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

3D-Analysis of Peri-Implant Soft Tissue Gain With Collagen Matrix and Connective Tissue Graft: A Randomized Control Trial

OBJECTIVES

To compare the efficacy of the connective tissue graft (SCTG) and the collagen matrix (VXCM) in terms of soft tissue gain at the buccal site around a single implant.

METHODS

The study was designed as a randomized, controlled clinical trial. This trial was registered in ClinicalTrial.gov with the identifier NCT05870774 and is accessible under the following link: https://clinicaltrials.gov/study/NCT05870774?term=NCT05870774&rank=1. This clinical trial was not registered prior to participant recruitment and randomization. Patients with a single tooth gap and horizontal soft tissue thickness deficiency were enrolled in the study. Sites were randomly allocated to the control (SCTG) or test group (VXCM: Geistlich Fibro-Gide, Geistlich Pharma AG, Wolhusen, Switzerland) to augment buccal soft tissue thickness. The primary outcome was soft tissue gain 3 months post-op. Secondary outcomes included soft tissue gain 6 months post-op, the pink aesthetic score (PES), and patient-reported outcome measures (PROMs).

RESULTS

Patients' recruitment started on 28 October 2021 and ended on 25 December 2022. Thirty-two patients were enrolled and subjected to intervention. Sixteen patients were included per group. Three months post-op, soft tissue gain at the buccal site was 1.77 ± 0.61 mm in the VXCM group and 1.26 ± 0.41 mm in the SCTG group (p = 0.0003). Six months post-op, soft tissue gain was 1.11 ± 0.44 mm in the VXCM group and 1.43 ± 0.81 mm in the SCTG group (p = 0.0459). PROMs, including pain perception, favored the VXCM group. SCTG demonstrated favored results in PES.

CONCLUSION

SCTG remains the gold standard for increasing soft tissue thickness in terms of the clinical result.

Gingival phenotype classification by visual and probe visibility assessments: Relationship with thickness and probe design

BACKGROUND

This study investigated the agreement among dentists in classifying gingival phenotype (GP) through periodontal probe visibility (PPV) assessment with various probe types and the visual method. Additionally, the relationship between GP classifications and gingival thickness (GT) was evaluated.

METHODS

Photographs were taken with standard periodontal probe (SPP), color-coded periodontal probe (CCPP) tips in white, green, and blue, as well as metal phenotype probe (MPP) tips in gray and black. Evaluators (periodontist, periodontics resident, endodontics resident, dental student) assessed the photographs and classified the GPs. GT was measured by trans gingival probing.

RESULTS

Visual method showed poor to fair agreement to classify GP. The lowest agreement regarding PPV was noted with white-tipped CCPP. The highest agreement in singular PPV was observed with CCPP blue (κ = 0.932), followed by CCPP green (κ = 0.791), MPP black (κ = 0.783), SPP (κ = 0.730), and MPP gray (κ = 0.690). Combined PPV data revealed fair to moderate agreement with CCPP and moderate to substantial agreement with MPP in GP classification. The corresponding GT to different GP classifications based on combined PPV were comparable. The agreement between SPP and CCPP in classifying non-thin phenotypes was 89.8%, while the agreement between SPP and MPP was 75.4%. Based on PPV, no significant GT cutoff value was found to distinguish between thin and non-thin phenotypes.

CONCLUSION

Determining a precise GT that guarantees the visibility of a given probe can be difficult when evaluating GP. Regardless of the type of probe, the PPV method has a high potential for misclassifying GP, despite having an acceptable agreement.

PLAIN LANGUAGE SUMMARY

Gingival phenotype (GP) is constituted by thickness of the gums and width of keratinized tissue around teeth. Direct visual evaluation or evaluating a periodontal probe's visibility beneath gums are established techniques to classify gingival phenotype. This study investigated how dentists classify GP using visual assessments and different types of periodontal probes, while also exploring the relationship between GP classifications and gingival thickness. Results showed varied agreement among dentists in classifying GP, with lower agreement observed when using certain types of probes, notably the white-tipped phenotype probe. The highest agreement was found with the blue phenotype probe. Data from periodontal probe visibility assessments indicated fair to moderate agreement with certain probes, suggesting some inconsistency in classification methods. Interestingly, GP classification with visual assessments or probes did not correlate with gingival thickness, which may highlight the importance of considering both factors in clinical practice. These findings underline the need for attention when relying solely on visual assessments or specific probe types for accurate GP classification.

Prediction of pink esthetic score using deep learning: A proof of concept

OBJECTIVES

This study aimed to develop a deep learning (DL) model for the predictive esthetic evaluation of single-implant treatments in the esthetic zone.

METHODS

A total of 226 samples, each comprising three intraoral photographs and 12 clinical features, were collected for proof of concept. Labels were determined by a prosthodontic specialist using the pink esthetic score (PES). A DL model was developed to predict PES based on input images and clinical data. The performance was assessed and compared with that of two other models.

RESULTS

The DL model achieved an average mean absolute error (MAE) of 1.3597, average root mean squared error (MSE) of 1.8324, a Pearson correlation of 0.6326, and accuracies of 65.93 % and 85.84 % for differences between predicted and ground truth values no larger than 1 and 2, respectively. An ablation study demonstrated that incorporating all input features yielded the best performance, with the proposed model outperforming comparison models.

CONCLUSIONS

DL demonstrates potential for providing acceptable preoperative PES predictions for single implant-supported prostheses in the esthetic zone. Ongoing efforts to collect additional samples and clinical features aim to further enhance the model's performance.

CLINICAL SIGNIFICANCE

The DL model supports dentists in predicting esthetic outcomes and making informed treatment decisions before implant placement. It offers a valuable reference for inexperienced and general dentists to identify esthetic risk factors, thereby improving implant treatment outcomes.

Evaluation of palatal mucosal thickness in maxillary posterior teeth using cone-beam computed tomography combined with intraoral scanning: a cross-sectional study on correlating factors

OBJECTIVES

Cone-beam computed tomography (CBCT) combined with intraoral scanning (IOS) technology was used to measure and analyze the variation patterns of the palatal masticatory mucosa (PMM) in the maxillary posterior region and its correlation with gender, gingival biotype (GB), and the palatal bone thickness (PBT), thereby establishing a theoretical foundation for autogenous soft tissue augmentation procedures.

MATERIALS AND METHODS

A total of 57 Han Chinese patients and 342 affected teeth were included in the study. CBCT and IOS data were obtained for all participants, and 3D models were constructed by segmenting CBCT images based on standardized parameters, followed by alignment with IOS data using reference points. Measurements were conducted at predetermined intervals to evaluate PMM, PBT, and GB. The variability of PMM from the first premolar to the first molar was analyzed bilaterally by gender, age, and GB using t-tests and Games-Howell post-hoc analysis. Pearson's correlation test examined the relationship between PMM and PBT, while linear regression models were utilized to evaluate associations between PMM and clinical factors such as gender, age, and PBT.

RESULTS

There was no statistically significant difference in PMM between the left and right sides of the maxilla (P > 0.05). Overall, PMM increased with greater distance from the gingival margin, and statistically significant differences were observed between specific measurement points at different tooth positions. The second premolar exhibited the greatest thickness at 6 mm, 8 mm, and 10 mm. Gender had a relatively minor impact on PMM. Significant differences in PMM were observed across age groups, with the middle-aged group showing greater PMM compared to the younger group (P < 0.05). At 2 mm from the first molar's gingival margin, significant PMM differences were identified between different GB (P < 0.05). The correlation between PBT and PMM was weak. Regression analysis revealed age as a primary determinant of PMM, with gender and PBT exerting site-specific effects.

CONCLUSIONS

CBCT combined with IOS proved effective in measuring maxillary PMM. The maxillary posterior region exhibited a symmetrical distribution of PMM, with premolar areas identified as optimal for soft tissue graft harvesting. While no significant correlation was found with gender, GB, or PBT, the mucosa was notably thicker in middle-aged individuals.

CLINICAL RELEVANCE

This study presents comprehensive data on PMM thickness across various tooth positions and distances from the gingival margin, facilitating the identification of optimal donor sites for autologous grafts. It highlights regional and ethnic variations in PMM thickness among Han Chinese patients and validates the combined use of CBCT and IOS for accurate, non-invasive measurements.

Long-Term Clinical and Radiographic Outcomes of Hydrophilic Implants: A 10-Year Study in a Specialist Private Practice

AIM

To report the 10-year clinical and radiographic outcomes of implants placed in grafted (GBR) and non-grafted (no-GBR) sites in a Swiss specialist private practice using hydrophilic implants with a low surface roughness flange.

METHODS

Fifty consecutively enrolled patients received 159 hydrophilic implants with a low surface roughness flange. A first re-evaluation was performed 1 year after delivery of restoration (T1). An additional examination was performed at the 10-year follow-up (T2) including the assessment of clinical (i.e., periodontal/peri-implant pockets probing depths (PPD) (mm), full-mouth bleeding score (%), implant survival rate, mid-buccal keratinized mucosa (KM) width in mm, and peri-implant phenotype), and radiographic (i.e., marginal bone level change [ΔMBL]) outcomes. Biological, mechanical and technical complications were also recorded.

RESULTS

Out of the initial cohort, 22 patients (9/40.9% male and 13/59% female) and 63 implants (47 with GBR, 16 without GBR), could be re-examined at T2. Overall, ΔMBL (T2-T1) was -0.56 ± 0.96 mm. In the GBR group, ΔMBL were significantly higher at the distal sites compared to the no-GBR group (-0.75 ± 1.17 mm vs. -0.12 ± 1.29 mm, p = 0.045), however, in the GBR group MBL started at a higher level at T1 but were similar with the no-GBR group at T2. Implant survival was 100% with only very few technical complications (6.3%). Mean PPD amounted to 3.84 ± 1.00 mm with significantly higher values in the GBR group (3.98 ± 1.08 mm vs. 3.45 ± 0.60 mm; p = 0.016). Nineteen implants (30.1%) were diagnosed with peri-implant health while 44 (69.9%) presented with peri-implant mucositis.

CONCLUSION

Within the limitations of this study, favorable clinical and radiographic conditions were recorded around hydrophilic implants with a low surface roughness flange placed in pristine and augmented bone after 10 years in function.

Management of Soft Tissue Defects Around Single Implants: A Systematic Review of the Literature

OBJECTIVES

The aim of this systematic review was to assess the effectiveness of the available techniques for the management of peri-implant soft tissue defects around single implants in the anterior region.

MATERIAL AND METHODS

A comprehensive search was conducted in PubMed (MEDLINE), Web of Science (all databases), and Cochrane, using keywords and MeSH terms related to the topic. This systematic review included prospective interventional studies with a minimum of 10 patients and at least 6 months of follow-up.

RESULTS

A total of 13 articles were included, with eight focusing on outcomes related to buccal soft tissue dehiscence coverage procedures and the remaining five investigating interventions aimed at augmenting soft tissue thickness. Coronally advanced flap in combination with connective tissue graft was the most effective technique for buccal soft tissue dehiscence coverage in the medium and long term. In terms of increasing soft tissue thickness, both connective tissue graft and acellular dermal matrix demonstrated satisfactory short-term outcomes; however, their long-term efficacy remains unclear.

CONCLUSIONS

Soft tissue augmentation procedures resulted in satisfactory outcomes, in terms of buccal soft tissue dehiscence coverage and soft tissue thickness increase, around single implants in the esthetic area. Peri-implant plastic surgery has improved both the esthetic appearance and quality of life of patients.

PROSPERO REGISTRATION CODE

CRD42023398424.

Volumetric changes of porcine collagen matrix and free gingival grafts for soft-tissue grafting to increase the width of keratinized tissue around dental implants: a retrospective clinical study

AIM

To compare three-dimensional changes of aporcine derived collagen matrix (CM) and free gingival grafts (FGG) for increasing keratinized tissue (KT) at dental implants over a 24-month follow-up period.

MATERIALS AND METHODS

This retrospective study enrolled 25 patients exhibiting 41 implants with deficient KT width (i.e., < 2 mm) who underwent soft tissue augmentation using either CM (11 patients/15 implants) or FGG (14 patients/26 implants). The primary outcome was tissue thickness change (mm) at treated implant sites between 1- (S0), 12- (S1), and 24-months (S2). Secondary outcome was the changes of KT width over a 24-month follow-up period.

RESULTS

Dimensional analyses from S0 to S1 and from S0 to S2 revealed a mean decrease in tissue thickness of -0.05 ± 0.35 mm and - 0.31 ± 0.41 mm in the CM group, and - 0.23 ± 0.38 mm and - 0.22 ± 0.81 mm in the FGG group, with no significant differences found between the groups (S0-S1: p = 0.14, S0-S2: p = 0.58). Within S1 and S2, the CM and FGG groups displayed comparable tissue thickness reduction (CM: -0.32 ± 0.53 mm, FGG: -0.02 ± 0.21 mm; p = 0.07). The FGG group exhibited a significantly greater KT gain 24-months compared to the CM group (CM: 1.50 ± 1.14 mm, FGG: 4.04 ± 1.65 mm; p < 0.001).

CONCLUSIONS

CM and FGG were associated with comparable three-dimensional thickness changes over a period of 24 months. A significantly wider KT band could be established in the FGG group.

Association of Peri-Implant Mucosa Dimensions With Emergence Profile Angles of the Implant Prosthesis

OBJECTIVES

The primary aim of this cross-sectional study was to investigate the association between prosthesis design and peri-implant mucosa dimensions and morphology. The secondary aim was to investigate associations between mucosal dimensions and the presence of mucositis.

MATERIALS AND METHODS

Forty-seven patients with 103 posterior bone level implants underwent clinical and radiographic examination, including cone beam computer tomography and intraoral optical scanning. Three-dimensional models for each implant and peri-implant mucosa were constructed. Vertical mucosa height (TH), horizontal mucosa width at implant platform (TW), and 1.5 mm coronal of the platform (TW1.5), as well as mucosal emergence angle (MEA), deep angle (DA), and total contour angle (TA) were measured at six sites for each implant.

RESULTS

There was a consistent correlation between peri-implant mucosa width and height (β = 0.217, p < 0.001), with the width consistently surpassing height by a factor of 1.4-2.1. All three angles (MEA, DA, TA) were negatively associated with mucosa height (p < 0.001), while DA was negatively associated with mucosa width (TW1.5) (p < 0.001, β = -0.02, 95% CI: -0.03, -0.01). There was a significant negative association between bleeding on probing (BoP) and mucosa width at platform (OR 0.903, 95% CI: 0.818-0.997, p = 0.043) and 1.5 coronal (OR 0.877, 95% CI: 0.778-0.989, p = 0.033). Implants with less than half sites positive for BoP (0-2/6) had significantly higher mucosa height (OR 3.51, 95% CI: 1.72-7.14, p = 0.001).

CONCLUSIONS

Prosthesis design can influence the dimensions of the peri-implant mucosa, with wider emergence profile angles associated with reduced peri-implant mucosa height. In particular, a wider deep angle is associated with reduced mucosa width in posterior sites. Reduced peri-implant mucosa height and width are associated with more signs of inflammation.

TRIAL REGISTRATION

Registered in Thai Clinical Trials Registry: http://www.thaiclinicaltrials.org/show/TCTR20220204002.

Relationship between soft tissue dimensions and tomographic radial root position classification system for immediate implant installation

The aim of this study was to evaluate the relationship between soft tissue dimensions and radial root position (RRP) classification for immediate implant placement on maxillary anterior teeth. Maxillary anterior teeth (n = 420) were analyzed in the radial plane of cone beam computed tomography (CBCT) scans. Each tooth was classified according to its RRP: class I, (IA, IB); class II (IIA, IIB) class III; class IV, and class V. Soft tissue thickness at different landmarks, supracrestal soft tissue height, and crestal bone thickness were measured in CBCT. Keratinized tissue width was clinically measured. Gingival phenotype (thick or thin) was evaluated by transparency of the periodontal probe and at the landmark 2 mm from the gingival margin in CBCT. Class I tooth position accounted for 31.7%, class II for 45%, class III for 13.3%, class IV for 0.5%, and class V for 9.5%. The gingival phenotype was associated with RRP (χ2 test, p < 0.05). Soft tissue dimensions were significantly different over RRP classes (ANOVA and Tukey tests, p < 0.05). Types IA and IIA presented both thick soft and hard tissues. When planning immediate implants in the anterior maxilla, soft tissue dimensions evaluation should be incorporated into RRP classification to increase the accuracy and predictability of treatment outcomes.

The distally anchored connective tissue graft platform for papilla enhancement: A case report

BACKGROUND

As the need for using dental implants to replace single missing teeth grows, so does the demand for greater esthetic results. However, achieving complete interproximal papillae fill in single-tooth implant restorations remains a challenge. The distally anchored connective tissue platform is a novel soft tissue augmentation technique that consists of harvesting an autogenous connective tissue graft from the palate, folding it, and positioning it at the level of the distal occlusal and buccal surfaces with the help of a distal sling suture to the adjacent distal tooth.

METHODS

This case report describes how a maxillary central incisor with compromised hard and soft tissues were replaced using a comprehensive treatment plan.

RESULTS

The clinical outcomes showed stable mucosal margin levels and complete papillae fill. The patient expressed satisfaction with the achieved results.

CONCLUSIONS

The distally anchored connective tissue graft platform performed at the time of implant placement emerges as a viable and effective soft tissue augmentation technique that yields highly esthetic results.

KEY POINTS

Why is this case new information? To the best of our knowledge, this is the first case report in the literature using the distally anchored connective tissue platform. What are the keys to successful management of this case? Adequate diagnosis and decision-making, resulting in a treatment plan focused on reconstructing both soft and hard tissues in a single-tooth implant within the esthetic area, yield favorable clinical, radiological, and patient-reported outcomes. What are the primary limitations to success in this case? The primary limitation of this study is its reliance on a single case report.

Tooth- and implant-related prognostic factors in treatment planning

Following a comprehensive patient examination, including the assessment of periodontal and peri-implant diseases as well as considering the patient's needs, a pretherapeutic prognosis for each tooth and implant is given. Teeth and implants with a secure pretherapeutic prognosis require simple procedures and may be regarded as secure abutments for function and with a doubtful pretherapeutic prognosis usually need a comprehensive therapy. Such teeth and implants must be brought into the category with a secure prognosis by means of additional therapy such as endodontic, restorative, and surgical procedures. Teeth and implants with a hopeless pretherapeutic prognosis should be extracted/explanted during the initial phase of cause-related therapy (i.e., infection control). For example, teeth with vertical root fracture or unrestorable caries and implants with mobility or unrestorable malposition fall into the category of hopeless units. The primary goal of periodontal and peri-implant therapy should be to arrest disease progression. The latest consensus statement highlights that periodontitis can be successfully controlled and treated teeth can be retained for life. Nevertheless, for patients with uncontrolled contributing factors, the endpoints might not always be achievable, and low disease activity may be an acceptable therapeutic goal. Similarly, the management of peri-implantitis frequently requires surgical intervention following nonsurgical therapy due to incomplete treatment outcomes. Different surgical modalities can be effective and lead to significant improvement; however, achieving complete resolution of peri-implantitis is challenging, not always predictable, and can depend on multiple baseline factors. Therefore, this review aims at summarising available evidence on the rationale for incorporating systemic, lifestyle-related, clinical, and radiographic prognostic factors into treatment planning of patients diagnosed with periodontal and peri-implant diseases.

SURVIVAL RATE OF IMPLANT-SUPPORTED, SINGLE-TOOTH RESTORATIONS BASED ON ZIRCONIA OR METAL ABUTMENT IN PATIENTS WITH TOOTH AGENESIS: A 5-YEARS PROSPECTIVE CLINICAL STUDY

OBJECTIVES

The primary aim was to investigate survival rate of zirconia versus metal abutments, and the secondary aim was clinical outcomes of all-ceramic versus metal-ceramic crowns on single-tooth implants.

METHODS

Patients with tooth-agenesis participated to previously published prospective clinical study with 3-year follow-up were recalled after 5 years. Biological variables included survival and success rate of implants, marginal bone level, modified Plaque and Sulcus Bleeding Index and biological complications. Technical variables included restoration survival rate, marginal adaptation and technical complications. The aesthetic outcome of crowns and peri-implant mucosa in addition to patient-reported outcome were recorded. Descriptive analysis, linear mixed model for quantitative data, or generalized linear mixed model for ordinal categorical data were applied; significance was set to 0.05.

RESULTS

Fifty-three patients (mean age: 32.4 years), with 89 implants participated to the 5-years examination. The implants supported 50 zirconia abutments with 50 all-ceramic (AC) crown and 39 metal abutments with 29 metal-ceramic (MC) and 10 AC crowns. The Implant and restoration survival rate was 100% and 96%, respectively. No clinically relevant biological difference between implants supporting metal or zirconia abutments was registered. The technical complications were veneering fracture of AC-crowns (n = 3), crown loosening of MC-crowns (n = 4) and one abutment screw loosening (MC-crown on metal abutment). MC-crowns had significantly better marginal adaptation than AC-crowns (p = .01). AC-crowns had significantly better color and morphology than MC-crowns (p = .01).

CONCLUSIONS

Zirconia-based single-tooth restorations are reliable alternative materials to metal-based restorations with favorable biological and aesthetic outcome, and few technical complications.

Characteristics of healthy peri-implant tissues

This article forms part of the themed issue on dental implants, with the general dentist being the main intended reader and with particular relevance to primary care dental professionals. It aims to describe the various characteristics of the implant in health, address contemporary developments in implant dentistry and offer some novel insights on the prevention of peri-implant diseases. A healthy implant exhibits specific histological, clinical and radiographic characteristics. Understanding such aspects leads to proper diagnosis and measures to maintain tissue integrity and prevent the development and progression of peri-implant diseases. Moreover, internationally and widely accepted definitions and recommendations based on expert consensus have been put forward to guide day-to-day clinical practice. This information should provide general practitioners with the means necessary to achieve the best possible outcome for their patients.

A Randomized Controlled Trial Comparing Collagen Matrix to Hemostatic Gelatin Sponge as Socket Seal in Alveolar Ridge Preservation

(1) Objectives: This study aimed to compare a collagen matrix to a hemostatic gelatin sponge as a socket seal in alveolar ridge preservation (ARP). (2) Methods: Systemically healthy patients planned for ARP at two sites with more than 50% of the buccal bone wall remaining after tooth extraction were eligible for inclusion. ARP involved socket grafting using collagen-enriched deproteinized bovine bone mineral. Sites were then randomly assigned to the test group (collagen matrix) or the control group (hemostatic gelatin sponge). The primary outcome was soft tissue thickness in the center of the site at 4 months, analyzed on cone-beam computed tomography. Secondary outcomes included the buccal and lingual soft tissue heights, horizontal bone loss, buccal soft tissue profile changes, wound dimensions, and Socket Wound Healing Score (SWHS). (3) Results: In total, 18 patients (12 females, 6 males) with a mean age of 57.3 years (SD 11.1) were included. Four months after ARP, the soft tissue thickness in the center of the site amounted to 2.48 mm (SD 0.70) in the test group and 1.81 mm (SD 0.69) in the control group. The difference of 0.67 mm (95% CI: 0.20-1.14) in favor of the collagen matrix was statistically significant (p < 0.009). The buccal soft tissue height was also statistically significantly higher for the collagen matrix (0.72 mm; 95% CI: 0.06-1.38; p = 0.034). A trend favoring the collagen matrix was found for the lingual soft tissue height (p = 0.066). No significant differences between the groups in terms of horizontal bone loss, buccal soft tissue profile changes, wound dimensions, and the SWHS were found. (4) Conclusions: The absence of significant differences in hard tissue outcomes suggests that both the collagen matrix and hemostatic gelatin sponge effectively sealed the extraction socket and supported bone preservation. However, the collagen matrix better maintained soft tissue dimensions. The clinical relevance of this finding with respect to the necessity for adjunctive soft tissue augmentation at the time of implant placement is yet to be studied.

Non-invasive assessment of peri-implant mucosal thickness: A cross-sectional study

BACKGROUND

This study aimed to evaluate the reliability and reproducibility of different non-invasive methods for the assessment of peri-implant mucosal thickness.

METHODS

Subjects with two adjacent dental implants in the central maxillary region were included in this study. Three different methods to assess facial mucosal thickness (FMT) were compared: digital file superimposition using Digital Imaging and Communication in Medicine (DICOM) and stereolithography (STL) files of the arch of interest (DICOM-STL), DICOM files alone, and non-ionizing ultrasound (US). Inter-rater reliability agreements between different assessment methods were analyzed using inter-class correlation coefficients (ICCs).

RESULTS

A total of 50 subjects with 100 bone-level implants constituted the study population. Assessment of FMT using STL and DICOM files demonstrated excellent inter-rater reliability agreement. Mean ICC values of 0.97 and 0.95 were observed in the DICOM-STL and DICOM groups, respectively. Comparison between the DICOM-STL and US revealed good agreement, with an ICC of 0.82 (95% CI: 0.74 to 0.88) and a mean difference of -0.13 ± 0.50 mm (-1.13 to 0.86). Comparison between DICOM files alone versus US showed good agreement, with an ICC of 0.81 (95% CI: 0.73 to 0.89) and a mean difference of -0.23 ± 0.46 mm (-1.12 to 0.67). Comparison between DICOM-STL and DICOM files revealed excellent agreement, with an ICC of 0.94 (95% CI: 0.91 to 0.96) and a mean difference of 0.1 ± 0.29 mm (LOA -0.47 to 0.46).

CONCLUSIONS

Quantification of peri-implant mucosal thickness via analysis of DICOM-STL files, DICOM files, or US assessment are comparably reliable and reproducible methods.

Complications following alveolar ridge augmentation procedures

Oral rehabilitation through implant supported dental restorations often requires a ridge augmentation procedure (RAP) prior to implant fixture placement since tooth extraction/loss results in alveolar ridge deficiencies. Although RAP-related surgical techniques and biomaterials have been in practice for several decades, outcomes are not always predictable. Post-surgical complications experienced during the early or late wound healing phases may jeopardize the targeted ideal ridge dimensions, required for implant fixture placement, and may have other consequences, such as negatively impacting the patient's quality of life. This review describes reported post-surgical complications following RAP under the following subtitles: complications by tissue type, complications in function and aesthetics, complications by healing time, complications by biomaterial type, and complications by surgical protocol modalities. Specifically, RAP performed by using particulate bone graft substitutes and related complications are explored. Modalities developed to prevent/manage these complications are also discussed.

The effect of different abutment materials on peri-implant tissues-A systematic review and meta-analysis

OBJECTIVES

In patients with dental implants, what is the effect of transmucosal components made of materials other than titanium (alloys) compared to titanium (alloys) on the surrounding peri-implant tissues after at least 1 year?

MATERIALS AND METHODS

This systematic review included eligible randomized controlled trials identified through an electronic search (Medline, Embase and Web of Science) comparing alternative abutment materials versus titanium (alloy) abutments with a minimum follow-up of 1 year and including at least 10 patients/group. Primary outcomes were peri-implant marginal bone level (MBL) and probing depth (PD), these were evaluated based on meta-analyses. Abutment survival, biological and technical complications and aesthetic outcomes were the secondary outcomes. The risk of bias was assessed with the RoB2-tool. This review is registered in PROSPERO with the number (CRD42022376487).

RESULTS

From 5129 titles, 580 abstracts were selected, and 111 full-text articles were screened. Finally, 12 articles could be included. Concerning the primary outcomes (MBL and PD), no differences could be seen between titanium abutment and zirconia or alumina abutments, not after 1 year (MBL: zirconia: MD = -0.24, 95% CI: -0.65 to 0.16, alumina: MD = -0.06, 95% CI: -0.29 to 0.17) (PD: zirconia: MD = -0.06, 95% CI: -0.41 to 0.30, alumina: MD = -0.29, 95% CI: -0.96 to 0.38), nor after 5 years. Additionally, no differences were found concerning the biological complications and aesthetic outcomes. The most important technical finding was abutment fracture in the ceramic group and chipping of the veneering material.

CONCLUSIONS

Biologically, titanium and zirconia abutments seem to function equally up to 5 years after placement.

Three-dimensional changes of a porcine collagen matrix and free gingival grafts for soft tissue augmentation to increase the width of keratinized tissue around dental implants: a randomized controlled clinical study

BACKGROUND

Emerging clinical data points to the relevance of the presence of keratinized tissue (KT). Although apically positioned flap/vestibuloplasty along with free gingival graft (FGG) is considered as a standard intervention for augmenting KT, substitute materials appear to be a viable treatment alternative. So far, there is a lack of data investigating the dimensional changes at implant sites treated with soft-tissue substitutes or FGG.

AIM

The present study aimed at comparing three-dimensional changes of a porcine derived collagen matrix (CM) and FGG for increasing KT at dental implants over a 6-month follow-up period.

MATERIALS AND METHODS

The study enrolled 32 patients exhibiting deficient KT width (i.e., < 2 mm) at the vestibular aspect who underwent soft tissue augmentation using either CM (15 patients/23 implants) or FGG (17 patients/31 implants). The primary outcome was defined as tissue thickness change (mm) at treated implant sites between 1- (S0), 3- (S1), and 6-months (S2). Secondary outcomes considered changes of KT width over a 6-month follow-up period, surgical treatment time, and patient-reported outcomes.

RESULTS

Dimensional analyses from S0 to S1 and from S0 to S2 revealed a mean decrease in tissue thickness of - 0.14 ± 0.27 mm and - 0.04 ± 0.40 mm in the CM group, and - 0.08 ± 0.29 mm and - 0.13 ± 0.23 mm in the FGG group, with no significant differences noted between the groups (3 months: p = 0.542, 6 months: p = 0.659). Likewise, a comparable tissue thickness decrease was observed from S1 to S2 in both groups (CM: - 0.03 ± 0.22 mm, FGG: - 0.06 ± 0.14 mm; p = 0.467). The FGG group exhibited a significantly greater KT gain after 1, 3 and 6 months compared to the CM group (1 month: CM: 3.66 ± 1.67 mm, FGG: 5.90 ± 1.58 mm; p = 0.002; 3 months: CM: 2.22 ± 1.44; FGG: 4.91 ± 1.55; p = 0.0457; 6 months: CM: 1.45 ± 1.13 mm, FGG: 4.52 ± 1.40 mm; p < 0.1). Surgery time (CM: 23.33 ± 7.04 min.; FGG: 39.25 ± 10.64 min.; p = 0.001) and postoperative intake of analgesics were significantly lower in the CM group (CM: 1.2 ± 1.08 tablets; FGG: 5.64 ± 6.39 tablets; p = 0.001).

CONCLUSIONS

CM and FGG were associated with comparable three-dimensional thickness changes between 1 and 6 months. While a wider KT band could be established with FGG, the use of CM significantly reduced surgical time and patients´ intake of analgesics.

Transcriptome analysis of human peri-implant soft tissue and periodontal gingiva: a paired design study

OBJECTIVES

Limited information is available about the biological characterization of peri-implant soft tissue at the transcriptional level. The aim of this study was to investigate the effect of dental implant on the soft tissue in vivo by using paired samples and compare the differences between peri-implant soft tissue and periodontal gingiva at the transcriptional level.

METHODS

Paired peri-implant soft tissue and periodontal gingiva tissue from 6 patients were obtained, and the pooled RNAs were analyzed by deep sequencing. Venn diagram was used to further screen out differentially expressed genes in every pair of samples. Annotation and enrichment analysis was performed. Further verification was done by quantitative real-time PCR.

RESULTS

Totally 3549 differentially expressed genes (DEGs) were found between peri-implant and periodontal groups. The Venn diagram further identified 185 DEGs in every pair of samples, of which the enrichment analysis identified significant enrichment for cellular component was associated with external side of plasma membrane, for molecular function was protein binding, for biological process was immune system process, and for KEGG pathway was cytokine-cytokine receptor interaction. Among the DEGs, CST1, SPP1, AQP9, and SFRP2 were verified to be upregulated in peri-implant soft tissue.

CONCLUSIONS

Peri-implant soft tissue showed altered expressions of several genes related to the cell-ECM interaction compared to periodontal gingiva.

CLINICAL RELEVANCE

Compared to periodontal gingiva, altered cell-ECM interactions in peri-implant may contribute to the susceptibility of peri-implant diseases. At the transcriptional level, periodontal gingiva is generally considered the appropriate control for peri-implantitis, except regarding the cell-ECM interactions.

Current landmarks for gingival thickness evaluation in maxillary anterior teeth: a systematic review

OBJECTIVES

To identify and report the current landmarks used for measuring gingival thickness (GT) in healthy maxillary anterior teeth.

MATERIAL AND METHODS

The protocol of this Preferred Reporting Items of Systematic Reviews and Meta-Analyses (PRISMA) 2020-compliant systematic review was registered in PROSPERO. A literature search was conducted to identify articles that met the eligibility criteria published up to 2022. The methods of assessing gingival thickness and the landmarks adopted on the studies were described. Primary outcomes were identified, and the frequency of reporting in the selected articles was calculated. Additionally, risk-of-bias assessments were performed for individual articles.

RESULTS

Fifty-eight articles (34 with low risk of bias and 24 with medium risk of bias) were selected. A total of 3638 individuals had their gingival thickness measured. Thirty-nine different landmarks were adopted in the studies. Fifty-six articles with 22 landmarks were included in the meta-analysis. A higher heterogeneity was found between the studies (GT ranged from 0.48 to 2.59 mm, mean GT 1.074; 95% CI: 1.024-1.104). The 3 most used landmarks were 2 mm from gingival margin (10 studies, mean GT 1.170 mm, 95% CI: 1.085-1.254), bone crest (9 studies, mean GT 1.01 mm; 95% CI: 0.937-1.083), and cemento-enamel junction (7 studies, mean GT 1.172 mm; 95% CI: 1.105, 1.239).

CONCLUSIONS

Within the limits of this study, a large heterogeneity in GT was found, and there was no consensus on the ideal landmark for GT measurement.

CLINICAL RELEVANCE

The landmark 2 mm from gingival margin, located at attached gingiva, can be used for GT measurement by clinical and image-based devices. This is an important step for a quantitative instead of a qualitative evaluation of phenotypes.

Soft tissue augmentation with a volume-stable collagen matrix or an autogenous connective tissue graft at implant sites: Five-year results of a randomized controlled trial post implant loading

BACKGROUND

Interventions to augment the mucosal thickness around dental implants are indicated to optimize esthetics and maintain peri-implant health. However, there is a lack of clinical data on the long-term performance of soft tissue substitutes, such as volume-stable collagen matrix (VCMX), compared to autogenous grafts, such as subepithelial connective tissue grafts (SCTGs). This randomized controlled trial aimed to assess 5-year data on clinical and radiographic outcomes at implant sites previously augmented with VCMX or SCTG.

METHODS

Twenty patients were randomly assigned for soft tissue augmentation with VCMX or SCTG at single implant sites. Following abutment connection, final restorations were inserted (baseline; BL) and patients were reexamined up to 5 years (FU-5). Measurements included clinical data, marginal bone levels, mucosal thickness, and ridge contour changes. Nonparametric tests and estimates were applied for the statistical analysis.

RESULTS

The median buccal mucosal thickness increased by 0.3 mm (Q1: -0.8; Q3: 1.0) in the VCMX group (P = 0.656) and 0.3 mm (Q1: 0.0; Q3: 1.0) in the SCTG group (P = 0.188) between BL and FU-5 (intergroup P = 0.752), while the ridge contour decreased by a median of -0.3 mm (-0.9; -0.1) (P = 0.078) for VCMX and -0.3 mm (-0.4; -0.2) (P = 0.039) for SCTG (intergroup P = 0.817). Peri-implant health was maintained in both groups with stable clinical and radiographic outcomes and without significant differences between the treatments.

CONCLUSION

Despite the limited power and considerable dropout rate in the present study, soft tissue augmentation at implant sites with either VCMX or SCTG resulted in similar stable peri-implant tissues, favorable esthetics, and clinically negligible contour changes at 5 years post loading.

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.

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.