Enhancing guided bone regeneration with cross-linked collagen-conjugated xenogeneic bone blocks and membrane fixation: A preclinical in vivo study.

OBJECTIVE: To determine whether combining cross-linked (CL) collagen-integrated xenogeneic bone blocks stabilized with the fixation of resorbable collagen membranes (CM) can enhance guided bone regeneration (GBR) in the overaugmented calvarial defect model. MATERIALS AND METHODS: Four circular defects with a diameter of 8 mm were prepared in the calvarium of 13 rabbits. Defects were randomly assigned to receive one of the following treatments: (i) non-cross-linked (NCL) porcine-derived collagen-embedded bone block covered by a CM without fixation (NCL + unfix group); (ii) NCL bone block covered by CM with fixation using bone-tack (NCL + fix group); (iii) cross-linked (CL) porcine-derived collagen-embedded bone block covered by CM without fixation (CL + unfix group); and (iv) CL bone block covered by CM with fixation using bone-tack fixation (CL + fix group). The efficacy of GBR was assessed through histological and molecular analyses after 2 and 8 weeks. RESULTS: At 2 weeks, there were no significant differences in histologically measured areas of newly formed bone among the groups. At 8 weeks, however, the CL + fix group exhibited a larger area of new bone (5.08 ± 1.09 mm2, mean ± standard deviation) compared to the NCL + unfix (1.62 ± 0.42 mm2; p < .0083), NCL + fix (3.97 ± 1.39 mm2) and CL + unfix (2.55 ± 1.04 mm2) groups. Additionally, the expression levels of tumour necrosis factor-alpha, fibroblast growth factor-2, vascular endothelial growth factor, osteocalcin and calcitonin receptor were significantly higher in the CL + fix group compared to the other three groups (p < .0083). CONCLUSION: Cross-linked bone blocks stabilized with collagen membrane fixation can significantly enhance GBR.

Immediate loading of definitive restorations in partially edentulous patients requiring an implant-supported prosthesis: A scoping review.

STATEMENT OF PROBLEM: Interest is growing in immediately loading definitive implant-supported prostheses. However, it appears that implant protocols are evolving faster than their scientific validation. PURPOSE: The purpose of this scoping review was to identify the current trends, feasibility, and clinical outcomes of a specific clinical loading scenario (type A), where a single definitive implant-retained restoration is delivered within 3 days. The focus question was "In partially edentulous patients requiring an implant-retained prosthesis (population), is immediate loading with a definitive restoration (concept) a viable treatment option (context)?" MATERIAL AND METHODS: An electronic search was conducted in the PubMed, CENTRAL, Scopus, Embase, and Web of Science databases. Two authors independently reviewed the studies, screened titles and abstracts, and performed full-text analysis. Cross-reference checks within the bibliography of included studies, relevant reviews, and guideline were conducted. Bibliometric information and study details were extracted. RESULTS: The search identified 2568 titles after removing duplicates. Four studies involving 91 participant and 100 implant-retained restorations were included in this scoping review. The selected articles were a randomized controlled trial (RCT), a prospective clinical study, and the remaining 2 were case series. The follow-up periods investigated ranged from 6 to 26 months. All studies evaluated marginal bone loss as a primary outcome, and only 1 implant failure was reported. Patient-reported outcome measures were favorable, and no major biological or technical complications were reported in any study. CONCLUSIONS: Immediate loading with a definitive restoration within 3 days appears to be a suitable approach in specific clinical situations.

Use of optical see-through head-mounted devices in dentistry - a scoping review.

AIM: The aim of this scoping review was to identify the scientific evidence related to the utilization of Optical See- Through Head-Mounted Display (OST-HMD) in dentistry, and to determine future research needs. METHODS: The research question was formulated using the "Population" (P), "Concept" (Cpt), and "Context" (Cxt) framework for scoping reviews. Existing literature was designated as P, OST-HMD as Cpt, and Dentistry as Cxt. An electronic search was conducted in PubMed, Embase, Web of Science, and CENTRAL. Two authors independently screened titles and abstracts and performed the full-text analysis. RESULTS: The search identified 286 titles after removing duplicates. Nine studies, involving 138 participants and 1760 performed tests were included in this scoping review. Seven of the articles were preclinical studies, one was a survey, and one was a clinical trial. The included manuscripts covered various dental fields: three studies in orthodontics, two in oral surgery, two in conservative dentistry, one in general dentistry, and the remaining one in prosthodontics. Five articles focused on educational purposes. Two brands of OST-HMD were used: in eight studies HoloLens Microsoft was used, while Google Glass was utilized in one article. CONCLUSIONS: The overall number of included studies was low; therefore, the available data from this review cannot yet support an evidence-based recommendation for the clinical use of OST-HMDs. However, the existing preclinical data indicate a significant capacity for clinical and educational implementation. Further adoption of these devices will facilitate more reliable and objective quality and performance assessments, as well as more direct comparisons with conventional workflows. More clinical studies must be conducted to substantiate the potential benefits and reliability for patients and clinicians.

Two-step periosteal releasing incision for tension-free flap closure after implant placement with simultaneous guided bone regeneration.

We evaluated the effect of periosteal-releasing incisions on flap displacement in anterior maxillary sites following implant placement and simultaneously guided bone regeneration. Thirty patients requiring a single dental implant and guided bone regeneration in the maxillary esthetic zone were recruited. After full-thickness flap elevation, the displacement of the flap was measured under a standardized tension of 1 Ncm. Then, a two-step periosteal releasing incision was placed in the internal aspect of the flap, and the displacement was remeasured using the same standardized tension. Keratinized tissue width and mucosal thickness at the surgical site were recorded. Patient-reported outcomes were assessed at the 7- and 14-day recall visits. Flap displacement (primary outcome) was calculated before and after periosteal-releasing incisions. Multivariable linear regression models were used to evaluate the influence of mucosal thickness on flap displacement and adjusted for Keratinized tissue width. Primary wound closure was achieved in all patients. The mean difference in flap coronal displacement before and after the periosteal-releasing incisions was 8.2 mm (p<0.0001). Adjusted regression models showed no association between mucosal thickness and keratinized tissue width with the amount of flap displacement (p=0.770). PROMs for pain, swelling, and bleeding amounted to 1.28 ± 1.93, 1.36 ± 1.87, and 0.0 ± 0.0 at seven days and 0.11 ± 0.57, 0.56 ± 1.03, and 0.0 ± 0.0 at 14 days, respectively. Periosteal-releasing incisions using the two-step procedure described here are a predictable technique to obtain coronal flap displacements > 8 mm without increased surgical complications.

The distance of insertion points from wound margins in interrupted and vertical mattress sutures influences the tensile load capacity: An in vitro experimental study.

AIM: To determine the tensile load capacity (TLC) and the tearing characteristics for interrupted and vertical mattress sutures with different insertion points from the wound margin, and the effect of the bite size when using vertical mattress sutures. MATERIALS AND METHODS: A total of 120 gingiva and lining mucosa samples obtained from pig jaws were divided into groups according to the suturing technique (interrupted and vertical mattress sutures), distance of the insertion points from the wound margin (margin, 1, 3, and 5 mm) and bite size (1, 3, and 5 mm). The TLC of the suture and the tearing characteristics were evaluated using a tensile tester device. RESULTS: The TLC was significantly higher for vertical mattress sutures than for interrupted sutures regardless of the distance of the insertion points from the wound margin (intergroup p < .001). This distance significantly influenced the TLC for vertical mattress sutures (p < .05) but not for interrupted sutures (p > .05). Testing the tearing characteristics revealed that no tissue tearing occurred in groups when the insertion points were more than 3 mm from the wound margin. CONCLUSION: The TLC is higher for vertical mattress sutures than for interrupted sutures, and it increases when the insertion points are farther from the wound margin.

Immediate loading on two adjacent single dental implants with definitive nonsplinted restorations: A proof of concept in the posterior zone.

OBJECTIVES: To evaluate clinical, clinician- and patient-reported outcomes (PROs) of two adjacent single posterior implants immediately loaded with definitive single crowns up to 1 year. Ten patients in need of two adjacent posterior single implants were included. All implants were placed applying a fully digital workflow. Definitive screw-retained single zirconia crowns were delivered within 72 h after implant placement. Clinical parameters, patient- and clinician-reported outcomes were assessed up to 1 year of follow-up. CLINICAL CONSIDERATIONS: Clinical outcomes remained stable, with no implant failures or technical and biological complications throughout the observation period. Patient satisfaction was very high at baseline (crown delivery) and remained consistently high at 6 and 12 months of follow-up. Crown insertion 3 days after implant placement was rated as an easy procedure by clinicians. CONCLUSIONS: Two adjacent single implants with immediate definitive restorations (<72 h) in the posterior region appear to be a viable and easy treatment option to shorten the overall treatment time and potentially enhancing patient satisfaction. However, randomized controlled trials are needed to confirm the advantages of this treatment protocol over a delayed loading approach. CLINICAL SIGNIFICANCE: In selected cases, immediate implant loading with definitive restorations in the posterior region appears a valuable and straightforward option to shorten the overall treatment time.

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.

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.

Augmentation of keratinized tissue using autogenous soft-tissue grafts and collagen-based soft-tissue substitutes at teeth and dental implants: Histological findings in a pilot pre-clinical study.

AIM: To histomorphometrically assess three treatment modalities for gaining keratinized tissue (KT) at teeth and at dental implants. MATERIALS AND METHODS: In five dogs, the distal roots of the mandibular second, third and fourth premolars were extracted. Dental implants were placed at the distal root areas 2 months later. After another 2 months, KT augmentation was performed at both distal (implants) and at mesial root (teeth) areas in the presence (wKT groups) or absence (w/oKT groups) of a KT band at the mucosal/gingival level. Three treatment modalities were applied randomly: apically positioned flap only (APF), free gingival grafts (FGGs) and xenogeneic collagen matrices (XCMs). A combination of the above produced six groups. Two months later, tissue sections were harvested and analysed histomorphometrically. RESULTS: The median KT height and length were greatest at implants with FGG in both wKT (3.7 and 5.1 mm, respectively) and w/oKT groups (3.7 and 4.6 mm), and at teeth with FGG in wKT groups (3.7 and 6.1 mm) and with APF in the w/oKT groups (3.9 and 4.4 mm). The XCM and APF produced more favourable results at teeth than at implants. CONCLUSIONS: FGG was advantageous in gaining KT, especially at implants.

The Apical Tooth Replantation with Surgical Intrusion Technique (ATR-SIT) for Regenerative Treatment of Hopeless Teeth: A Report of Two Cases.

The aim of the present clinical report is to introduce a novel surgical procedure, the "Apical Tooth Replantation with Surgical Intrusion Technique" (ATR-SIT) for managing teeth with hopeless prognosis compromised with a severe endodontal-periodontal lesion, pathologic tooth migration, and gingival recession. Two cases are presented managing teeth diagnosed with a hopeless prognosis. ATR-SIT involves tooth extraction, extra-oral root debridement, root surface conditioning, apicectomy, retrograde filling and the application of enamel matrix derivatives prior to reimplantation. Following reimplantation, the teeth are covered with a combination of autogenous bone chips and bone substitute materials, covered with resorbable membranes. Following ATR-SIT, the patients received either orthodontic treatment or tooth-supported fixed dental prostheses. The described ATR-SIT effectively improved the initially hopeless prognosis of the teeth and maintained periodontal health over time, evidenced by favourable clinical and radiographic outcomes. ATR-SIT might be a potential alternative to tooth extraction of hopeless teeth in patients with stage IV periodontitis.

Alveolar ridge changes 1-year after early implant placement, with or without alveolar ridge preservation at single-implant sites in the aesthetic region: A secondary analysis of radiographic and profilometric outcomes from a randomized controlled trial.

OBJECTIVES: To assess both the radiographic and profilometric outcomes of early implant placement with or without alveolar ridge preservation (ARP) (using two different ARP techniques) after 1 year of loading. MATERIALS AND METHODS: Seventy-five patients with a failing single tooth in the anterior maxilla were randomly allocated to three groups (1:1:1): (a) ARP using demineralized bovine bone mineral containing 10% collagen (DBBM-C) covered by a collagen matrix (CM), (b) ARP using DBBM-C covered with a palatal graft (PG), and (c) unassisted socket healing (control). Eight weeks after tooth extraction, early implant placement was performed in all patients. Cone-beam computed tomography (CBCT) and impressions were taken 8 weeks after tooth extraction (ARP/unassisted healing) prior to implant placement and 1-year post-loading. Radiographic and profilometric outcomes were evaluated. RESULTS: Out of the 70 patients available for re-examination at 1-year post-loading, 55 datasets could be assessed (ARP-CM 19; ARP-PG 17; Control 19). The need for additional guided bone regeneration (GBR) at implant placement amounted to 31.6% (ARP-CM), 29.4% (ARP-PG), and 68.4% (unassisted healing). Adjusted models revealed that residual buccal bone height and additional GBR at implant placement significantly influenced the magnitude of the alveolar changes at 1 year (p < 0.05). In patients with ARP (group ARP-CM or ARP-PG) without additional GBR, the presence of bone convexity amounted to 36.0% (9/25) at 1-year post-loading. For patients that received ARP and additional GBR at implant placement, the frequency of bone convexity increased to 72.7% (8/11) (p = 0.042). Regarding profilometric measurements, a tendency toward agreement with radiographic outcomes was observed. CONCLUSIONS: Early implant placement with ARP can attenuate alveolar ridge changes at 1-year post loading by minimizing both radiographic and profilometric alterations. However, early implant placement with simultaneous GBR consistently yields superior radiographic and profilometric outcomes, regardless of whether ARP is performed.

Timing of soft tissue augmentation around implants: A clinical review and decision tree.

PURPOSE: The goal of soft tissue augmentation is to improve the volume around implants and thus achieve better aesthetic and functional properties. The present review aims to make recommendations and guide clinicians in performing soft tissue augmentation procedures, focusing on the importance of timing. OVERVIEW: Soft tissue augmentation can be performed at different time points: before or after implant placement, at implant placement (immediate/delayed), at healing abutment connection or after final restoration. Before/after implant placement or at healing abutment connection are considered the gold standard time points at which to perform soft tissue augmentation due to the possibility of achieving complete coverage of the soft tissue graft or its substitute through simple flap elevation and the easy handling of tissue. On the other hand, performing soft tissue augmentation at implant placement or after crown delivery seems to be less predictable due to the different healing approaches and the unexpected shrinkage that occurs. CONCLUSION: Timing needs to be considered when performing soft tissue augmentation, taking into account the advantages and disadvantages related to operator experience, implant position and patient expectations. Employing a reliable approach at the appropriate time of intervention could limit complications.

Pilot Study: Periosteal Mattress Sutures as an Alternative to Pins and Screws in Guided Bone Regeneration in the Esthetic Zone.

OBJECTIVES: To quantify the buccal bone thickness, area, and perimeter following guided bone regeneration (GBR) using stabilizing periosteal sutures. The loss in hard tissue volume may impair proper implant placement. GBR has been used to regenerate the lost alveolar ridge prior to or at the same time as dental implant placement. The most important factor for GBR success is graft stability. The periosteal mattress suture (PMS) stabilizing technique is an alternative to pins and screws to stabilize bone grafting material and has the advantage of not requiring the removal of the fixing devices. MATERIALS AND METHODS: A CBCT was acquired before and 6 months after surgery from six patients who underwent GBR with the PMS stabilizing technique. Images were analyzed for buccal bone thickness, area, and perimeter. RESULTS: The mean change in buccal bone thickness was 3.42 mm (± 1.31 SD) and proved statistically significant (P = .005). The mean change in bone crest area also proved statistically significant (P = .001). No significant difference was found in bone perimeter (P = .12). CONCLUSIONS: The PMS technique delivered optimal results without clinical complications. This study shows the potential of this technique as an alternative to pins or screws for graft stabilization in the esthetic zone.

Additively and subtractively manufactured implant-supported fixed dental prostheses: A systematic review.

AIM: To compare and report on the performance of implant-supported fixed dental prostheses (iFDPs) fabricated using additive (AM) or subtractive (SM) manufacturing. METHODS: An electronic search was conducted (Medline, Embase, Cochrane Central, Epistemonikos, clinical trials registries) with a focused PICO question: In partially edentulous patients with missing single (or multiple) teeth undergoing dental implant therapy (P), do AM iFDPs (I) compared to SM iFDPs (C) result in improved clinical performance (O)? Included were studies comparing AM to SM iFDPs (randomized clinical trials, prospective/retrospective clinical studies, case series, in vitro studies). RESULTS: Of 2'184 citations, no clinical study met the inclusion criteria, whereas six in vitro studies proved to be eligible. Due to the lack of clinical studies and considerable heterogeneity across the studies, no meta-analysis could be performed. AM iFDPs were made of zirconia and polymers. For SM iFDPs, zirconia, lithium disilicate, resin-modified ceramics and different types of polymer-based materials were used. Performance was evaluated by assessing marginal and internal discrepancies and mechanical properties (fracture loads, bending moments). Three of the included studies examined the marginal and internal discrepancies of interim or definitive iFDPs, while four examined mechanical properties. Based on marginal and internal discrepancies as well as the mechanical properties of AM and SM iFDPs, the studies revealed inconclusive results. CONCLUSION: Despite the development of AM and the comprehensive search, there is very limited data available on the performance of AM iFDPs and their comparison to SM techniques. Therefore, the clinical performance of iFDPs by AM remains to be elucidated.

Epidemiology of mid-buccal gingival recessions according to the 2018 Classification System in South America: Results from two population-based studies.

AIM: The aim of this investigation was to estimate the prevalence, severity and extent of mid-buccal gingival recessions (GRs; classified according to the 2018 Classification System) and to identify their risk indicators in the South American population. MATERIALS AND METHODS: Epidemiological data from two cross-sectional studies-performed on 1070 South American adolescents and 1456 Chilean adults-were obtained. All participants received a full-mouth periodontal examination by calibrated examiners. GR prevalence was defined as the presence of at least one mid-buccal GR ≥ 1 mm. GRs were also categorized into different recession types (RTs) according to the 2018 World Workshop Classification System. Analyses for RT risk indicators were also performed. All analyses were carried out at the participant level. RESULTS: The prevalence of mid-buccal GRs was 14.1% in South American adolescents and 90.9% in Chilean adults. In South American adolescents, the prevalence of RTs was 4.3% for RT1 GRs, 10.7% for RT2 GRs and 1.7% for RT3 GRs. In Chilean adults, the prevalence of RT1 GRs was 0.3%, while the prevalence of RT2 and RT3 GRs was 85.8% and 77.4%, respectively. Full-Mouth Bleeding Score (FMBS; <25%) was associated with the presence of RT1 GRs in adolescents. The risk indicators for RT2/RT3 GRs mainly overlapped with those for periodontitis. CONCLUSIONS: Mid-buccal GRs affected 14.1% of South American adolescents, whereas they affected most of the Chilean adult population (>90%). While RT1 GRs are more commonly observed in a non-representative cohort of South American adolescents (when compared to Chilean adults), the majority of Chilean adults exhibit RT2/RT3 GRs.

Efficacy of a collagen matrix for soft tissue augmentation after implant placement compared to connective tissue grafts: A multicenter, noninferiority, randomized controlled trial.

OBJECTIVES: To test whether soft tissue volume augmentation using a collagen matrix (VCMX) leads to noninferior results in terms of gain of mucosal thickness at single implant sites, compared to connective tissue grafts (SCTG). METHODS: The study was designed as a multi-center randomized controlled clinical trial. Subjects in need of soft tissue volume augmentation at single tooth implant sites were consecutively recruited at nine centers. The deficient mucosal thickness at the implant sites (one per patient) was augmented by applying either a VCMX or a SCTG. Patients were examined at 120 days (abutment connection = primary endpoint), 180 days (final restoration), and 360 days (1-year after insertion of the final restoration). Outcome measures included: transmucosal probing of the mucosal thickness (crestal = primary outcome), profilometric measurements of the tissue volume, and patient-reported outcome measures (PROMs). RESULTS: Out of the 88 patients, 79 attended the one-year follow-up. The median increase of the crestal mucosal thickness between pre-augmentation and 120 days was 0.3 ± 2.1 mm in the VCMX group and 0.8 ± 1.6 mm in the SCTG group (p = .455). Non-inferiority of the VCMX compared to the SCTG was not observed. The respective numbers at the buccal aspect amounted to 0.9 ± 2.0 mm (VCMX) and 1.1 ± 1.4 mm (SCTG; p = .431). PROMs including pain perception favored the VCMX group. CONCLUSION: It remains inconclusive whether soft tissue augmentation using a VCMX is noninferior to SCTG in terms of crestal mucosal thickening at single implant sites. However, the use of collagen matrices favors PROMs especially pain perception, while achieving similar buccal volume gains along with comparable clinical and aesthetic parameters to SCTG.

Dimensional changes after horizontal and vertical guided bone regeneration without membrane fixation using the retentive flap technique: A 1-year retrospective study.

AIM: To evaluate the dimensional changes after horizontal and vertical guided bone regeneration (GBR) without membrane fixation using the retentive flap technique. METHODS: This study retrospectively examined two cohorts that received vertical or horizontal ridge augmentations (VA or HA groups). GBR was performed using particulate bone substitutes and resorbable collagen membranes. The augmented sites were stabilized using the retentive flap technique without any additional membrane fixation. The augmented tissue dimensions were assessed using cone-beam computed tomography at preoperative, immediately postoperative (IP), 4 months (4M), and 1 year (1Y). RESULTS: Postoperative vertical bone gain in 11 participants of VA group amounted to 5.96 ± 1.88 mm at IP, which decreased to 5.53 ± 1.62 at 4M and to 5.26 ± 1.52 mm at 1Y (intragroup p < 0.05). The horizontal bone gain at IP in 12 participants amounted to 3.98 ± 2.06 mm, which decreased to 3.02 ± 2.06 at 4M and to 2.48 ± 2.09 mm at 1Y (intragroup p < 0.05). The mean implant dehiscence defect height after 1Y was 0.19 ± 0.50 mm in the VA group, and 0.57 ± 0.93 mm in the HA group. CONCLUSION: GBR without membrane fixation using the retentive flap technique seems to preserve the radiographic bone dimensions of vertically augmented sites. This technique may be less effective at preserving the width of the augmented tissue.

The 3D emergence profile on implant-supported restorations: A method for evaluating restorative angles.

STATEMENT OF PROBLEM: Emerging evidence indicates that the emergence profile and subsequent restorative angle play a crucial role in clinical outcomes and can potentially affect the development and progression of peri-implant diseases. However, the traditional evaluation of the emergence profile and angle has been limited to mesial and distal sites using periapical x-rays, without considering the buccal sites. PURPOSE: To describe a novel 3D method to estimate the emergence profile and restorative angles around single implant-supported crowns including buccal sites. MATERIALS AND METHODS: A total of 30 implant-supported crowns (11 molars, 8 premolars, 8 central incisors and 1 canine) were extra-orally scanned using an intraoral scanner and the STL files produced were imported into a 3D software. The crown/abutment interface of each crown was delineated, and apico-coronal lines were automatically drawn following the shape of the crown. Three reference points were defined on the apico-coronal lines at the transition edge of the biological (BC) and the esthetic zone (EC) and the resulting angles were then calculated. The reliability of the measurements (2D and 3D) were assessed using the intraclass correlation coefficient (ICC). RESULTS: In anterior restorations, the mean angle of the esthetic zone amounted to 162 ± 14° at mesial sites, to 140 ± 10° at buccal sites and to 163 ± 11° at distal sites. The corresponding angles at the biological zones, amounted to 155 ± 13° at mesial sites, 139 ± 15° at buccal sites and 157 ± 5° at distal sites. In posterior restorations, the mean angle of the esthetic zone amounted to 162 ± 12° at mesial sites, to 157 ± 13 at buccal sites and to 162 ± 11 at distal sites. The corresponding angles at the biological zone, amounted to 158 ± 8 at mesial sites, 150 ± 15° at buccal sites and 156 ± 10 at distal sites. The ICC for all measurements ranged between 0.77 and 0.99 indicating a good intra-examiner reliability. CONCLUSION: Within the limitations of the present study, the 3D analysis seems to be a reliable and applicable method for the quantitative evaluation of the emergence profile in daily practice. Future randomized clinical trials are needed to assess whether a 3D analysis with the ensuing the emergence profile serves as a predictor for clinical outcomes. CLINICAL SIGNIFICANCE: The development and implementation of a 3D workflow will provide technicians and dentists with the ability to assess the restorative angle of implant-supported restorations during the provisional phase and the final restoration. This approach may help achieve an aesthetically pleasing restoration while minimizing potential clinical complications.

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.

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.