Wang, Hom-Lay

Purpose: This retrospective study aimed to compare extended sinus lift and extramaxilla surgical protocols for restoring severely atrophic maxillae with zygomatic implants (ZIs) and evaluate their clinical effectiveness. Materials and Methods: The study includes patients who were treated at a dental clinic in Italy from 2012 to 2022. These patients received fixed screw-retained complete dentures supported by either two or four zygomatic implants (ZIs). The patients underwent a minimum one-year follow-up post-loading, following two protocols: the hybrid and the quad protocol. Digital planning incorporated CBCT scans, intraoral scans, and digital prosthetic plans within implant planning software. Surgical techniques involved extended sinus lift and extramaxilla techniques methods, utilizing the ZAGA approach for ZI placement. Results: The results showed that out of 19 patients with a mean age of 65.3, a total of 56 zygomatic implants (ZIs) and 20 standard implants were used, with no failures observed in either the implants or the definitive prostheses, resulting in a 100% survival rate. According to the ORIS criteria, overall success was achieved in terms of implant stability, sinus health, peri-implant soft tissue condition, and prosthetic function. Only two ZIs (3.6%) exhibited minor gingival recession and moderate thread exposure, which were closely monitored through professional hygiene maintenance. Conclusion: Both the extended sinus lift and extramaxilla protocols demonstrated comparable clinical outcomes and minimal complications in the restoration of severely atrophic maxillae with Zygomatic Implants (ZIs). However, further extensive studies involving larger, multicenter designs and longer follow-up periods are needed to validate and refine these outcomes.  Schlagwörter: Zygomatic implants, dental implant loading, immediate, maxillary sinusitis, extreme atrophic maxillae, retrospective study.

This paper introduces the Continuous Crossing Mattress Periosteal Suture Technique (CMPST), designed to enhance flap adaptation, and maintain the established apical displacement of the flap during various periodontal resective surgeries, particularly restorative-driven (or functional) crown lengthening in multiple teeth at anterior or posteriors areas. This suture technique securely positions the flap apically, just coronal to the bone, anchored at the periosteum, combining the advantages of both continuous and cross-compression sutures without compromising the esthetic results. By eliminating flap mobility, it ensures stable and intimate contact with underlying tissues. Further controlled studies are needed to assess the clinical applicability of this technique compared to other suture techniques. Schlagwörter: Suture techniques, crown lengthening, esthetics, prosthodontics

Despite the various barrier membranes proposed, one of the main challenges for guided bone regeneration (GBR) is space maintenance for large defects as well as ensure adequate blood supply. The presented feasibility case series aims to introduce an original titanium frame (TF) design, customized for each defect, as a modification of well-known principles and materials for GBR, for an enhanced and more predictable horizontal and vertical bone augmentation. Three patients with significant horizontal defects were treated with pre-trimmed TFs to create needed space, a 50%-50% mixture of autograft and bovine xenograft was placed, and then covered with collagen membrane. After 8 months of healing, the sites were reopened, the titanium screws were removed with the frame. An average of 8.0 ± 1.0mm horizontal and 3.0 ± 0.0mm vertical bone gain was achieved at the time of re-entry and implant placement surgery. Bone core biopsy was obtained during the implant placement. Histomorphometric analysis revealed that 42.8% of the sample was new vital bone, 18.8% was residual bone graft particles, and 38.4% was bone marrow like structures. After 3-4 months from implant placement, the implants were restored with provisional crowns and then finalized with zirconia screw-retained crowns. This case series suggests that GBR utilizing TFs with or without collagen membranes can be considered a suitable approach for horizontal and vertical bone augmentation. However, based on only three reported cases, the result should be carefully interpreted.

Bone augmentation procedures often leads to coronal displacement of the mucogingival junction, a deficiency of keratinized mucosa, and a reduction in soft tissue height. These challenges complicate the achievement of an ideal peri-implant phenotype. It is known that addressing both the quantity and quality of soft tissue is crucial for the long-term success and aesthetics of implants. This paper introduces a novel technique for peri-implant phenotype modification following bone augmentation, which combines a modified onlay graft (MOG) with an apically positioned flap (APF) performed simultaneously with implant placement. Two clinical cases are presented to demonstrate this approach, highlighting the restoration of the soft tissue environment through a single surgical intervention. The technique resulted in successful outcomes, including increased vestibular depth, keratinized tissue width, and vertical soft tissue volume. The modified onlay graft technique effectively manages soft tissue in post-bone augmentation scenarios, providing an ideal peri-implant phenotype and leading to stable, aesthetic, and functional implant restorations. This method requires fewer surgical interventions than traditional alternatives, minimizing patient discomfort and enhancing overall treatment outcomes. Schlagwörter: Soft tissue augmentation, free gingival graft, peri-implant phenotype, dental implants

Purpose: To systematically analyze the accuracy of autonomous dental implant robotic (ADIR) surgery for dental implant placement. Materials and Methods: PubMed, Embase, and Cochrane CENTRAL were searched on February 21, 2024. Any clinical studies, with the exception of case reports, assessing ADIR accuracy by superimposing preoperative digital planning with postoperative CBCT images were included. The risk of bias was assessed, and a meta-analysis was performed using a random-effect model to evaluate linear and angular deviations between planned and placed implants. Results: Data from six clinical studies reporting ADIR accuracy in 96 patients with 299 dental implants were included (102 implants in 69 partially edentulous patients, 197 implants in 27 complete-arch scenarios). The meta analysis at the implant level reported a mean overall accuracy of ADIR of 0.60 mm (95% CI [0.5133; 0.6965]) at the platform and 0.63 mm (95% CI [0.5663; 0.6909]) at the apex and 1.242 degrees (95% CI [1.2182; 1.6320]) of angular deviation. ADIR accuracy resulted in significantly higher values than static and dynamic computer-assisted implant surgery. Conclusions: Within the limitations of this review, ADIR surgery has shown to be feasible for placing implants in both partially and completely edentulous patients, achieving consistent mean linear and angular deviations of approximately 0.6 mm and 1.40 degrees, respectively. However, clinical practicality of ADIR surgery remains cumbersome, with well-trained operators needed to plan and assist ADIR procedures as well as a technical expert providing backup control.  Schlagwörter: accuracy, autonomous dental implant robotic surgery, dental implant, digital dentistry, implant guides, meta- analysis, robotic surgery

Purpose: This retrospective study investigated the influence of discrepancy in crestal bone height between neighboring implants. Methods: Medical and dental records and periapical radiographs of individuals with at least two adjacent implants were retrieved and analyzed. Records were divided into two groups according to the prosthetic part: non-splinted and splinted groups. Furthermore, groups were categorized by crestal bone height differences between the two adjacent implant platforms into < 0.75mm, 0.76-1.25mm,1.26-1.75, an >1.75mm. Radiographic measurements were performed at 3-time points: time of abutment placement (T0), 1-3 years follow-up (T1), and at the last visit (T2). Multilevel linear regression models using generalized estimating equations were used, with a significance level of 5% (α=0.05). Results: Fifty-six patient records with 120 implants (84 non-splinted (70%) and 36 splinted (30%)) were included. In the non-splinted group, the mean mesial mean bone loss (T2-T0) of the most posteriorly positioned implant was 2.9 mm, 3.1 mm, 3.4 mm, and 3.9 mm across height intervals. The mean distal bone loss of the most anteriorly positioned implant was 3.1 mm, 3.3 mm, 3.4 mm, and 3.9 mm across height intervals. In the splinted group, mean mesial bone loss was 1.1 mm, 2.1 mm, 2.7 mm, and 0.9 mm along different height intervals, while the mean distal bone loss was 1.6 mm, 2.1 mm, 1.6 mm, and 1.3 mm. Results from linear regression showed that non-splinted implants exhibit greater marginal bone loss progression as the vertical difference between adjacent implants increases (p<0.001). The splinted group showed 1.73 mm less bone loss than the non-splinted group at the mesial sides when both had the same CBHL difference (p<0.001) and 1.79 mm more bone loss on the distal side (p<0.001). Conclusions: This study suggests that marginal bone loss progression depends on the difference in crestal height and is aggravated in non splinted implants. Schlagwörter: Dental implants, Dental Prosthesis, Implant-Supported, Alveolar Bone Loss

Purpose: Regenerative hard or soft tissue augmentation procedures (ReP) are crucial in dental implant therapy. This study evaluates the frequency, timing, and financial implication of these procedures before and after implant placement, alongside the influence of systemic conditions on the need for additional interventions. Materials and Methods: This cohort included patients who received implants with or without ReP at the University of Michigan Graduate School of Dentistry from 2011-2023. Data on demographics and systemic health conditions were collected and analyzed using univariable and multivariable logistic regression. Results: 4,803 patients (10,247 implants) were included—48.9% of the patients and 21.7% of the implants received at least one ReP. Ancillary ReP was needed for 14.7% of the implants. The most common of these was alveolar ridge augmentation (ARA) simultaneous with implant placement (42.1%) and alveolar ridge preservation (ARP) (26.4). Diabetics showed significantly higher odds of repeating procedures pre-implant (OR=5.47; p=0.016) and required more frequent hard tissue augmentations post-implant (OR=3.58; p=0.006). Cost analysis revealed that ReP constituted 12.9% of the total implant procedure cost. Notably, the mandibular anterior area was the most likely to undergo ReP (OR=2.08; p=0.001). Conclusions: One of every two patients received a ReP. Almost half of these patients received ARA (simultaneous or staged), and 1/4 received ARP. Diabetic patients exhibited significantly higher odds of requiring hard tissue augmentation pre-IP and post-IP. Trends showed a shift towards soft tissue augmentation over hard tissue procedures for managing peri-implant deficiencies. Schlagwörter: Dental Implants; Regeneration; Alveolar Ridge Augmentation; Costs and Cost Analysis; Prevalence

The reconstruction of interproximal papilla around implants is considered challenging with limited predictability due to the anatomical constraints and reduced blood supply to the interproximal area. This report introduces a minimally invasive tunneling approach, assisted by an operating microscope, to augment interproximal papillae and improve soft tissue contours. Four cases are included: Cases 1 and 2 demonstrate soft tissue grafting around adjacent implants, performed either during the second stage or after provisionalization, while Cases 3 and 4 address implant-pontic scenarios. After conditioning the peri-implant tissues using provisionals, all cases achieved satisfactory outcomes, maintaining stability over a period of six to nine years. The described microsurgical tunnel technique, with the combination of buccal and interproximal subepithelial connective tissue graft, appears to be a promising approach for reconstructing peri-implant papillae with reliable long-term stability. Schlagwörter: dental implants, interproximal papilla reconstruction, connective tissue graft, tunnel technique, soft tissue graft, periodontal plastic surgery, restoration

Successful bone augmentation relies on primary wound closure. Labial frenum is a soft tissue that connects the lip to alveolar mucosa or gingiva. However, frenum may exert biomechanical forces to the wound edge, causing wound instability. The aim of this study is to (1) review the frenum composition and classifications; (2) understand the significance of frenum in wound stability upon bone regeneration. An electronic search was conducted through the three online databases together with manual search on studies published until September 2022. A total of 300 articles were identified and 11 studies were included in this review. Two of the included six studies discovered that 35-37.5% of the labial frenum had muscle fibers. Other studies showed that labial frenum was mainly composed of connective tissue with elastic fibers. There are two widely used classifications for frenum based on morphology and position of attachment. No studies specifically evaluated the impact of frenum on bone regeneration. Frenum location intercorrelated with the amount of keratinized tissue, which could influence wound stability. A modified frenum classification for the edentulous ridge and a decision diagram to manage the frenum is proposed for research and evidenced practice.

Background: It is unclear if single implant vs. two implant-supported mandibular overdentures have similar clinical outcomes especially pertaining to implant survival, marginal bone loss (MBL) and prosthetic complications. A systematic review and metaanalysis of randomized controlled trials (RCTs) was conducted to examine this clinical query. Methods: Main scientific databases (PubMed, Embase, Scopus, Web of Science, and Cochrane Library) were searched from inception until October 6th, 2024, for RCTs comparing single vs two implants for mandibular overdentures and reporting implant failures, MBL and prosthetic complications. Results: Eleven RCTs were included. Meta-analysis showed a tendency of reduced implant failure rates with single implants at 1 year (OR: 0.33 95% CI: 0.10, 1.15 I2=0%) and 5 years (OR: 0.11 95% CI: 0.01, 2.16), but the results were not statistically significant. However, pooled subgroup analysis of studies with a follow-up period of 2-3 years indicated a significantly reduced implant failure rate with one single as compared to two implants (OR: 0.12 95% CI: 0.03, 0.54 I2=0%). No significant differences in implant failure rate were observed between the two groups based on implant loading protocols. Meta-analysis also showed that there were no significant differences in the risk of MBL between single and two implant groups (MD: -0.15 95% CI: -0.31, 0.01 I2=43%). Pooled analysis also showed that the risk of overdenture fracture, relining, and metal housing re-attachment did not differ significantly between single and two implant groups. Conclusions: Evidence from a limited number of RCTs, mainly with small sample sizes, indicates that single implant-supported mandibular overdentures may have a tendency of lower implant failures as compared to two implant-supported mandibular overdentures. The risk of MBL and prosthetic complications may not differ with either treatment modality. Schlagwörter: overdenture; implant survival; marginal bone loss; meta-analysis; mandible