WITHDRAWN: Consensus Report of Working Group 2: Soft Tissue Management

Hard and soft tissue alterations using dual-zone concept versus connective tissue graft at maxillary immediate implant placement: A 1-year randomized clinical and volumetric trial

OBJECTIVES

To evaluate the esthetic outcome, as well as clinical, radiographic, and volumetric tissue alterations 1 year after immediate implant placement (IIP) with connective tissue grafting (CTG) versus dual-zone concept (DZ) at sites with thin labial bone in the esthetic zone.

MATERIALS AND METHODS

This randomized clinical trial included 30 patients treated with IIP simultaneous with either CTG or DZ (n = 15 each). Pink esthetic score (PES) was assessed 6 months after crown placement as the primary outcome. Amount of bone labial to the implant, labio-palatal ridge reduction, and crestal bone changes were measured via CBCT after 1 year. Volumetric analysis of linear labial soft tissue contour, interdental, and mid-facial soft tissue level changes, and total volume loss (mm3) were measured after 1 year.

RESULTS

Similar PES was observed in the CTG (12.53 ± 1.13) and DZ (12.13 ± 1.55) groups, with no significant difference (p = 0.42). Likewise, there were no statistically significant differences found between the two groups in labio-palatal bone reduction (mm&%), interdental papillae, and mid-facial gingival levels (p > 0.05). However, the mean vertical crestal bone changes in the CTG and DZ groups were -1.1 ± 0.6 mm and 0.2 ± 1.0 mm, respectively, with a statistically significant difference (p = 0.0002). Moreover, CTG revealed less linear and total volume (mm3) loss in the labial soft tissue which was statistically significant compared to DZ (p = 0.007).

CONCLUSION

Both groups demonstrated the same PES, nevertheless, volumetric analysis revealed twice total labial volume loss in DZ compared to CTG. It might be concluded that the use of CTG with IIP caused less horizontal reduction in the supra-implant complex compared to the DZ.

Profilometric, esthetic, and patient-reported outcomes of the L-shape technique combined with delayed connective tissue grafting in the maxillary anterior region: A 3-year case series study

OBJECTIVE

To evaluate the profilometric, esthetic, and patient-reported outcomes of peri-implant tissues in the maxillary anterior esthetic zone following guided bone regeneration (GBR) using the L-shape technique combined with delayed connective tissue grafting (CTG).

MATERIALS AND METHODS

Profilometric and pink esthetic score (PES) measurements were performed at the time of implant surgery with GBR (T0) and at the 1- (T1), 2- (T2), and 3-year (T3) follow-up. Patient-reported outcomes were also assessed using the Oral Health Impact Profile-14 (OHIP-14) questionnaire. Statistical analysis over 3 years of follow-up assessed changes at time points (T0, T1, T2, and T3) and time periods (T0-T1, T0-T2, and T0-T3) using the Wilcoxon signed-rank test.

RESULTS

A total of 12 patients (57.5 ± 12.3 years) were included in this study. The mean profilometric change in peri-implant tissues over the 3-year follow-up period was 3.49 ± 1.11 mm, and the buccal contours were not significantly different between the comparison periods. The PES remained stable, while all OHIP-14 domain scores improved significantly.

CONCLUSION

Simultaneous implant placement and GBR using the L-shape technique combined with delayed CTG in the maxillary anterior region provides stable buccal profiles and consistent esthetics and improves patient-reported quality of life over a 3-year period.

CLINICAL SIGNIFICANCE

This study demonstrated that GBR using the L-shape technique combined with delayed CTG in the maxillary anterior region improved the buccal profile, esthetics, and patient-reported quality of life.

The use of digital technologies in peri-implant soft tissue augmentation - A narrative review on planning, measurements, monitoring and aesthetics

OBJECTIVE

To identify the different uses and modalities of digital technologies to diagnose, plan and monitor peri-implant soft tissue conditions and aesthetics.

METHODS

A comprehensive narrative review of pertinent literature was conducted, critically appraising key digital technologies that may assist peri-implant soft tissue augmentation and assessment. An electronic search on four databases including studies published prior to 1st July 2023 was performed and supplemented by a manual search.

RESULTS

Predominantly, tools such as cone beam computed tomography (CBCT), intraoral scanning (iOS), intraoral ultrasonography and digital spectrophotometry were commonly to assess and monitor peri-implant soft tissues. The main clinical and research applications included: (i) initial assessment of mucosal thickness, supra-crestal tissue height and keratinized mucosa width, (ii) evaluation of peri-implant soft tissue health and inflammation, (iii) monitoring profilometric changes and midfacial mucosal margin stability over time and (iv) aesthetic evaluation through colour assessment. While evidence for some digital tools may be limited, the integration of digital technologies into peri-implant soft tissue management holds great promise. These technologies offer improved precision, comfort and speed in assessment, benefiting both patients and clinicians.

CONCLUSION

As digital technologies progress, their full potential in peri-implant soft tissue augmentation and their value will become more evident with ongoing research. Embracing these innovations and their potential benefits is recommended to ensure that during progress in implant dentistry, patient care is not hindered.

Randomized controlled pilot study comparing small buccal defects around dental implants treated with a subepithelial connective tissue graft or with guided bone regeneration

AIM

To compare subepithelial connective tissue grafts (SCTG) versus guided bone regeneration (GBR) for the treatment of small peri-implant dehiscence defects in terms of profilometric (primary outcome), clinical, and patient-reported outcome measures (PROMs).

METHODS

Sixteen patients who presented with small buccal bone dehiscences (≤3 mm) following single implant placement were recruited. Following implant placement, buccal bone defect sites were randomly treated either with a SCTG or GBR. Six patients who lacked bone dehiscences after implant placement were assigned to a negative control. Transmucosal healing was applied in all patients. Patients were examined prior (T1) and after (T2) implant placement, at suture removal (T3), at implant impression (T5), at crown delivery (T6), and 12 (T7) months after crown delivery. Measurements included profilometric outcomes, marginal bone levels, buccal bone and soft tissue thickness, PROMs, and clinical parameters. All data were analyzed descriptively.

RESULTS

The median changes in buccal contour as assessed by profilometric measures between T1 and T5 showed a decrease of 1.84 mm for the SCTG group and 1.06 mm for the GBR group. Between T2 and T7, the median change in the buccal contour amounted to 0.45 mm for SCTG and -0.94 mm (=loss) for GBR. Patients' pain perception tended to be higher in SCTG than in GBR. All peri-implant soft tissue parameters showed healthy oral tissues and no clinically relevant differences between groups.

CONCLUSION

Within the limitations of this pilot study, treating small peri-implant dehiscence defects with a SCTG might be a viable alternative to GBR. The use of a SCTG tended to result in more stable profilometric outcomes and comparable clinical outcomes to GBR. However, patient-reported outcome measures tended to favor GBR.

A prospective case series on the efficacy of a cross-linked collagen matrix to increase buccal soft tissue thickness at large edentulous gaps: One-year results

OBJECTIVE

The objective of this study is to assess profilometric changes following soft tissue augmentation with a cross-linked porcine-derived collagen matrix (CMX) at large edentulous gaps of at least two units.

MATERIALS AND METHODS

Systemically healthy, nonsmoking patients with a large edentulous gap of at least two units demonstrating a horizontal soft tissue defect, were enrolled in a prospective case series. Soft tissue augmentation was performed in a one-stage approach with a 6 mm thick CMX at the time of implant placement. The primary outcome was the change in buccal soft tissue profile (BSP) at a mesial, central, and distal area of interest (AOI) up to 1 year when compared to the preoperative situation based on superimposed digital surface models. Secondary outcomes included the horizontal dimension of the soft tissue defect, complications, and marginal bone loss (MBL).

RESULTS

Fifteen patients (eight females; mean age 58.73 years) were enrolled and 13 could be re-assessed at 1-year follow-up. The mean linear increase in BSP at 1 year was 0.66 mm (98.3% CI: 0.37-0.94), 0.80 mm (98.3% CI: 0.39-1.22), and 0.69 mm (98.3% CI: 0.32-1.06) at the mesial, central, and distal AOI, respectively. Substantial shrinkage of about 75% was observed in all areas between augmentation and 1-year follow-up. Even though 11 of 13 sites were fully augmented immediately postoperative, a soft tissue defect recurred in all sites at 1-year follow-up with a mean deficit of 2.30 mm. Altogether, 25% of the original soft tissue defect was eliminated by soft tissue augmentation. CMX was safe since no postoperative complications occurred and MBL was limited (0.70 mm).

CONCLUSION

CMX is efficacious for horizontal soft tissue augmentation at large edentulous gaps. However, considerable graft resorption may be expected, and the clinical relevance of the augmentation may be questionable since all patients demonstrated a recurring and considerable soft tissue defect 1 year after surgery.

Patient-reported outcomes for bone regenerative procedures

Evidence-based dentistry used for decision-making and assessment of treatment includes three components: evidence from the literature, clinical expertise, and patient expectations. Patient satisfaction embraces affability, availability, and ability and can be examined using questionnaires or structured questions to the patient to evaluate patient perception of the treatment. The questions can be quantified using dichotomous, point, or visual analog scales. This would be a straightforward patient-reported outcome measure (PROM). Validated and specific oral health-related quality of life (OHRQoL) questionnaires such as the oral health impact profile (OHIP), oral impact on daily performance (OIDP), or the dental impact on daily living (DIDL) can be used as PROMs, and these measures are appropriate for population studies, where you can measure changes over time and differences between treatment groups. PROMs have shown to enhance patient engagement when integrated into clinical care. PROMs for bone regenerative procedures are mainly used as secondary outcome and are concentrating on the prosthetic outcome more than the pain, discomfort, anxiety, and cost of the surgical procedures. Surprisingly, most patients are satisfied and willing to have the procedures performed again. Whether this is recall bias or not and how the information's from the dentist and the team influence the patients answers to PROMs questionnaires are discussed. The importance of patient perspectives in bone regeneration procedures is obvious and combined with clinical outcome measures, it increases our ability to provide better care. Studies using PROMs as a primary outcome variable are required.

Bone regeneration in implant dentistry: Which are the factors affecting the clinical outcome?

The key factors that are needed for bone regeneration to take place include cells (osteoprogenitor and immune-inflammatory cells), a scaffold (blood clot) that facilitates the deposition of the bone matrix, signaling molecules, blood supply, and mechanical stability. However, even when these principles are met, the overall amount of regenerated bone, its stability over time and the incidence of complications may significantly vary. This manuscript provides a critical review on the main local and systemic factors that may have an impact on bone regeneration, trying to focus, whenever possible, on bone regeneration simultaneous to implant placement to treat bone dehiscence/fenestration defects or for bone contouring. In the future, it is likely that bone tissue engineering will change our approach to bone regeneration in implant dentistry by replacing the current biomaterials with osteoinductive scaffolds combined with cells and mechanical/soluble factors and by employing immunomodulatory materials that can both modulate the immune response and control other bone regeneration processes such as osteogenesis, osteoclastogenesis, or inflammation. However, there are currently important knowledge gaps on the biology of osseous formation and on the factors that can influence it that require further investigation. It is recommended that future studies should combine traditional clinical and radiographic assessments with non-invasive imaging and with patient-reported outcome measures. We also envisage that the integration of multi-omics approaches will help uncover the mechanisms responsible for the variability in regenerative outcomes observed in clinical practice.

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.

Lack of keratinized mucosa increases peri-implantitis risk

DESIGN

A systematic appraisal and statistical aggregation of primary studies in humans.

DATA SOURCES

The researchers utilized PubMed (Medline) and Scopus databases as the primary data sources for this study. They performed a comprehensive literature search based on free keywords and Medical Subject Heading (MeSH) terms to enhance the search accuracy. The database search was concluded on November 13, 2022. Furthermore, a meticulous examination of the references cited in the selected studies was conducted to identify additional relevant articles that could be incorporated into the analysis.

STUDY SELECTION

The systematic review focused on partially or fully edentulous patients receiving dental implants and aimed to determine if the lack of keratinized mucosa at the implant site increased the risk of peri-implantitis compared to patients with adequate keratinized mucosa. Human studies with a minimum of 100 implants, cross-sectional, cohort, or case-control designs, and a follow-up period of at least one year were included. Studies lacking a clear case definition or information on peri-implantitis and those that did not investigate keratinized mucosa as a risk indicator were excluded.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently utilized a systematic review screening website (Rayyan, Qatar Computing Research Institute, Qatar Foundation) to select potential articles, and conflicts were resolved through discussion or consultation with a third reviewer. The data extraction process involved recording information from the included articles, such as study design, patient and implant numbers, prosthesis type (fixed or removable), follow-up duration, peri-implantitis case definition, prevalence at patient and implant levels, keratinized mucosa cutoff value, odds ratio (OR) of peri-implantitis considering keratinized mucosa, and conclusions on the potential effect of keratinized mucosa from each study. The Newcastle Ottawa scale (NOS) and a modified version of NOS were used, respectively, to assess the quality of cohort and cross-sectional studies. Studies scoring below 6 out of 9 points were classified as low quality. For the meta-analysis, the relationship between peri-implantitis and keratinized mucosa was evaluated using the odds ratio (OR) and standard error (SE). Heterogeneity was assessed through the Chi2 test and I2 index, determining whether a random-effects or fixed-effects model should be applied. Subgroup and cluster analyses were conducted based on specific criteria, and forest plots and funnel plots were generated to visualize results and identify potential study bias. Sensitivity analysis was performed to verify the robustness of the meta-analysis, with statistical significance set at p < 0.05. The Review Manager (RevMan) software facilitated data analysis. The GRADE rating system was used to determine the level of evidence, considering factors such as bias risk, imprecision, inconsistency, indirectness, and publication bias. The certainty of the evidence was evaluated based on the overall outcomes of analyzed subgroups.

RESULTS

Twenty-two primary studies were identified, and a meta-analysis was conducted on 16 cross-sectional studies. The prevalence of peri-implantitis ranged from 6.68% to 62.3% at the patient level and from 4.5% to 58.1% at the implant level. The overall analysis revealed a significant association between the lack of keratinized mucosa and a higher prevalence of peri-implantitis (OR = 2.78, 95% CI 2.07-3.74, p < 0.00001). Subgroup analyses with a consistent case definition of peri-implantitis (MBL ≥ 2 mm) showed similar results (OR = 1.96, 95% CI 1.41-2.73, p < 0.0001). Studies focusing on fixed prostheses only demonstrated that the lack of keratinized mucosa was associated with an increased prevalence of peri-implantitis (OR = 2.82, 95% CI 1.85-4.28, p < 0.00001). Among patients under regular implant maintenance, the absence of keratinized mucosa significantly raised the occurrence of peri-implantitis (OR = 2.08, 95% CI 1.41-3.08, p = 0.0002). Studies adjusting for other variables also confirmed a higher risk of peri-implantitis with inadequate keratinized mucosa (OR = 3.68, 95% CI 2.32-5.82, p = 0.007). Although some publication bias was observed, the certainty of evidence based on the GRADE system was judged to be "moderate."

CONCLUSIONS

The lack of keratinized mucosa increased the risk of peri-implantitis, emphasizing the need to consider it during dental implant placement. Inadequate data on patient-specific factors and the predominance of cross-sectional studies influenced the evidence quality (i.e., moderate). Future studies with consistent methodologies shall confirm these findings and identify additional risk indicators to improve implant dentistry practices.

Extraction Socket Augmentation with Autologous Platelet-Rich Fibrin (PRF): The Rationale for Socket Augmentation

After tooth extraction, the alveolar ridge undergoes a physiological process of remodelling and disuse atrophy. Socket augmentation (SA) has been shown to preserve alveolar bone volume in order to facilitate implant placement and reduce the need for staged grafting at a later date. Although autogenic grafting has been shown to be the gold standard in bone regeneration, it has significant disadvantages. To prevent post-extraction volumetric alterations and alveolar bone resorption occurring, alternative grafting materials, including xenografts, alloplasts, and allografts, have been used successfully in fresh extraction sites. However, these materials act mostly as bio-scaffolds and require a slower integration period of 6-8 months prior to implant placement. Recently, the use of autologous platelet-rich fibrin (PRF) has been advocated alongside socket augmentation as a method of bio-enhancement of healing of soft and hard tissues. PRF contains platelet-derived growth factors, hormones, and bioactive components such as cytokines that have been shown to promote angiogenesis and tissue regeneration during wound healing. The aim of this article is to review the evidence base for the SA technique Clinical benefits of SA will be discussed with a reference to two cases. Therefore, this narrative review will discuss the post-extraction bone changes, the importance of SA, and the bio-enhancement role of PRF in the management of extraction site defects when the alternative technique of immediate implant placement is not possible or contraindicated.

Avoiding errors and complications related to immediate implant placement in the esthetic area with a mucogingival approach

Immediate implant placement is considered the treatment of choice for single tooth replacement in the esthetic area. However, this treatment is associated with several critical drawbacks related to the inadequate assessment/management of the soft and hard peri-implant tissues and their subsequent remodeling, resulting in peri-implant soft-tissue defects that can lead to impaired esthetic outcomes in time. We describe in detail how the mucogingival approach to immediate implant placement ensures a standard result regardless of the baseline soft-hard tissue situation. Fully guided implant placement guarantees an adequate three-dimensional implant placement, the flap design makes it possible to perform bone augmentation with complete visibility of the area being treated, allows soft tissue augmentation with proper fixation of the connective tissue graft, and the placement of an immediate provisional ensures stabilization of the peri-implant tissues throughout the healing period.

Buccal bone thickness and mid-facial soft tissue recession after various surgical approaches for immediate implant placement: A systematic review and network meta-analysis of controlled trials

AIM

To evaluate the relative efficacy and confidence in the precision of the results of different surgical interventions for immediate implant placement in the anterior area.

MATERIALS AND METHODS

Electronic searches were performed in PubMed, Embase, and Cochrane CENTRAL. Randomized controlled trials comparing different surgical techniques in anterior jaws for type 1 implant placement were included. Outcome measures included implant survival (primary outcome), buccal bone thickness (BBT) reduction, and mid-facial soft tissue recession (MSTR). Risks of bias assessment, network meta-analysis (NMA), sensitivity analysis, and quality-of-evidence assessment were performed.

RESULTS

Twenty-two studies reporting on 948 subjects and 5 surgical interventions were included. Fourteen early failures were reported. Compared with open-flap surgery without tissue augmentation (F-N) and looking at BBT preservation, NMA showed that there was moderate confidence that flapless surgery with hard tissue augmentation (FL-HTA) was better than flapless surgery without tissue augmentation (FL-N) or open-flap surgery with hard tissue augmentation (F-HTA) (mean difference -0.8 mm, 95% confidence interval: -1.1 to -0.5 mm; -0.6 mm, -0.9 to -0.4 mm; and -0.5 mm, -0.7 to -0.3 mm, respectively). There was moderate confidence that flapless surgery with hard and soft tissue augmentation (FL-HTA&STA) could significantly prevent MSTR compared with FL-HTA (-0.5 mm, -0.7 to -0.3 mm) and FL-N (-0.6 mm, -1.2 to -0.04 mm). However, there was no significant additional benefit in BBT with the FL-HTA&STA approach compared to the FL-HTA approach (-0.30 mm, -0.81 to 0.21 mm).

CONCLUSIONS

For immediate implant placement in the anterior areas, the FL-HTA approach better preserves BBT (moderate confidence); adding STA improves the stability of the mid-facial soft tissue level (moderate confidence) but at the expense of BBT (low confidence).

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.

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.

Surgical interventions for implant placement in the anterior maxilla: A systematic scoping review with evidence mapping

OBJECTIVES

Simplification and standardization of interventions are critical challenges to improving performance in implant dentistry. This study aimed to systematically identify and schematically present the evidence base of the implant dentistry surgical interventions for the anterior maxilla as a basis for further development and standardization.

METHODS

Electronic searches were conducted in PubMed, Embase and Cochrane CENTRAL. Primary clinical studies reporting surgical interventions in the anterior maxilla, with a sample size of at least ten patients, were included. Bibliometric information and study details were extracted. Descriptive analysis and a mind map approach were used to describe the documentation of different surgical interventions.

RESULTS

Two hundred and seventy-two studies reporting on 9001 patients were included. Within the past two decades, the number of literatures on implant placement in the anterior maxilla has increased dramatically (7 studies before 2005, 151 studies after 2016). Overall, the evidence map identified six primary operations and 33 variations. For hopeless tooth extraction, immediate implant placement was the most frequently reported (141 studies, 4670 patients); flapless implant placement with hard tissue augmentation and immediate provisionalization was the most commonly reported variation (33 studies, 987 patients). Type 3/4 implant placement (62 studies, 1902 patients) and implant site augmentation (33 studies, 788 patients) were frequently reported for missing teeth. Geographical differences were observed, with type 2 placement studies almost exclusively from Europe.

CONCLUSIONS

Research on immediate implant placement was the most reported surgical intervention in the anterior maxilla. Hard tissue augmentation was frequently reported simultaneously with or before implant placement. Immediate provisionalization was mainly used for type 1 implant placement. The finding that six primary operations with 33 variations have been reported indicates the need for additional research to simplify and consolidate the surgical approach.

The keratinized mucosa width at partially edentulous molar sites and its associated factors: a pilot study

BACKGROUND

Assessment of the keratinized mucosa width (KMW) at edentulous sites is important for the subsequent implant treatment design. This pilot study aimed to evaluate the characteristics of the KMW at edentulous molar sites and explore the associated factors.

METHODS

A total of 150 patients with 222 edentulous molar sites were included. The buccal KMW of the edentulous molar sites was measured during implant treatment planning. Potentially associated factors, including age, sex, smoking status, location, reasons for tooth loss/extraction, gingival phenotype (GP) and keratinized gingival width (KGW) of the adjacent teeth, were collected and analyzed. The Shapiro‒Wilk test, Student's t test, one-way ANOVA, generalized estimation equations (GEEs) and linear regression analysis were used for data analysis at α = 0.05.

RESULTS

The buccal KMW at edentulous molar sites was 3.97 ± 2.06 mm, and 41.9% of sites presented with KMW < 4 mm. The mean KMWs of the maxillary sites were significantly higher than that those of the mandibular sites (4.96 ± 2.05 mm vs. 3.41 ± 1.85 mm, respectively). In total, 54.7%, 46.5%, 29.8%, and 0.0% of mandibular first and second molar sites and maxillary first and second molar sites, respectively, displayed a KMW of < 4 mm. Statistically significant linear correlations were found between KMW and GP (r = 0.161, p = 0.025) and between KMW and KGW of the adjacent teeth (r = 0.161, p = 0.023), while other factors were found to have no significant association.

CONCLUSION

Within the limitations of the present study, the KMW at edentulous molar site was related to the location of molar tooth loss/extraction. The GP and KGW of the adjacent teeth of edentulous molar sites were also associated with their KMW, which was probably attributed to the continuity of the adjacent soft tissue.

GUIDED PERI-IMPLANT AUTOGENOUS SOFT TISSUE GRAFTING: CASE REPORT

This case report showed the proof-of-concept of a guided free gingival graft around a dental implant. A 65-year-old male presented to replace his 30 and 31. Once the osseointegration of the 2 implants placed by guided surgery has been achieved, a free gingival graft was indicated. The surgical planning of this graft was performed using the Cone Beam Computed Tomography and archs digital scanning already used for implant placement. The greater palatine foramen and gutter were radiologically located to protect their arterial content. Two surgical guides were designed, one for the palatal donor site and one for the recipient site. The first one will serve both as an incision guide and as a post-operative protective plate. The procedure was free of adverse events. At the 1-year recall, the average gain in keratinized tissue width amounted 2.5 mm. This guided surgery could be used in a patient with insufficient amount of keratinized tissue around a posterior implant. For the first time, it makes it possible to anticipate, accelerate and secure the intervention, to improve the practitioner's comfort and potentially the outcomes of free gingival grafts. Further research and clinical are needed to validate this protocol and to assess its long-term impact on peri-implant health.

Annual review of selected scientific literature: A report of the Committee on Scientific Investigation of the American Academy of Restorative Dentistry

The Scientific Investigation Committee of the American Academy of Restorative Dentistry offers this review of the 2021 dental literature in restorative dentistry to inform busy dentists regarding noteworthy scientific and clinical progress over the past year. Each member of the committee brings discipline-specific expertise to coverage of this broad topical area. Specific subject areas addressed, in order of the appearance in this report, include COVID-19 and the dental profession (new); prosthodontics; periodontics, alveolar bone, and peri-implant tissues; implant dentistry; dental materials and therapeutics; occlusion and temporomandibular disorders; sleep-related breathing disorders; oral medicine and oral and maxillofacial surgery; and dental caries and cariology. The authors focused their efforts on reporting information likely to influence daily dental treatment decisions with an emphasis on future trends in dentistry. With the tremendous volume of dentistry and related literature being published daily, this review cannot possibly be comprehensive. Rather, its purpose is to update interested readers and provide important resource material for those interested in pursuing greater details on their own. It remains our intent to assist colleagues in negotiating the extensive volume of important information being published annually. It is our hope that readers find this work useful in successfully managing the patients and dental problems they encounter.

Minimal invasiveness in soft tissue augmentation at dental implants: A systematic review and meta-analysis of patient-reported outcome measures

The aim of this study was to compare patient-reported outcome measures (PROMs) of soft tissue substitutes versus autogenous grafts for soft tissue augmentation procedures at implant sites. Comprehensive and systematic literature searches were performed until December 2021. A focused question was formulated based on the Population, Intervention, Comparison and Outcome criteria (PICO): In patients with dental implants undergoing soft tissue augmentation (P), do soft tissue substitutes (I) compared to autogenous soft tissue graft (SCTG [subepithelial connective tissue graft]) (C) limit the post-operative morbidity and other patient reported-outcomes measures (O). Randomized controlled clinical trials, prospective-, retrospective- and case-series studies were included. Meta-analyses were performed whenever possible and the results were expressed as weighted mean differences (WMD). A total of 29 clinical studies were included. For mucosal thickness gain, soft tissue substitutes significantly reduced the pain perception compared to SCTG (n = 4; WMD = 14.91 Visual Analog Scale [VAS] units; 95% confidence interval [CI] 6.42-23.40; P < .0006) based on a 0-100 VAS scale. Based on a 0-10 VAS scale, a borderline significance of pain reduction was found when soft tissue substitutes were applied (n = 4; WMD = 1.62 VAS units; 95% CI 0.01-3.23; P = .05). For keratinized tissue gain, soft tissue substitutes significantly reduced the pain perception after keratinized tissue augmentation compared to SCTG based on a 0-100 VAS scale (n = 2; WMD = 21.43 VAS units; 95% CI 12.58-30.28; P < .0001). Based on the 0-10 VAS scale, soft tissue substitutes significantly reduced the pain as compared to SCTG (n = 4; WMD = 1.65 VAS units; 95% CI 0.66-2.64; P = .001). Regarding pain medication, soft tissue substitutes required less painkillers (n = 6; WMD = 1.56 tablets; 95% CI 1.22-1.91; P < .00001) after soft tissue augmentation. The surgery time was significantly reduced when soft tissue substitutes were used (n = 5; WMD = 10.9 minutes; 95% CI 4.60-17.19; P < .00001). There were no significant differences in satisfaction, aesthetics, and quality of life (OHIP-14) between soft tissue substitutes and autogenous grafts following soft tissue augmentation at implants sites. Soft tissue substitutes, compared to autogenous grafts, significantly improve PROMs following soft tissue augmentation at implant sites. Soft tissue substitutes can reduce pain perception, amounts of painkillers and surgery time while achieving similar levels of patient´s satisfaction as autogenous grafts without impairing the clinical outcomes. The current evidence indicates that they constitute a valid and reliable alternative to minimize the invasiveness in soft tissue augmentation procedures at implant sites.

A multi-centre randomized controlled trial comparing connective tissue graft with collagen matrix to increase soft tissue thickness at the buccal aspect of single implants: 1-year results

AIM

To compare connective tissue graft (CTG) with collagen matrix (CMX) in terms of increase in buccal soft tissue profile (BSP) at 1 year when applied at single implant sites.

MATERIALS AND METHODS

Patients with a single tooth gap in the anterior maxilla and horizontal mucosa defect were enrolled in a multi-centre RCT. All sites had a bucco-palatal bone dimension of at least 6 mm, received a single implant and an immediate implant restoration using a full digital workflow. Sites were randomly allocated to the control (CTG) or test group (CMX) to increase buccal soft tissue thickness. The primary outcome was the increase in BSP at 1 year when compared to the pre-operative situation based on superimposed digital surface models. The changes in BSP over time were registered at a buccal area of interest reaching from 0.5 mm below the soft tissue margin to 4 mm more apical. Secondary outcomes included patient-reported, clinical and aesthetic outcomes.

RESULTS

Thirty patients were included per group (control: 50% females, mean age 50.1; test: 53% females, mean age 48.2). The increase in BSP at 1 year was 0.98 mm (98.3% CI: 0.75 - 1.20) for CTG and 0.57 mm (98.3% CI: 0.34 - 0.79) for CMX. The mean difference of 0.41 mm (98.3% CI: 0.12 - 0.69) in favour of CTG was significant (p < 0.001). Based on an arbitrarily chosen threshold for success of 0.75 mm increase in BSP, 89.7% of the patients in the control group and 10% of the patients in the test group were successfully treated (OR = 77.90; 95% CI 13.52 - 448.80; p < 0.001). Sites treated with CMX demonstrated 0.89 mm (98.3% CI: 0.49 - 1.30) more shrinkage between postop and 1 year than sites treated with CTG. In addition, CMX resulted in significantly more marginal bone loss (0.39 mm; 95% CI 0.05- 0.74; p = 0.026) than CTG. There were no significant differences between the groups in terms of patients' aesthetic satisfaction (p = 0.938), probing depth (p = 0.917), plaque (p = 0.354), bleeding on probing (p = 0.783), midfacial recession (p = 0.915), Pink Esthetic Score (p = 0.121) and Mucosal Scarring Index (p = 0.965).

CONCLUSION

CTG remains the gold standard to increase soft tissue thickness at implant sites. Clinicians need to outweigh the benefits of CMX against considerable resorption of the graft.

Narrow diameter implants to replace congenital missing maxillary lateral incisors: a 1-year prospective, controlled, clinical study

OBJECTIVES

To report the clinical, radiographic, aesthetic and patient-reported outcomes after placement of a newly developed Narrow-Diameter Implant (NDI) in patients with congenitally Missing Lateral Incisors (MLIs).

MATERIALS AND METHODS

Patients with MLIs with a mesio-distal distance between the canine and the central incisor of 5.9-6.3mm received a dental implant with a diameter of 2.9mm (Test), while a diameter of 3.3mm (Control) was used when the distance was 6.4-7.1mm. After healing, a cement-retained bi-layered zirconia crown was fabricated. At the 1-year follow-up (T2), implant survival rate, marginal Crestal Bone Level (CBL) changes, biological and technical complications were registered. The aesthetic outcome was assessed by using the Copenhagen Index Score, and the patient-reported outcomes were recorded using the OHIP-49 questionnaire.

RESULTS

One-hundred patients rehabilitated with 100 dental implants Ø2.9mm (n = 50) or Ø3.3mm (n = 50) were included. One Ø3.3mm implant was lost and 7 patients dropped out of the study, yielding an implant survival rate of 99% (p = 1.000). At T2 a CBL of -0.19 ± 0.25 mm (Test) and -0.25 ± 0.31 mm (Control) was detected, with no statistically significant difference between the groups (p = 0.342). Good to excellent aesthetic scores (i.e. 1-2) were recorded in most of cases. Technical complications (i.e. loss of retention, abutment fracture, chipping of veneering ceramic) occurred once in three patients with no statistically significant difference between the groups (p > 0.05). OHIP scores did not differ significantly at follow-ups between groups (p = 0.110).

CONCLUSION

The use of Ø2.9mm diameter implants represents as reliable a treatment option as Ø3.3mm implants, in terms of CBL changes, biological and technical complications. Favorable aesthetics and patient-reported outcomes were recorded for both groups.

Soft and hard tissue changes after immediate implant placement with or without a sub-epithelial connective tissue graft: results from a 6-months pilot randomized controlled clinical trial

AIM

The present pilot RCT aimed to investigate the influence of a connective tissue graft (CTG) in combination with the immediate implant placement (IIP) on hard and soft tissues healing, without a bone replacement graft in the gap between the implant and the socket walls.

MATERIAL AND METHODS

Thirty patients requiring extraction of one anterior tooth (from premolar to premolar) were randomly assigned to one of the two treatment groups (test: IIP+CTG; control: IIP). Cone-beam computed tomography (CBCT) and optically scans were performed before tooth extraction and at 6-months follow-up. Then, DICOM files were superimposed in order to allow the evaluation of osseous ridge and buccal bone changes, while the superimposition of DICOM and STL (Standard Tessellation Language) files allowed for evaluating of soft tissue contour. For testing the differences between the two groups, the non-parametric test as Wilcoxon rank-sum test, was used.

RESULTS

Twenty-six out of the thirty enrolled patients, attended the 6-month follow-up visit. The 4 patients of control group that were lost to follow-up, were analyzed under the intention-to-treat principle. No statistically significant differences between the groups were observed for the vertical buccal bone resorption (p=0.90), as well as for the horizontal buccal bone resorption at all measured levels. Significant differences were found between test and control groups in the horizontal dimensional changes of osseous ridge at the most coronal aspect (p=0.0003 and p=0.02). Changes of tissue contour ranged between -0.32 and -0.04 mm in the test group, and between -1.94 and -1.08 mm in the control group, while changes of soft tissue thickness varied between 1.33 and 2.42 mm in the test group, and between -0.16 and 0.88 mm in the control group, with statistically significant differences for both variables at all measured levels. At 6 months, the mean volume increase was 6.76±8.94 mm³ and 0.16±0.42 mm³ in the test and control groups, respectively, with statistically significant difference.

CONCLUSIONS

The findings of the present study indicate that the adjunct of a connective tissue graft at the time of immediate implant placement, without bone grafting, does not influence vertical bone resorption. Within the limits of the present study, it can be suggested that the adjunct of a connective tissue graft at the time of immediate implant placement, without bone grafting, reduces the horizontal changes of the alveolar ridge. Moreover, it allows maintenance of the tissue contour due to an increase in soft tissue thickness.

Profilometric, volumetric, and esthetic analysis of guided bone regeneration with L-shaped collagenated bone substitute and connective tissue graft in the maxillary esthetic zone: A case series with 1-year observational study

PURPOSE

The aim of this study was to evaluate 1-year stability and maintenance of peri-implant soft and hard tissues after guided bone regeneration (GBR) with L-shaped collagenated bone substitute and subepithelial connective tissue graft (CTG) in the maxillary anterior region using profilometric, volumetric, and esthetic analyses.

METHODS

Fourteen peri-implant defects were grafted with L-shaped collagenated bone substitute, and 5 months after implant placement with GBR, reentry surgery in combination with CTG was performed in all participants. CBCT scans and STL files were acquired at baseline (after implant surgery, T1), reentry surgery (T2), and 1-year follow-up (T3). The profilometric and volumetric changes of the peri-implant tissues were measured, and the pink esthetic score (PES) was assessed at T3.

RESULTS

One year after GBR and CTG at the buccal aspect of the maxillary esthetic zone, the mean thickness of the hard tissue (HT) decreased (HT0: -0.87 ± 0.67 mm, HT1: -0.74 ± 0.75 mm, HT2: -0.92 ± 0.48 mm, 45-HT: -0.87 ± 0.73 mm) and the corresponding thickness of the soft tissue (ST) increased (ST0: 0.96 ± 1.06 mm, ST1: 0.85 ± 0.95 mm, ST2: 0.38 ± 0.82 mm, 45-ST: 0.12 ± 0.62 mm), and as a result, there was no statistically significant difference in the total tissue thickness between T1 and T3 (p < 0.05). The mean volumetric changes of the peri-implant tissues increased after 1-year of implant surgery (T1-T2: 1.52 ± 0.83 mm, T2-T3: -0.88 ± 1.04 mm, T1-T3: 0.64 ± 0.90 mm), and a statistically significant difference was shown in all compared time periods (p < 0.05). The mean PES score was 8.07 ± 1.54 at T3 (range, 6-10).

CONCLUSION

Within the limitations of this 1-year follow-up study, GBR with an L-shaped collagenated bone substitute and subepithelial CTG in the maxillary esthetic zone was beneficial for stable and maintainable peri-implant hard and soft tissues.

The role of keratinized mucosa width as a risk factor for peri-implant disease: A systematic review, meta-analysis, and trial sequential analysis

Background

Studies have examined the benefit of having keratinized peri‐implant mucosa width with mixed results.

Purpose

This study examines whether the lack of a prespecified (2 mm) amount of keratinized mucosa width (KMW) is a risk factor for peri‐implant diseases.

Methods

A systematic electronic and manual search of randomized or nonrandomized controlled or noncontrolled clinical trials was conducted. Qualitative review, quantitative meta‐analysis, and trial sequence analysis (TSA) of implants inserted at sites with <2 mm or ≥2 mm of KMW were analyzed to compare all the predetermined outcome variables. The level of evidence concerning the role of KMW in peri‐implant health was evaluated via the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system guide.

Results

Nine studies were included in the qualitative analysis and four in the meta‐analysis and TSA. No significant inter‐group difference (p > 0.05) and a low power of evidence were found for probing depth, soft‐tissue recession, and marginal bone loss. A significant difference favoring ≥2 mm KMW had a lower mean plaque index (MD = 0.37, 95% CI: [0.16, 0.58], p = 0.002) (3 studies, 430 implants, low‐quality evidence). GRADE system showed very low and low quality of evidence for all other outcome measures.

Conclusion

Based on the available studies, the impact of amount of KMW (either <2 mm or ≥ 2 mm) as a risk factor for developing peri‐implant disease remains low. Future control studies with proper sample size and longer follow‐up are needed to further validate current findings.

Implant treatment after traumatic tooth loss: A systematic review

BACKGROUND/AIMS

Treatment after traumatic tooth loss is challenging and is currently guided by expert opinion and the individual patient situation. The aim of this study was to provide an overview on the outcome of dental implant treatment in the anterior maxilla after traumatic tooth loss, based on a systematic review of the existing evidence.

MATERIALS AND METHODS

A systematic search of the literature was performed on PubMed, Cochran Library and Web of Science following the PRISMA guidelines based on a structured research question (PICO). All clinical studies of five patients or more with follow-up of at least 1 year after implant loading were included. Patients were at least 18 years of age. Cohen's Kappa-coefficient was calculated. The Newcastle-Ottawa Scale was applied to assess the quality of the included studies. Descriptive statistical methods were applied.

RESULTS

Nine hundred and ninety-nine articles were identified through the systematic search. Finally, six articles were eligible for inclusion. The studies comprised prospective and retrospective cohort studies and case series. From these, 96 patients with 120 implants were included. The age ranged from 18 to 59 years. The survival rates of implants and superstructures were 97% and 95%, respectively, after a mean follow-up of 3.5 years. Mean marginal bone resorption was 0.56 mm (range 0.21-1.30 mm). Complication rates were 7% and 11% on implant and superstructure level, respectively. Patient-reported outcome measures and objective evaluations showed a high level of satisfaction with the aesthetic outcome. Bone augmentation was performed in 60 implant sites. Three patients underwent pre-surgical orthodontic treatment. The maxillary central incisor was the most frequently replaced tooth (70%).

CONCLUSIONS

This systematic review revealed a low level of evidence on the outcome of dental implant treatment after traumatic tooth loss. Systematic reporting of treatment outcomes of tooth replacements after dental trauma is highly encouraged to further guide dentists for the benefit of these challenging patients.

A multi-centre randomized controlled trial comparing connective tissue graft with collagen matrix to increase soft tissue thickness at the buccal aspect of single implants: 3-month results

AIM

To compare connective tissue graft (CTG) with collagen matrix (CMX) in terms of changes over time in buccal soft tissue profile (BSP) when applied at single implant sites.

MATERIALS AND METHODS

Patients with a single tooth gap in the anterior maxilla and horizontal mucosa defect were enrolled in a multi-centre randomized controlled trial. All sites had a bucco-palatal bone dimension of at least 6 mm and received a single implant and immediate implant restoration using a full digital workflow. Sites were randomly allocated to the control (CTG) or test group (CMX: Geistlich Fibro-Gide®, Geistlich Pharma AG, Wolhusen, Switzerland) to increase buccal soft tissue thickness. Primary outcome was increase in BSP at T1 (immediately after operation) and T2 (3 months) based on superimposed digital surface models. Secondary parameters included patient-reported clinical and aesthetic outcomes.

RESULTS

Thirty patients were included per group (control: 50% females, mean age 50; test: 53% females, mean age 48). Even though surgeons applied thicker grafts when using CMX, sites treated with CMX demonstrated 0.78 mm (95% CI 0.41-1.14) more shrinkage between T1 and T2 than sites treated with CTG. The final increase in BSP was 1.15 mm (95% CI 0.88-1.43) for CTG and 0.85 mm (95% CI 0.58-1.13) for CMX. The mean difference of 0.30 mm (95% CI -0.01 to 0.61) at T2 in favour of CTG was of borderline significance (p = .054). There were no significant differences between the groups in terms of post-operative bleeding (p = .344), pain (p = .331), number of analgesics taken (p = .504), oedema (p = .227), and pink aesthetic score (p = .655). VAS for post-operative haematoma was 6.56 (95% CI 0.54-12.59) lower for CMX, and surgery time could be reduced by 9.03 min (95% CI 7.04-11.03) when applying CMX. However, CMX resulted in significantly more marginal bone loss (0.38 mm; 95% CI 0.15-0.60), deeper pockets (0.30 mm; 95% CI 0.06-0.54), and more mid-facial recession (0.75 mm; 95% CI 0.39-1.12) than CTG.

CONCLUSIONS

CTG remains the gold standard for increasing soft tissue thickness at the buccal aspect of implants.