facial scans, smile design, and facial bite registrations were obtained. Upper and lower dentures were built using an exclusively digital workflow. Both metal substructures were passivated and cemented in one session; in the following appointment, the aesthetic and occlusal checks were carried out. During the third visit, both prostheses were delivered.

RESULTS

Careful case planning and the surgical guide made it possible to achieve primary stability and acceptable emergence profiles in an extremely reabsorbed upper jaw. Leukocyte-Platelet Rich Fibrin (L-PRF) made the extensive bone regeneration more approachable and lowered the post-operative pain and swelling, while speeding up the soft tissue healing process. During the re-entry surgery, the volumes of soft tissues were increased to improve aesthetics, and the amount of keratinized gingiva around the six implants was also increased. Smile design and facial scans have provided the means to create acceptable aesthetics and function in a few sessions with minimal patient discomfort.

CONCLUSIONS

Computer-assisted implantology is a safe and precise method of performing dental implant surgery. Preliminary studies have a high degree of accuracy, but further studies are needed to arrive at a fully digital clinical protocol at all stages.

Evaluation of esthetic outcome of delayed implants with de-epithelialized free gingival graft in thin gingival phenotype with or without immediate temporization: a randomized clinical trial

AIM

The current study investigates the effect of immediate temporization on the pink esthetics of delayed implants in patients with thin gingival phenotype in combination with a De-epithelialized Free Gingival Graft in the maxillary premolar area.

METHODOLOGY

The study population was randomly assigned into two groups. The two groups were treated with delayed implants with simultaneous placement of a de-epithelialized free gingiva graft. The test group was immediately temporized while the control group had no temporization. The pink esthetic score was assessed as the primary outcome. Additional secondary outcomes were assessed such as the keratinized tissue width and the soft tissue thickness.

RESULTS

Twenty implants were placed in the current study, split into 10 implants per group. The results showed that the Pink Esthetic Score of the IT group was 11.88 ± (1.13) and 11.33 ± (1.25) for the CTG group, which showed no statistical difference between the groups after 1 year of follow-up. There was also no significant difference between the two groups at 12 months regarding the keratinized tissue width and the soft tissue thickness.

CONCLUSIONS

Immediate and delayed temporizations have no effect on the Pink Esthetics of the delayed implants; however, immediate temporization allowed earlier provisional crown delivery. Soft tissue augmentation of the thin gingival phenotype improved esthetics for both groups. Trial registration Name of the registry: clinicaltrials.gov; trial registration number: NCT03792425. Date of registration: January 3, 2019. URL of trial registry record: https://clinicaltrials.gov/ct2/show/NCT03792425?term=NCT03792425&draw=2&rank=1.

Impact of peri-implant soft tissue characteristics on health and esthetics

OBJECTIVE

To review the impact of key peri-implant soft tissue characteristics on health and esthetics.

MAIN CONSIDERATIONS

The keratinized mucosa width (KMW), the mucosal thickness (MT), and the supracrestal tissue height (STH) are essential components of the peri-implant soft tissue phenotype. An inadequate KMW (<2 mm) has been associated with local discomfort upon oral hygiene performance and increased risk for the onset of peri-implant diseases. A minimum buccal MT (≥2 mm) is generally required to prevent esthetic issues related to the effect of transmucosal prosthetic elements on the color of the mucosa and can also contribute to long-term mucosal stability. STH is directly related to marginal bone remodeling patterns during the early healing process that follows the connection of transmucosal prosthetic components. Short STH, generally defined as <3 mm, has been consistently associated with marginal bone loss resulting from the physiologic establishment of the mucosal seal. Insufficient STH may also derive into the fabrication of unfavorable transmucosal prosthetic contours, which frequently results in unpleasing esthetic outcomes and predisposes to submarginal biofilm accumulation. Peri-implant soft tissue dehiscences (PISTDs) are a type of peri-implant deformity that are associated with esthetic issues and often occur in sites presenting KMW, MT, and/or STH deficiencies. PISTDs should be correctly diagnosed and treated accordingly, usually by means of multidisciplinary therapy.

CONCLUSION

Understanding the impact of different dimensional and morphologic features of the peri-implant mucosa on health and esthetic outcomes is fundamental to make appropriate clinical decisions in the context of tooth replacement therapy with implant-supported prostheses.

Palatal soft tissue thickness around dental implants and natural teeth in health and disease: A cross sectional study

BACKGROUND

Previous studies focused on the influence of buccal mucosa thickness on peri-implant bone loss and inflammation, with inconclusive results. We observed substantially thicker palatal mucosal tissues at peri-implantitis sites. Therefore, we hypothesize that thick palatal peri-implant mucosa may be associated with deeper pockets and disease severity.

PURPOSE

To compare the thickness of the palatal tissue between natural teeth and implants in periodontal health and disease.

METHODS

Adult, non-smoker, healthy patients who visited our department for periodontal examination or treatment with restored implants in the posterior maxilla were recruited. Probing depth (PD), plaque index (PI), gingival index (GI) and radiographic measurements were recorded around implant and the contralateral tooth. Palatal tissue thickness was measured using a 30G needle that was inserted perpendicular into the mucosa at the bottom of the periodontal/peri-implant pocket and 3 mm coronally. Differences in the palatal tissue thickness between teeth and implants (in the same patient) was performed using t-test; as well as between peri-implantitis and non-peri-implantitis sites (among patients).

RESULTS

Sixty patients were included. Thirty-four implants were diagnosed with peri-implantitis and 26 healthy/mucositis implants with corresponding 24 healthy/gingivitis teeth and 36 teeth with attachment loss. Mean PD was higher around implants (4.47 ± 1.57 mm) than teeth (3.61 ± 1.23 mm, p = 0.001). The thickness of implants' palatal mucosa was higher than in teeth, at the base of the pocket and 3 mm coronally (4.58 ± 1.38 mm vs. 3.01 ± 1.11, p = 0.000; 3.58 ± 2.15 vs. 1.89 ± 1.11, p = 0.000, respectively). Mean palatal tissue thickness was 4.32 ± 2.35 mm for the peri-implantitis group while only 2.61 ± 1.39 in healthy implants, 3 mm coronal to the base of the pocket (p = 0.001). Palatal thickness at peri-implantitis sites was higher (4.32 ± 2.35) compared to periodontitis sites (2.23 ± 0.93), p = 0.000. Implant sites with palatal mucosa >4 mm (n = 32) had deeper mean pockets (5.58 ± 1.98) compared with thinner (≤4 mm) sites (n = 28) (4.48 ± 1.18, p = 0.018).

CONCLUSION

Thicker palatal tissue around implants is associated with deeper palatal pockets. Thick palatal tissue was found around implants diagnosed with peri-implantitis.

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.

The influence of thin as compared to thick peri-implant soft tissues on aesthetic outcomes: A systematic review and meta-analysis

Objectives

In 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)?

Methods

Following 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.

Results

Thirty‐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.

Conclusion

Within 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.

Effect of peri-implant mucosal thickness on esthetic outcomes and the efficacy of soft tissue augmentation procedures: Consensus report of group 2 of the SEPA/DGI/OF workshop

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.

Prevalence and risk indicators of midfacial peri-implant soft tissue dehiscence at single site in the esthetic zone: A cross-sectional clinical and ultrasonographic study

BACKGROUND

Esthetic complications of dental implants in the esthetic zone can have a major negative impact on patients' quality of life and perception of implant therapy. The aim of the present study was to evaluate the prevalence of peri-implant soft tissue dehiscence (PSTD) and the clinical and ultrasonographic risk indicators for this condition.

METHODS

Subjects with one or more healthy single dental implants in the esthetic area were identified and recruited. Clinical and ultrasonographic measurements, including PSTD class and subclass, pocket depth, keratinized mucosa width (KMW), mucosal thickness (MT) at 1 mm and 3 mm, buccal bone distance (BBD) and buccal bone thickness, were evaluated in healthy implants and implants with PSTD.

RESULTS

153 subjects with a total of 176 dental implants were included. The prevalence of PSTD was 54.2% and 56.8% on a patient and implant level, respectively. The most frequent type of PSTD was the one characterized by having both an implant-supported crown longer than the clinical crown of the homologous tooth and a visible abutment/implant fixture exposed to the oral cavity. The multi-variate analysis showed that the presence of an adjacent implant, a longer time of the implant in function, limited MT, reduced KMW and increased BBD were significantly associated with the presence of a PSTD.

CONCLUSIONS

PSTDs are common findings in the esthetic region. Several risk indicators for this condition, such as presence of an adjacent implant, increased time in function of the implant, higher BBD, lower KMW and MT were identified. This article is protected by copyright. All rights reserved.

Variations in vertical mucosal thickness at edentulous ridge according to site and gender measured by cone-beam computed tomography

Background

The vertical thickness of the peri-implant mucosa is associated with the amount of post treatment marginal bone loss. However, the variations in mucosal thickness at the different edentulous sites have been sparsely documented. The purpose of the study was to conduct a survey of the frequency distribution of variations in mucosal thickness at the different sites of the edentulous alveolar ridge and to compare them according to gender.

Our study included 125 partially edentulous patients having a total of 296 implant sites. Cone-beam computed tomography (CBCT) scans were obtained by placing a diagnostic template with a radiopaque crown indicator on the ridge to determine the mucosal thickness at the crest of the alveolar ridge.

Results

The mucosal thickness was 3.0±1.3 mm in the maxilla, which was significantly greater than the mucosal thickness of 2.0±1.0 mm in the mandible (p<0.001). In both the maxilla and the mandible, the mucosa was the thickest in the anterior region, followed by the premolar and molar regions. Sites were further classified into two groups based on whether the mucosal thickness was greater than 2 mm. In the mandible, more than half of the sites showed a mucosal thickness of 2 mm or less.

Conclusions

Although this study was a limited preoperative study, the vertical mucosal thickness at the edentulous ridge differed between the maxillary and mandibular regions. The majority of sites in the mandibular molar region had a mucosal thickness of less than 2 mm. Practitioners might be able to develop an optimal dental implant treatment plan for long-term biologic and esthetic stability by considering these factors.

Validation of an Intra-Oral Scan Method Versus Cone Beam Computed Tomography Superimposition to Assess the Accuracy between Planned and Achieved Dental Implants: A Randomized In Vitro Study

Computer aided implantology is the safest way to perform dental implants. The research of high accuracy represents a daily effort. The validated method to assess the accuracy of placed dental implants is the superimposition of a pre-operative and a post-operative cone beam computed tomography (CBCT) with planned and placed implants. This procedure is accountable for a biologic cost for the patient. To investigate alternative procedure for accuracy assessment, fifteen resin casts were printed. For each model, six implants were digitally planned and then placed following three different approaches: (a) template guided free hand, (b) static computer aided implantology (SCAI), and (c) dynamic computer aided implantology (DCAI). The placement accuracy of each implant was performed via two methods: the CBCT comparison described above and a matching between implant positions recovered from the original surgical plan with those obtained with a post-operative intraoral scan (IOS). Statistically significant mean differences between guided groups (SCAI and DCAI) and the free hand group were found at all considered deviations, while no differences resulted between the SCAI and DCAI approaches. Moreover, no mean statistically significant differences were found between CBCT and IOS assessment, confirming the validity of this new method.

Peri-implant marginal mucosa defects: Classification and clinical management

Peri-implant marginal mucosa defects (PMMDs) are alterations of the peri-implant soft tissue architecture characterized by an apical discrepancy of the mucosal margin respective to its ideal position with or without exposure of transmucosal prosthetic components or the implant fixture surface. PMMDs may not only represent an esthetic concern but also predispose to biofilm accumulation and subsequent initiation and progression of peri-implant inflammatory diseases. A treatment-driven classification for tooth-bound, facial PMMDs in non-molar sites, consisting of three different levels of complexity, is proposed. Clinical recommendations pertaining to the prosthetic and surgical management of each type of PMMD, illustrated with practical examples, are provided with the purpose of facilitating decision-making processes in daily practice.

Impact of mucosal phenotype on marginal bone levels around tissue level implants: A prospective controlled trial

BACKGROUND

The aim of this 1-year prospective clinical trial was to compare clinical parameters and marginal bone levels (MBLs) around tissue level implants with a partially smooth collar between patients with thin (≤2 mm) and thick (>2 mm) vertical mucosal phenotypes.

METHODS

Thirty patients needing a single dental implant were recruited and allocated to thin (n = 14) or thick (n = 16) phenotype groups. Post-restoration, clinical (probing depth, recession, width of keratinized mucosa, bleeding on probing, suppuration, implant mobility, plaque index, and gingival index) and radiographic bone level measurements were recorded at different timepoints for 1 year.

RESULTS

Twenty-six patients (13 per group) completed the 1-year examination. No implants were lost (100% survival rate). There were no significant differences (P >0.05) between thin and thick vertical mucosal phenotypes for any clinical parameter or for the radiographic MBL.

CONCLUSIONS

Tissue level implants at 1 year of function placed in thin vertical mucosa achieved similar clinical parameters and radiographic MBLs as those in thick tissue. The formation of the peri-implant supracrestal tissue height plays a key role in MBL than mucosal thickness in tissue level implant.

Influence of Biologically Oriented Preparation Technique on Peri-Implant Tissues; Prospective Randomized Clinical Trial with Three-Year Follow-Up. Part II: Soft Tissues

Purpose: The objective of this prospective randomized clinical trial (RCT) was to analyze and compare the clinical behavior of three types of prosthesis supported by single implants in the posterior region after three years of functional loading. Materials and methods: Seventy-five implants were divided into three groups according to the type of prosthetic restoration: screw-retained crown (group GS); cemented crown without finishing line (biologically oriented preparation technique) (group GBOPT); and conventional cemented crown with finishing line (group GCC). After three years in function, clinical parameters (presence of keratinized mucosa, probing depths, bleeding on probing, and radiographic bone loss) were compared between the three experimental groups. The possible correlation between soft tissue clinical parameters and bone loss was also analyzed. Results: Statistical analysis found significant differences in clinical parameters between the different types of crown, with the cemented restoration without finishing line (BOPT) presenting fewer complications and better peri-implant health outcomes including: significantly different KMW data (mm), with significant differences between groups GBOPT and GCC (p < 0.001, Kruskal-Wallis test), with GBOPT obtaining larger quantities of keratinized mucosa (KM); statistically significant differences in probing depth (PD) values between groups GBOPT and GCC (p = 0.010, Kruskal-Wallis test); significant differences in bleeding on probing (BOP) between groups GBOPT and GCC (p = 0.018, Chi2 test) in favor of GBOPT. Conclusions: Soft tissue behavior around implants is related to the type of prosthetic restoration used, with cemented prostheses with BOPT presenting better peri-implant soft tissue behavior.