Importance of keratinized mucosa around dental implants: Consensus report of group 1 of the DGI/SEPA/Osteology Workshop

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.

The effect of one-time abutment placement on clinical and radiographic outcomes: A 5-year randomized clinical trial

OBJECTIVE

The aim of this study was to evaluate the long-term (5 years) clinical efficacy of the one-abutment one-time protocol (test) versus the standard of care by placing the definitive abutment on the day of the prosthetic delivery (control).

MATERIALS AND METHODS

In this study, 39 subjects with 60 implants were randomly allocated to either the test or the control group. Changes in the radiographic interproximal bone levels (DIB), modified sulcus bleeding index, probing depth, modified plaque index, papilla fill (Jemt score), incidence of peri-implantitis and peri-implant mucositis as well as patient-reported outcomes measures (PROMs) were collected and compared at 1, 3 and 5 years.

RESULTS

At 5 years, the control group showed a greater, although not statistically significant, change in mean DIB values (0.97 mm vs. 0.53 mm). Regarding the other clinical parameters evaluated, no statistically significant differences were observed between groups at any time point. At 5 years, 51% of the implants presented peri-implant mucositis (25.5% in the control and 23.5% in the test), and only one implant in the test group developed peri-implantitis.

CONCLUSIONS

The connection and disconnection of healing abutments during the healing period was not associated with higher long-term bone loss. Clinical outcomes and PROMs were similar between groups.

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.

Maintenance of peri-implant health in general dental practice

The long-term maintenance or restoration of peri-implant tissues' health depends on the strategic implementation of preventive measures and interventions. These measures should be initiated before implant placement and continued throughout a patient's lifetime, as part of a tailored and comprehensive supportive peri-implant care (SPIC) programme. Central to the clinical efforts of maintaining and rehabilitating peri-implant tissues are several key factors, including the ongoing assessment and frequent monitoring of tissue health and stability, proactive oral health promotion, the control of risk factors and indicators and the provision of professional plaque biofilm removal. It is of paramount importance to underline that SPIC should not limit its scope exclusively to patients already in a state of peri-implant health; in fact, it is imperative that it should extend its protective effect to individuals who have been previously diagnosed and treated for peri-implant diseases, focusing on preventing its recurrence and progression, thereby avoiding further complications, such as implant loss.This narrative review presents an overview of the current literature on the maintenance of peri-implant tissues' health and the steps of SPIC providing insights into the critical factors to be considered when managing dental implant patients in the general dental practice.

BSP Implementation of Prevention and Treatment of Peri-implant Diseases - The EFP S3 Level Clinical Practice Guideline

OBJECTIVES

to adapt the supranational European Federation of Periodontology (EFP) Prevention and Treatment of Peri-implant Diseases - The EFP S3 Level Clinical Practice Guideline for UK healthcare environment, taking into account a broad range of views from stakeholders and patients.

SOURCES

This UK version, based on the supranational EFP guideline [1] published in the Journal of Clinical Periodontology, was developed using S3-level methodology, combining assessment of formal evidence from 13 systematic reviews with a moderated consensus process of a representative group of stakeholders, and accounts for health equality, environmental factors and clinical effectiveness. It encompasses 55 clinical recommendations for the Prevention and Treatment of Peri-implant Diseases, based on the classification for periodontal and peri-implant diseases and conditions [2].

METHODOLOGY

The UK version was developed from the source guideline using a formal process called the GRADE ADOLOPMENT framework. This framework allows for adoption (unmodified acceptance), adaptation (acceptance with modifications) and the de novo development of clinical recommendations. Using this framework, following the S3-process, the underlying evidence was updated and a representative guideline group of 111 delegates from 26 stakeholder organisations was assembled into four working groups. Following the formal S3-process, all clinical recommendations were formally assessed for their applicability to the UK and adoloped accordingly.

RESULTS AND CONCLUSION

Using the ADOLOPMENT protocol, a UK version of the EFP S3-level clinical practice guideline for the Prevention and Treatment of Peri-implant Diseases was developed. This guideline delivers evidence- and consensus-based clinical recommendations of direct relevance to the UK healthcare community including the public.

CLINICAL SIGNIFICANCE

The S3-level-guidelines combine evaluation of formal evidence, grading of recommendations and synthesis with clinical expertise of a broad range of stakeholders. The international S3-level-guideline was implemented for direct clinical applicability in the UK healthcare system, facilitating a consistent, interdisciplinary, evidence-based approach with public involvement for the prevention and treatment of peri-implant diseases.

Management of an Implant-Supported Fixed Partial Denture in the Esthetic Zone in a Patient With a Very Limited Mouth Opening: A Case Report

In the maxillary anterior area, the esthetic integration of prosthetic restorations is a challenge, particularly for screw-retained implant prostheses. This case report presents the management and clinical outcome of an old partial edentulous maxillary jaw in an esthetic zone in a young patient with a very limited mouth opening. This patient was rehabilitated with an implant screw-retained fixed partial denture (FPD) using both digital and conventional techniques.

Impact of keratinized mucosa on implant-health related parameters: A 10-year prospective re-analysis study

AIM

To investigate whether the lack of keratinized mucosa (KM) affects peri-implant health after 10 years of loading.

MATERIALS AND METHODS

Data from 74 patients with 148 implants from two randomized controlled studies comparing different implant systems were included and analyzed. Clinical parameters including bleeding on probing (BOP), probing depth (PD), plaque index, marginal bone loss (MBL), and KM width (KMW) at buccal sites were collected at baseline (time of the final prosthesis insertion), 5-year and 10 years postloading. Multivariable logistic and linear regression models by means of a generalized estimated equation (GEE) were used to evaluate the influence of buccal KM on peri-implant clinical parameters; BOP, MBL, PD, and adjusted for implant type (one-piece or two-piece) and compliance.

RESULTS

A total of 35 (24.8%) implants were healthy, 67 (47.5%) had mucositis and 39 (27.6%) were affected by peri-implantitis. In absence of buccal KM (KM = 0 mm), 75% of the implants exhibited mucositis, while in the presence of KM (KMW >0 mm) 41.2% exhibited mucositis. Regarding peri-implantitis, the corresponding percentages were 20% (KM = 0 mm) and 26.7% (KM >0 mm). Unadjusted logistic regression showed that the presence of buccal KM tended to reduce the odds of showing BOP at buccal sites (OR: 0.28 [95% CI, 0.07 to 1.09], p = 0.06). The adjusted logistic regression model revealed that having buccal KM (OR: 0.21 [95% CI, 0.05 to 0.85], p = 0.02) and using two-piece implants (OR: 0.34 [95% CI, 0.15 to 0.75], p = 0.008) significantly reduced the odds of showing BOP. Adjusted linear regression by means of GEE showed that KM and two-piece implants were associated with reduced MBL and MBL changes (p < 0.05).

CONCLUSION

The lack of buccal KM appears to be linked with peri-implant parameters such as BOP and MBL, but the association is weak. The design of one-piece implants may account for their increased odds of exhibiting BOP.

Novel Technique to Reconstruct Peri-Implant Keratinised Mucosa Width Using Xenogeneic Dermal Matrix. Clinical Case Series

Reconstruction of sufficient buccal peri-implant keratinised mucosa width (PIKM-W) is reported to reduce the symptoms of peri-implantitis. In order to reduce the drawbacks of autogenous graft harvesting, we investigated a novel porcine dermal matrix (XDM, mucoderm®) using a modified surgical technique for augmentation of PIKM-W. Twenty-four patients were recruited with insufficient (<2 mm) PIKM-W. After split thickness flap preparation, the XDM was trimmed, rehydrated and tightly attached to the recipient periosteal bed using modified internal/external horizontal periosteal mattress sutures via secondary wound healing. Change of the PIKM-W and dimension of the graft remodelling were evaluated at 6 and 12 months postoperatively. The mean PIKM-W changed from 0.42 ± 0.47 to 3.17 ± 1.21 mm at 6 M and to 2.36 ± 1.34 mm at 12 M in the maxilla and from 0.29 ± 0.45 mm to 1.58 ± 1.44 mm at 6 M and to 1.08 ± 1.07 mm at 12 M in the mandible. Graft dimensions decreased by 67.7 ± 11.8% and 81.6 ± 16.6% at 6 M, and continued to 75.9 ± 13.9% and 87.4 ± 12.3% at 12 M, in the maxilla and mandible, respectively. Clinical parameters showed statistically significant intra- and intergroup differences between the baseline and 6 and 12 months (p < 0.05). The present technique using the XDM was safe and successfully reconstructed PIKM-W in both arches. The XDM alone seems to be a suitable alternative to autograft for PIKM-W augmentation in the maxilla.

One-Stage Approach to Rehabilitate a Hopeless Tooth in the Maxilla by Means of Immediate Dentoalveolar Restoration: Surgical and Prosthetic Considerations

Contemporary dentistry has increased the demand for predictable functional and esthetic results in a short period of time without compromising the long-term success of rehabilitation. Recent advances in surgical techniques have provided alternatives that allow the prosthetic rehabilitation of complex implant-supported cases through minimally invasive techniques. In this context, immediate dentoalveolar restoration (IDR) was described aiming at restoring function and esthetics through the reconstruction of lost periodontal tissues followed by immediate implant placement in order to minimize treatment time and surgical morbidity in a one-stage approach. Therefore, the aim of this clinical case is to describe the reconstruction and rehabilitation of a hopeless tooth in the maxillary region in a one-stage approach by means of IDR. The proposed steps to rehabilitate the case involved atraumatic dental extraction, immediate implant placement, and hard tissue augmentation by means of cortical-medullary bone graft harvested from the maxillary tuberosity. Afterwards, a provisional restoration was manufactured and installed to the implant allowing immediate prosthesis provisionalization and function in the same operatory time. Six months after the surgical procedure, the final prosthesis was manufactured and installed. The follow-up of nine years demonstrated the preservation of hard and soft tissue without tissue alteration and a successful esthetic outcome. The surgical protocol used allowed the ideal three-dimensional placement of the implant with the restoration of the bone buccal wall, favoring the esthetic and functional outcome of the case with harmony between white and pink esthetics. In conclusion, the employed treatment validated immediate implant-supported restoration of the missing tooth with high predictability. Furthermore, this protocol resulted in fewer surgical interventions, regeneration, and preservation of peri-implant tissues reaching the patient's expectations.

Evaluation of Post-Operative Morbidity and Palatal Wound Healing after Implant Uncovering Surgical Procedure Performed with Apically Positioned Flap (APF) and Leukocyte and Platelet-Rich-Fibrin (L-PRF): An Original Technique

Background and Objectives: Dental implants are recognized as an effective treatment in the management of edentulous patients; controversies surround the connection between the sufficiency of keratinized gingiva (KG) and peri-implant health. Maintaining an ample amount of peri-implant KG is crucial for minimizing gingival inflammation, highlighting the need for regular consideration of soft-tissue augmentation. Among the diverse periodontal plastic surgical procedures, the apically positioned flap (APF) is notable for its ability to enhance the width of keratinized tissue while minimizing patient morbidity. The aim of this study was to evaluate the effects of L-PRF on palatal wound healing and patient discomfort after surgery. Materials and Methods: Twenty patients with two adjacent submerged fixtures in the maxilla and buccal keratinized gingiva widths < 2 mm were treated with APF and L-PRF. Clinical evaluations were performed at 1, 2, 3, and 4 weeks post-surgery, focusing on parameters such as complete wound epithelialization (CWE), postoperative discomfort (D), changes in feeding habits (CFH), alteration of sensitivity (AS) around the wound area, and the consumption of analgesics. Results: Our data revealed CWE in 5 patients by the end of the second week, with the remaining 15 achieving CWE by the end of the third week. For D and CHF, a statistically significant improvement was recorded for all cases between the first and second weeks, as well as AS, although less substantial, by the third week. No significant changes were noted for AS over the initial two weeks. Conclusions: These findings suggest that L-PRF may enhance wound healing and decrease patient discomfort following APF for fixture uncovering.

Influence of the level of compliance with preventive maintenance therapy upon the prevalence of peri-implant diseases

BACKGROUND

A study was made to evaluate peri-implant conditions in compliers and erratic compliers with peri-implant maintenance therapy (PIMT), and to assess the role of site-specific confounders.

METHODS

Erratic PIMT compliers (EC) were defined as presenting attendance < 2×/year, while regular compliers (RC) attended ≥ 2×/year. Generalized estimating equations (GEE) were employed to perform a multivariable multilevel analysis in which the peri-implant condition was established as dependent variable.

RESULTS

Overall, 86 non-smoker patients (42 RC and 44 EC) attending the Department of Periodontology of the Universitat Internacional de Catalunya were recruited consecutively on a cross-sectional basis. The mean period of loading was 9.5 year. An implant placed in an erratic patient has 88% higher probability of presenting peri-implant diseases versus RC. Furthermore, the probability of diagnosis of peri-implantitis was significantly higher in EC versus RC (odds ratio [OR] 5.26; p = 0.009). Among other factors, history of periodontitis, non-hygienic prosthesis, period of implant loading, and modified plaque index (mPI) at implant level were shown to significantly increase the risk of peri-implantitis diagnosis. Although not associated with peri-implantitis diagnosis risk, keratinized mucosa (KM) width, and vestibular depth (VD) were significantly associated to plaque accumulation (mPI).

CONCLUSIONS

Compliance with PIMT was found to be significantly associated with peri-implant condition. In this sense, attending PIMT < 2×/year may be ineffective to prevent peri-implantitis.

Evaluation of the adjunctive use of Er:YAG laser or erythritol powder air-polishing in the treatment of peri-implant mucositis: A randomized clinical trial

AIM

To assess the efficacy of Er:YAG laser (ERL) and erythritol powder air-polishing (AP) in addition to the submarginal instrumentation in the non-surgical treatment of peri-implant mucositis (PM).

MATERIALS AND METHODS

Patients with at least one implant diagnosed with PM were included in the present 6-month randomized clinical trial (RCT). Implants were randomly assigned to one of the three treatment groups after submarginal instrumentation: AP (test 1 group), ERL (test 2 group) or no adjunctive methods (control group). The primary and secondary outcomes were, respectively, bleeding on probing (BoP) reduction and, complete disease resolution (total absence of BoP) and probing pocket depth (PPD) changes. The patient and the implant were considered the statistical unit. A multivariate logistic regression analysis was performed.

RESULTS

A total of 75 patients were enrolled in the study. At each time point, significant BoP and PPD reductions were observed within each group. Intergroup analysis did not show statistically significant differences. Complete disease resolution ranged between 29% and 31%. The logistic regression showed that supramucosal restoration margin, PPD < 4 mm and vestibular keratinized mucosa (KM) significantly influenced the probability to obtain treatment success.

CONCLUSION

The adjunctive use of AP and ERL in PM non-surgical therapy does not seem to provide any significant or clinically relevant benefit in terms of BoP and PPD reductions and complete disease resolution, over the use of submarginal instrumentation alone. Baseline PPD < 4 mm, presence of buccal KM and supramucosal restoration margin may play a role in the complete resolution of PM.

The Influence of History of Severe Periodontitis on Estimated Long-Term Marginal Bone Loss around Implants Restored with Fixed Segmented Full-Arch Rehabilitation

The aim of this study was to analyze the long-term marginal bone level (MBL) of implants supporting fixed full-arch restoration in patients who had previously lost their dentition due to severe periodontitis. This retrospective study included 35 patients in whom 342 implants with internal tapered conical connections were placed. MBL was analyzed radiographically over time and a long-term estimation of MBL was calculated. A mixed linear model with abutment height, graft, diameter and location (maxilla/mandible) as factors and gender, age, implant length and prosthetic variables as covariates was used to evaluate the influence on MBL. MBL in these patients showed an estimator of predictions at 4108 days after loading of -0.307 mm, SE = 0.042. Only 0.15% of implants were radiographically affected with MBL of 3 mm or more. The mixed linear model results showed a main effect of the type of opposing dentition, gender, implant diameter, and abutment height. Particularly, an abutment height of 1 mm had associated larger MBL than the remaining heights. Thus, it can be concluded that dental implants restored with fixed segmented full-arch rehabilitation in patients with a history of severe periodontal disease do not suffer important marginal bone loss if some specific factors are considered, mainly the use of long transmucosal abutments (≥2 mm).

Do soft tissue augmentation techniques provide stable and favorable peri-implant conditions in the medium and long term? A systematic review

OBJECTIVES

To review the available literature on the medium- and long-term effects of soft tissue augmentation (STA) at implant sites and to explore the effects of the different approaches on clinical-, patient-reported, and health-related parameters.

MATERIALS AND METHODS

A comprehensive electronic and manual search was performed to identify prospective clinical studies that assessed the medium- and long-term (≥36 months) outcomes following STA, including number of sites maintaining peri-implant health and number of sites developing peri-implant disease, incidence of complications, stability of the clinical, volumetric, and radiographic parameters, and patient-reported outcome measures (PROMs).

RESULTS

Fifteen studies were included in the qualitative analysis. STA was performed with either a bilaminar- or an apically positioned flap (APF) approach, in combination with autogenous grafts (free gingival graft [FGG] and connective tissue graft [CTG]) or substitutes (acellular dermal matrix [ADM] and xenogeneic cross-linked collagen matrix [CCM]). An overall high survival rate was observed. Most of the augmented implant sites maintained peri-implant health in the medium and long term, with the incidence of peri-implant mucositis and peri-implantitis ranging from 0% to 50% and from 0% to 7.14%, respectively. The position of the soft tissue margin following APF + FGG and bilaminar approaches involving CTG or CCM was found to be stable over time. No substantial changes were reported for plaque score/index, bleeding on probing/bleeding index, and probing depth between early time points and following visits. CTG-based STA procedures resulted in a stable or increased dimension of keratinized mucosa width (KMW) and mucosal thickness (MT)/volumetric outcomes over time, when compared with early follow-ups. Most of the included studies described stable marginal bone levels at the grafted implant sites over time. No substantial changes for patient-reported outcomes and professionally assessed esthetic results were reported at different time points.

CONCLUSIONS

Implants that received STA showed overall high survival rate and relatively low incidence of peri-implantitis in the medium and long term. Augmented sites seem to maintain the level of soft tissue margin and marginal bone over time, while non-augmented implants may exhibit apical shift of the soft tissue margin. The overall favorable early outcomes obtained with STA are maintained in the medium and long term, with an increase in KMW and MT that may be expected over time at CTG-augmented sites.

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.

Primordial and primary prevention of peri-implant diseases: A systematic review and meta-analysis

AIM

This systematic review and meta-analysis aims to assess the efficacy of risk factor control to prevent the occurrence of peri-implant diseases (PIDs) in adult patients awaiting dental implant rehabilitation (primordial prevention) or in patients with dental implants surrounded by healthy peri-implant tissues (primary prevention).

MATERIALS AND METHODS

A literature search was performed without any time limit on different databases up to August 2022. Interventional and observational studies with at least 6 months of follow-up were considered. The occurrence of peri-implant mucositis and/or peri-implantitis was the primary outcome. Pooled data analyses were performed using random effect models according to the type of risk factor and outcome.

RESULTS

Overall, 48 studies were selected. None assessed the efficacy of primordial preventive interventions for PIDs. Indirect evidence on the primary prevention of PID indicated that diabetic patients with dental implants and good glycaemic control have a significantly lower risk of peri-implantitis (odds ratio [OR] = 0.16; 95% confidence interval [CI]: 0.03-0.96; I² : 0%), and lower marginal bone level (MBL) changes (OR = -0.36 mm; 95% CI: -0.65 to -0.07; I² : 95%) compared to diabetic patients with poor glycaemic control. Patients attending supportive periodontal/peri-implant care (SPC) regularly have a lower risk of overall PIDs (OR = 0.42; 95% CI: 0.24-0.75; I² : 57%) and peri-implantitis compared to irregular attendees. The risk of dental implant failure (OR = 3.76; 95% CI: 1.50-9.45; I² : 0%) appears to be greater under irregular or no SPC than regular SPC. Implants sites with augmented peri-implant keratinized mucosa (PIKM) show lower peri-implant inflammation (SMD = -1.18; 95% CI: -1.85 to -0.51; I² : 69%) and lower MBL changes (MD = -0.25; 95% CI: -0.45 to -0.05; I² : 62%) compared to dental implants with PIKM deficiency. Studies on smoking cessation and oral hygiene behaviors were inconclusive.

CONCLUSIONS

Within the limitations of available evidence, the present findings indicate that in patients with diabetes, glycaemic control should be promoted to avoid peri-implantitis development. The primary prevention of peri-implantitis should involve regular SPC. PIKM augmentation procedures, where a PIKM deficiency exists, may favour the control of peri-implant inflammation and the stability of MBL. Further studies are needed to assess the impact of smoking cessation and oral hygiene behaviours, as well as the implementation of standardized primordial and primary prevention protocols for PIDs.

Marginal bone changes around platform-switched conical connection implants placed 1 or 2 mm subcrestally: A multicenter crossover randomized controlled trial

INTRODUCTION

This study analyzes early marginal bone modifications occurring around platform-switched implants with conical connection placed 1 or 2 mm subcrestally.

METHODS

This crossover randomized controlled trial enrolled partially edentulous patients needing two implants in either the posterior maxilla or mandible. Each patient received two platform-switched implants with conical connection inserted 2 mm (Test) and 1 mm (Control) subcrestally. Definitive abutments were immediately connected and, after 4 months of unsubmerged healing, screwed metal-ceramic crowns were delivered. Radiographs were taken at implant placement (T0), prosthesis delivery (T1), and after 1 year of prosthetic loading (T2).

RESULTS

Fifty-one patients (25 males and 26 females; mean age 61.2 ± 12.1 years) totaling 102 implants were included in the final analysis. Mean peri-implant bone level (PBL) reduction from T0 to T2 was not significantly different around Test (0.49 ± 0.32 mm) and Control implants (0.46 ± 0.35 mm; p = 0.66). Multivariate linear regression models highlighted a significant positive correlation between history of periodontitis and PBL reduction. At T2, no Test group implant and 6 Control group implants exhibited PBL below the implant platform (11.8% of Control group implants).

CONCLUSION

No significant differences in peri-implant marginal bone changes were demonstrated after 1 year of prosthetic loading between platform-switched implants with conical connection inserted either 1 or 2 mm subcrestally. However, 2 mm subcrestal placement resulted in deeper implant positioning at T2, with no exposure of treated implant surface and potential preventive effect against subsequent peri-implant pathology.

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.

Impact of local predisposing/precipitating factors and systemic drivers on peri‐implant diseases

BACKGROUND

Strong evidence suggests the infectious nature of peri-implant diseases occurring in susceptible hosts. Epidemiological reports, though, indicate that peri-implantitis is a site-specific entity. Hence, the significance of local factors that may predispose/precipitate plaque accumulation and the impact of systemic drivers that alter the immune response are relevant in the prevention and management of peri-implant disorders.

PURPOSE

The purpose of the present review is to shed light on the significance of local and systemic factors on peri-implant diseases, making special emphasis on the associations with peri-implantitis.

METHODS

The biologic plausibility and supporting evidence aiming at providing a concluding remark were explored in the recent scientific literature for local predisposing/precipitating factors and systemic drivers related to peri-implant diseases.

RESULTS

Local predisposing factors such as soft tissue characteristics, implant position and prosthetic design proved being strongly associated with the occurrence of peri-implant diseases. Hard tissue characteristics, however, failed to demonstrate having a direct association with peri-implant diseases. Robust data points toward the strong link between residual sub-mucosal cement and peri-implant diseases, while limited data suggests the impact of residual sub-mucosal floss and peri-implantitis. Systemic drivers/habits such as hyperglycemia and smoking showed a strong negative impact on peri-implantitis. However, there is insufficient evidence to claim for any link between metabolic syndrome, atherosclerotic cardiovascular disease, and obesity and peri-implant diseases.

CONCLUSION

Local predisposing/precipitating factors and systemic drivers may increase the risk of peri-implant diseases. Therefore, comprehensive anamnesis of the patients, educational/motivational programs and exhaustive prosthetically-driven treatment planning must be fostered aiming at reducing the rate of biological complications in implant dentistry.

Immediate versus delayed implant placement in the esthetic zone: a prospective 3D volumetric assessment of peri-implant tissue stability

PURPOSE

To evaluate the volumetric stability of peri-implant soft and hard tissue prospectively, this study compared immediate versus delayed implants placed in the anterior esthetic region.

METHODS

This non-randomized controlled clinical study included 25 patients, who received an immediate (type 1) or a delayed (type 4) implant placement for the replacement of a single anterior tooth. The anterior maxillae were intraorally scanned at three timepoints: before surgery (S0), 6 months (S1), and 12 months (S2) after surgery. A specific region of interest (ROI), divided into marginal and apical regions, was determined and superimposed for volumetric changes analysis. At 6 and 12 months, the probing depth (PD), bleeding/suppuration on probing (BOP/SUP), modified plaque index (PI), keratinized mucosa (KM) width, mucosal recession (MR), and implant stability (PTV) by means of periotest were recorded.

RESULTS

Between S0-S2, tissue surrounding immediate implants was reduced in 0.37 ± 0.31 mm, whereas delayed implants gained 0.84 ± 0.57 mm mean tissue volume. Peri-implant tissue loss at type 1 implants occurred primarily in the marginal section of the ROI (0.42 ± 0.31 mm), whereas tissue gain at type 4 implants occurred mainly in the apical section (0.83 ± 0.51 mm). These values were significantly different between both groups for the entire ROI (p = 0.0452) and the marginal region (p = 0.0274). In addition, the mean buccal KM width around type 1 implants was significantly wider in comparison with the type 4 implants group after 12 months (p = 0.046). There were no significant differences between groups regarding PD, BOP/SUP, or PTV.

CONCLUSIONS

The results suggest that type 1 implants placed in the esthetic region experience more tissue loss than type 4 implants, thus marginal tissue remodeling should be considered for planning immediate implants placement in the anterior maxillae.

Significance of barrier membrane on the reconstructive therapy of peri-implantitis: A randomized controlled trial

BACKGROUND

The objective of this trial was to investigate the clinical and radiographic significance of using a mixture of mineralized and demineralized allografts in combination (M) or not (NM) with a resorbable cross-linked barrier membrane in the reconstructive therapy of peri-implantitis defects.

METHODS

A two-arm randomized clinical trial was performed in patients diagnosed with peri-implantitis that exhibited contained defects. Clinical parameters were recorded at baseline (T₀ ), 6 months (T₁ ), and 12 months (T₂ ). Radiographic parameters were recorded at T₀ and T₂ . A composite criterion for disease resolution was defined a priori. A generalized linear model of repeated measures with generalized estimation equation statistical methods was used.

RESULTS

Overall, 33 patients (n_implants  = 48) completed the study. At T₂ , mean disease resolution was 77.1%. The use of a barrier membrane did not enhance the probability of disease resolution at T₂ (odds ratio [OR] = 1.55, p = 0.737). Conversely, the odds of disease resolution were statistically associated with the modified plaque index recorded at T₀ (OR = 0.13, p = 0.006) and keratinized mucosa width (OR = 2.10, p = 0.035). Moreover, women exhibited greater odds to show disease resolution (OR = 5.56, p = 0.02).

CONCLUSION

Reconstructive therapy by means of a mixture of mineralized and demineralized allografts is effective in clinically resolving peri-implantitis and in gaining radiographic marginal bone level. The addition of a barrier membrane to reconstructive therapy of peri-implantitis does not seem to enhance the outcomes of contained bone defects (NCT05282667).