Semi-autonomous two-stage dental robotic technique for zygomatic implants: An in vitro study

OBJECTIVE

To assess the feasibility and accuracy of a semi-autonomous two-stage dental robotic technique for zygomatic implants.

METHODS

Twenty-six zygomatic implants were designed and randomly divided into two groups using 10 three-dimensionally printed resin models with severe maxillary atrophy. In one group, the conventional drilling technique was used, in the other group, the drilling process for the alveolar ridge section (first stage) was completed, after which drilling for the zygoma section (second stage) was done. Based on preoperative planning combined with postoperative cone-beam computed tomography (CBCT), coronal, apical, depth, and angle deviations were measured. Zygomatic implant placement technique-related deviations (sinus slot, intrasinus, and extrasinus) were also recorded and analyzed.

RESULTS

The two-stage technical group's coronal, apical, depth, and angle deviations were 0.57 ± 0.19 mm, 1.07 ± 0.48 mm, 0.30 ± 0.38 mm, and 0.91 ± 0.51°, respectively. The accuracy of the two-stage technique was significantly higher than that of the conventional one-stage technique (p < 0.05). The apical deviation in the intrasinus group was 1.12 ± 0.56 mm, which was significantly better than that in the other two groups (p < 0.05). The angle deviation in the sinus slot group was 1.96 ± 0.83°, which was significantly worse than that in the other two groups (p < 0.05).

CONCLUSION

Using the semi-autonomous two-stage dental robotic technique for zygomatic implants is feasible and is more accurate than using the conventional one-stage technique.

CLINICAL SIGNIFICANCE

The two-stage technique enabled the semi-autonomous robot to overcome the mouth-opening restriction for zygomatic implants and improved accuracy.

Comparative evidence of different surgical techniques for the management of vertical alveolar ridge defects in terms of complications and efficacy: A systematic review and network meta-analysis

AIM

To systematically appraise the available evidence on vertical ridge augmentation (VRA) techniques and estimate a treatment-based ranking on the incidence of complications as well as their clinical effectiveness.

MATERIALS AND METHODS

Searches were conducted in six databases to identify randomized clinical trials comparing VRA techniques up to November 2022. The incidence of complications (primary) and of early, major, surgical and intra-operative complications, vertical bone gain (VBG), marginal bone loss, need for additional grafting, implant success/survival, and patient-reported outcome measures (secondary) were chosen as outcomes. Direct and indirect effects and treatment ranking were estimated using Bayesian pair-wise and network meta-analysis (NMA) models.

RESULTS

Thirty-two trials (761 participants and 943 defects) were included. Five NMA models involving nine treatment groups were created: onlay, inlay, dense-polytetrafluoroethylene, expanded-polytetrafluoroethylene, titanium, resorbable membranes, distraction osteogenesis, tissue expansion and short implants. Compared with short implants, statistically significant higher odds ratios of healing complications were confirmed for all groups except those with resorbable membranes (odds ratio 5.4, 95% credible interval 0.92-29.14). The latter group, however, ranked last in clinical VBG.

CONCLUSIONS

VRA techniques achieving greater VBG are also associated with higher incidence of healing complications. Guided bone regeneration techniques using non-resorbable membranes yield the most favourable results in relation to VBG and complications.

Application of Immediate Implant Placement Techniques in Peri-implantitis Modeling

OBJECTIVES

To explore the use of immediate implant placement technique in peri-implantitis modeling, shorten the modeling period, and obtain similar effects.

MATERIALS AND METHODS

Eighty rats were divided into 4 groups: immediate placement (IP), delayed placement (DP), IP-ligation (IP-L) and DP-ligation (DP-L). In the DP and DP-L groups, implants were placed 4 weeks after tooth extraction. In the IP and IP-L groups, implants were placed immediately. Four weeks later, the implants were ligated to induce peri-implantitis in the DP-L and IP-L groups.

RESULTS

Nine implants were lost (3 in the IP-L and 2 each in the IP, DP, and DP-L group). The bone level decreased after ligation, and the buccal and lingual bone levels were lower in IP-L versus DP-L. The implant pullout strength was decreased after ligation. Micro-CT showed bone parameters were decreased after ligation, and the percent bone volume was higher in IP versus DP. Histology showed that the percent of CD4 + cells and IL-17 + cells was increased after ligation and higher in IP-L versus DP-L.

CONCLUSIONS

We successfully introduced immediate implant placement into the modeling of peri-implantitis and observed similar bone resorption and more soft tissue inflammation in a shorter time.

A systematic review of the accuracy of digital surgical guides for dental implantation

PURPOSE

This review aimed to reveal the influence of implant guides on surgical accuracy with regard to supporting types, manufacturing methods and design (including fixation screws and sleeves).

METHODS

A literature search related to accuracy of surgical guides for dental implantation was performed in Web of Science and PubMed. Studies with in vivo or in vitro deviation data published in recent 5 years (2018-2022) were included and assessed by Newcastle-Ottawa Scale with regard to risk of bias and reliability degree of clinical studies. Accuracy-related deviation data were summarized as forest plots and normal distributions.

RESULTS

Forty-one articles were included with high degree of credibility. Data showed that implant surgery accuracy can be achieved with mean distance deviation < 2 mm (most < 1 mm) and angular deviation < 8° (most < 5°).

CONCLUSIONS

Bilateral tooth-supported guides exhibited highest in vitro accuracy and similar in vivo accuracy to unilateral tooth-supported guides; mucosa-supported guides exhibit lowest in vivo accuracy, while its in vitro data showed low credibility due to mechanical complexity of living mucosa tissue. Milling exhibited higher in vivo accuracy of guides than 3d-printing, though further data support was needed. Design of fixation screws and sleeves of implant guides affected the surgical accuracy and might remain a research focus in near future. However, lack of universal evaluation standards for implantation accuracy remained a major problem in this field. The influence of implant guides on surgical accuracy revealed in this review might shed light on future development of dental implantology.

The Custom Alveolar Ridge Splitting (CARS) Technique for Predictable Horizontal Ridge Augmentation in the Atrophic Posterior Mandible: A Case Report

The Custom Alveolar Ridge Splitting (CARS) technique was recently reported as a less-invasive treatment option for augmentation of the maxillary anterior area in cases where alveolar width deficiency exists due to bone resorption and remodeling. This technique creates an intraosseous defect to improve success when horizontal ridge augmentation is attempted. The purpose of the present case report was to demonstrate implant placement in an atrophic posterior mandibular site using the CARS technique. This technique was used in the mandibular right second premolar area, followed by placement of a single implant. The restored implant showed stable soft and hard tissue outcomes at 6 months postloading.

The "Tunneled Sandwich" Technique for Preserving the Buccal Tissue Volume After Immediate Implantation: A Retrospective Report of 10 Cases

Tooth loss or extraction is associated with significant reduction in alveolar ridge volume, extensively expressed in the anterior zone, and immediate implant placement is insufficient to overcome this problem. The proposed approach combined immediate implant placement with buccal tissue enhancement by applying a crosslinked collagen matrix hydrated with crosslinked hyaluronic acid (xHyA). All 10 cases presented with a retained but narrow buccal socket wall, so immediate implant placement with the "tunneled sandwich" technique was performed after tooth extraction. The tunneled sandwich technique helped create a subperiosteal pouch for insertion of the collagen matrix buccal to the alveolar bone crest. The implants healed transmucosally by receiving either a gingiva former or an immediate temporary restoration. Ten sites in 10 patients demonstrated stable, noninflamed peri-implant conditions and suitable ridge volume at the implant neck and achieved high pink esthetic scores 6 months after implant loading. The tunneled sandwich technique is a suitable method to preserve buccal volume, which biologically and esthetically contributes to favorable long-term results.

Digital design and manufacture of a stackable implant surgical guide for immediate loading in completely edentulous full-arch cases: a dental technique

The design and manufacture of a stackable surgical guide for implant placement with immediate prosthetic loading of completely edentulous cases is described in this dental technique. To achieve this, the stackable attachment is designed using free-form designing software, which is later joined to the implant placement guide and the dental prosthesis. This technique should provide the patient with a same-day implant and an esthetic restoration accurately placed in the predesigned position of the centric occluding relationship. It also reduces the number of visits and prosthetic complications related to the improper implant position.

How to Prevent and Manage Postoperative Complications in Maxillary Sinus Augmentation Using the Lateral Approach: A Review

Maxillary sinus augmentation with a lateral approach is known to present more postoperative complications than other atrophic posterior maxilla treatment modalities because it is more invasive. These complications include infections that occur in the form of chronic or acute sinusitis. According to the literature, the frequency of these complications ranges from 3% to 5%. They can result from an inadequate management of intraoperative complications or from a poor evaluation of maxillary sinus particularities and pathology before the surgery. Therefore, the prevention of postoperative complications lies in the selection of cases that will allow for the identification and evaluation of infectious risk. Only a multidisciplinary approach that includes an implantologist, a rhinologist, and the treating physician will allow this. On the other hand, in infectious complication cases, the intervention of the otorhinolaryngologist (ENT) specialist is necessary. Based on the available literature and the author's experience, the methodology described in this article will allow for the prevention and management of postoperative complications related to this surgical technique.

Peri-implant Outcomes from Customized Healing Abutments Using Immediate Implants: A Systematic Review

PURPOSE

To evaluate the peri-implant outcomes of customized healing abutments (CstHA) placed on dental implants inserted in fresh tooth extraction sockets.

MATERIALS AND METHODS

The study was registered on PROSPERO: CRD42022304320. A systematic search in PubMed, Scopus, and Web of Science was conducted between April 2022 and October 2022 to identify clinical studies involving immediate implant surgery associated with CstHA placement. The Joanna Briggs Institute Critical Appraisal and RoB2 tool were performed for the risk of bias analysis.

RESULTS

A total of 12 studies were included, most of them with low risk of bias. Four studies compared CstHA vs conventional healing abutments (CnvtHA), two compared CstHA vs cover screw and collagen matrix (CMa), and six were clinical case series. For the CstHA vs CnvtHA comparison, favorable results were observed for CstHA considering papilla maintenance and probing depth, yet the mean marginal bone level was statistically similar between CstHA and CnvtHA. CstHA showed advantages when compared to CMa for total bone volume, papilla height, and midfacial mucosa maintenance. Significantly less horizonal bone loss was reported when using CstHA compared with CMa. Horizontal and vertical bone loss was observed in a few (or no) sites in the case series using CstHA.

CONCLUSIONS

CstHA provides favorable peri-implant response because in general it does not result in a significant loss of soft and hard tissues.

Technique-Related Survival Rate and Complications of Zygomatic Implant Placement: A Systematic Review and Meta-Analysis

PURPOSE

To assess the survival rate (SR) and probability of postoperative complications at both the implant and patient level for each of the four surgical techniques for zygomatic implant (ZI) placement: Brånemark, sinus slot, extrasinus, and extramaxillary.

MATERIALS AND METHODS

A systematic literature review and meta-analysis of clinical studies that reported the survival rate and postoperative ZI complications for the rehabilitation of atrophic edentulous maxillae was conducted based on PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) recommendations. Two independent reviewers consulted four databases during the literature search: MEDLINE (PubMed), Google Scholar, Clinicaltrials.gov, and LILACS. Duplicate articles were eliminated.

RESULTS

A total of 35 studies were included in the meta-analysis. Subgroup analysis showed that study design (prospective vs retrospective) had no significant impact (P = .10) on the outcomes. The SR was highest for the Brånemark and extrasinus techniques (100%) and lowest for the sinus slot technique (94%; 95% CI = 86% to 102%). The extramaxillary (38%; 95% CI = 1% to 3%) and the Brånemark (29%; 95% CI = 15% to 44%) techniques resulted in the highest occurrence of patient-level complications. Moreover, the extramaxillary technique showed the highest percentage of prothesis-related complications (44%; 95% CI = 27% to 62%).

CONCLUSIONS

ZI placement was demonstrated to be a reliable technique for the rehabilitation of severely atrophic maxillae, irrespective of the surgical technique evaluated. Accurate case and surgical protocol selection is of paramount importance to reduce technique-related postoperative complications.

Extra-Short 4-mm Implants Splinted to 10-mm Implants in the Posterior Maxilla: 3-year Results

PURPOSE

To evaluate the 3-year success and survival rates of fixed prostheses supported by 4-mm extra-short implants splinted to 10-mm implants in patients with shortened maxillary arches and low maxillary sinus floors.

METHODS

A total of 11 patients with reduced alveolar bone heights due to low maxillary sinus floors received two or three titanium-zirconium tissue-level implants: one or two extra-short (4 mm) implants, and one implant 10 mm in length. After 6 months, prosthetic rehabilitation with splinted crowns connecting the 4- and 10-mm implants was performed. Follow-up visits and maintenance protocols were implemented every 4 to 6 months.

RESULTS

The 11 patients were treated with 11 10-mm implants and 17 4-mm implants. One extra-short implant failed and was removed before loading, and its planned design was modified from three splinted crowns to a bridge between the 10- and 4-mm implants. After 36 months, all (11/11) prosthetic rehabilitations connecting the 10-mm (11/11) and 4-mm (16/16) implants were functional. At the 10-mm implant sites, the median (interquartile range [IQR]) probing depth and marginal bone loss measured 2.9 mm (2.3 to 3.2) and 1.3 mm (1.0 to 1.5), respectively. At the 4-mm implant sites, the median (IQR) probing depth and marginal bone loss measured 2.9 mm (2.4 to 3.1) and 0.3 mm (0.1 to 0.5), respectively.

CONCLUSION

Prosthetic rehabilitation with splinted crowns connecting 4-mm and 10-mm implants showed promising outcomes in shortened maxillary dental arches after 3 years. Additional studies are needed to further validate these findings.

Implant Survival Rate in Mandible Reconstructed with Free Fibula Flaps After Oral Tumors: A Systematic Review and Meta-Analysis

PURPOSE

To assess the implant survival rate in mandibles reconstructed with free fibula flap after oral tumor resection after 1 year of prosthetic loading. A secondary objective was to compare immediate or delayed implant placement protocols in this population.

MATERIALS AND METHODS

Electronic and manual searches were performed on different databases for controlled and prospective trials that indicated implant survival rate. This systematic review followed PRISMA guidelines. Risk of bias was evaluated using Cochrane Collaboration tools. Meta-analyses heterogeneity source assessment and GRADE evaluation were performed among studies with identical follow-ups.

RESULTS

Among 305 primarily selected articles, 109 were eligible after reading the title and abstract, and 8 were included after full-text reading: 2 randomized controlled trials and 6 prospective studies comprising 140 patients and 507 implants. Meta-analyses estimated an overall survival rate of 97% (95% CI: 94% to 99%) after 1 year of prosthetic loading. The survival rate was 98% (95% CI: 94% to 100%) with immediate implantation and 97% (95% CI: 90% to 99%) with delayed implantation. Only 3 studies reported radiotherapy treatment, with no real impact on implant survival rate. Overall, 69% of tumors were benign.

CONCLUSIONS

Implant placement in vascularized fibula flaps in the mandible is recommended for patients undergoing segmental mandibular reconstruction after tumor resection. Within the limitations of this study, no significant difference in survival rates was found between immediate and delayed implant placement.

Clinical and Radiographic Outcomes of a New Fully Tapered Implant with the One-Abutment One-Time Approach: In-Line Clinical Case Series with a 1-Year Follow-up

PURPOSE

To evaluate the bone level changes in a new implant design (fully tapered with platform switching) with the one-abutment one-time protocol after 1 year of loading.

MATERIALS AND METHODS

Thirty patients received 1 or 2 implants (6-, 8-, or 10-mm length and 3.5-, 3.75-, or 4.5-mm diameter, bone-level design) to replace one or multiple edentulous sites. Only the mesial implant was assessed. Radiographic, clinical, and esthetic results and the survival and success rates were evaluated 1 year after final loading.

RESULTS

At 1 year, no peri-implant bone loss was seen in any of the cases. Mean marginal crestal bone loss between surgery and crown placement was 0.19 ± 0.17 mm (P < .0001). Between surgery and the 1-year follow-up, the mean marginal crestal bone loss was 0.25 ± 0.24 mm (P < .0001). The difference in the modified Plaque Index between 1 year of follow-up and crown placement was significant for in the mesial (0.33 ± 0.54 mm; P = .003) and distal surfaces (0.5 ± 0.73 mm; P = .001). The probing pocket depth was statistically significantly deeper at 1 year than at crown placement at the mesial and distal aspects (average depth = 0.75 mm; P < .0005). No statistically significant differences were found for any other clinical or esthetic parameters. The overall survival and success rates after 1 year were 100%.

CONCLUSIONS

The fully tapered, deep-thread, platform-switched implant design placed with the one-abutment one-time protocol demonstrated minimal marginal crestal bone loss and crestal bone stability at 1 year of follow-up.

A systematic review on removal of osseointegrated implants: un update

BACKGROUND

Today dental implants represent an effective therapy in case of partial or total edentulism, with an excellent success rate. Despite the results obtained, there may be biological or mechanical complications during the therapy, which lead to the loss of the implant. This systematic review aims to evaluate the current state of the art in the literature on techniques used for the removal of dental implants. Various aspects will be analyzed, such as the success of the technique, any complications, and the advantages and disadvantages of their use.

METHODS

Two reviewers conducted a literature analysis (PubMed, Embase, Web of Science) of the last 20 years (2003-2023). The main criterion analyzed was the success of the technique, while secondary outcomes such as complications and risks of the technique were also analyzed. 258 articles were identified in the various search databases. 42 eligible articles were subsequently identified after an article screening. Only 18 full texts were subsequently included in the review.

RESULTS

A total of 18 articles were selected and 1142 implants and 595 patients were included. The main techniques used were the Counter-Torque Ratchet Technique (CTRT), Piezoelectric bone surgery (PBS), trephine drills, carbide burs, Erbium, Chromium, Yttrium, Scandium, Gallium, Garnett (Er:Cr:YSGG) laser and carbon dioxide (CO2) laser. Combined uses of techniques have been identified such as: PBS and trephine burs or carbide burs, trephine burs with the use of a 3d-printed guide, CTRT and trephine burs. The technique with the highest success rate, less morbidity for the patient, and less removal of bone appears to be the CTRT.

CONCLUSIONS

The use of conservative techniques, especially CTRT, in bone removal is useful to allow for immediate implant placement in the removal area. However, further studies with a high sample size are needed to be performed on all techniques, particularly new randomized controlled trials (RCTs) that allow for the analysis of the success of alternative techniques such as Laser and Piezosurgery, which appear to be very promising.

[Observation on the effect of plasmatrix bone block applied on alveolar horizontal bone augmentation]

A retrospective case series was used to evaluate the effect of plasmatrix bone blocks on bone augmentation at the level of the alveolar ridge. From January 2021 to April 2022, a total of 25 patients who underwent horizontal alveolar ridge level bone augmentation in the Department of Implantology, Wuhan Dazhong Stomatological Hospital were included. Autologous bone chips, deproteinized bovine bone matrix and plasma matrix were used to make plasma matrix bone blocks, combined with absorbable collagen membrane and plasma matrix membrane for guided bone regeneration. Three-dimensional reconstruction was performed on the cone beam CT data before operation and 6 months after operation, and the bone width and alveolar bone volume at 2 and 8 mm from the alveolar crest were measured. The paired t test was used to compare the differences between two time points of the same measurement item. The results showed that compared with preoperative [(5.5±3.4) mm] bone width, the bone width [(9.5±2.5) mm] at 2 mm from the alveolar crest was significantly increased at 6 months after operation (t=3.40, P˂0.001); there was no significant difference in the bone width at the level of 8 mm from the alveolar crest between pre-and 6 months post-operation (t=3.13, P=0.050). The volumes of alveolar bone at 2 and 8 mm from the alveolar crest were (5 114±3 883) and (3 329±2 874) mm3 before operation, respectively, and these increased significantly to (5 999±4 318) and (4 042±3 260) mm3 (t=5.69, P˂0.001; t=5.689, P˂0.001) 6 month post-operation. The results from this study has shown that the use of plasmatrix bone blocks+absorbable collagen membrane+plasma matrix membrane for horizontal bone augmentation in guided bone regeneration has a promising bone augmentation outcome.

[Accuracy evaluation of static guided implant placement using an intraoral scan method]

PURPOSE

To evaluate the accuracy of static guided implant placement with intraoral scanning technology and to analyze the influencing factors of guided surgery.

METHODS

Totally 27 cases were included in this retrospective study. The implant designs were made in 3Shape Implant Studio and then guided implant surgeries were performed with CAD-CAM templates. Postoperative implant positions were detected with an intraoral scanner (3Shape TRIOS) and deviation of implantation was evaluated using established CAD/CAM based evaluation method. SAS 9.4 software package was used for data analysis.

RESULTS

The mean deviation of entrance point and apical point was (1.182±0.609) mm and (1.658±0.741) mm, respectively. Angular deviation was (5.712±3.347)°. Implant quadrant, location of the implant site, guidance degree, supporting type and implant size influenced direction deviation, while angular deviation was mainly affected by guidance degree and number of missing teeth.

CONCLUSIONS

Accuracy of static guided implant placement can be influenced by many factors. More research is needed to improve the accuracy of static guided implantation.

Fabrication of a Dual-Purpose Implant Surgical Guide

While surgical guides have allowed for more highly accurate immediate implant placement in the esthetic zone, only a few techniques have been described to predictably position an immediate implant provisional. Even fewer techniques have addressed repositioning a patient's extracted tooth for use as the interim implant restoration. This article describes a workflow for the fabrication of a dual-purpose surgical guide that allows for guidance of implant placement as well as repositioning of a decoronated tooth that will serve as a provisional. While other provisional techniques aim to recreate proper gingival contour, the benefit of repositioning of the original tooth is the preservation of the existing gingival margin position and existing critical contour of the emergence profile.

Simultaneous or staged lateral ridge augmentation: A clinical guideline on the decision-making process

Lateral ridge augmentation is a standard surgical procedure that can be performed prior to (staged) or simultaneously with implant placement. The decision between a simultaneous or staged approach involves considering multiple variables. This paper proposed a decision-making process that serves as a guideline for choosing the best treatment choice based on the available evidence and the author's clinical experience.

Clinical decision and related factors influencing implant direction in the esthetic area

Implant treatment in the esthetic area requires stable osseointegration and successful esthetic outcomes. Achieving this goal requires careful consideration of accurate implant axis and ideal three-dimensional position. Owing to the high esthetics and the special anatomical structure of the maxillary, a successful implant means a synthesized deli-beration of the residual bone dimensions, soft-tissue thickness, and the relationship of the residual alveolar ridge with the planned restoration. This article offers an in-depth analysis of the clinical decisions and key factors affecting the implant direction in the esthetic area.

Sinus floor augmentation using crestal approach in conjunction with hydroxyapatite/cross-linked collagen sponge: A pilot study

BACKGROUND

Different biomaterials were suggested for sinus floor augmentation (SFA). Recently, new materials were launched showing true bone formation without remnants.

PURPOSE

The aim of this prospective study was to evaluate an hydroxyapatite-based, sugar cross-linked collagen sponge (OSSIX™ Bone) in transcrestal SFA (t-SFA).

MATERIALS AND METHODS

Twenty-four patients with edentulous posterior maxilla and residual bone height (RBH) >4 mm underwent t-SFA with OSSIX™ Bone as grafting material and simultaneous implant placement. The implant Stability Quotient (ISQ) was measured by resonance frequency analysis (RFA) directly after implant insertion and at 6 months. Differences in bone height (BH) and volume were determined in CBCT and x-rays at baseline versus 1 year of follow-up. Graft volume was evaluated by tridimensional reconstructions. Linear regression analysis was used to evaluate the effect of bucco-palatal sinus dimension, RBH, and length of the implant protruding (PIL) into the sinus, on the graft height (GH) changes up to 1 year, and on the graft volume at 1 year. Autocorrelation between time lag and augmented bone volume was evaluated through time series analysis correlograms. Health-related quality-of-life outcomes were captured.

RESULTS

Twenty-two patients completed the study. The mean RBH measured at baseline was 5.81 ± 2.2 mm. The mean graft volume was 1085.8 ± 733.4 mm3 . The mean GH, measured in the immediate post-operative period, at 6 and 12 months respectively, was 7.24 mm ±1.94; 6.57 mm ± 2.30; 5.46 mm ± 2.04. The mean ISQ measured after the implant placement was 62.19 ± 8.09, and 6 months later was 76.91 ± 4.50. There was a significant correlation between buccolingual dimension and graft volume at 1 year. Neither buccolingual volume nor RBH had a significant effect on GH change, while the PIL showed a significant positive correlation (P = 0.02 and P = 0.03 at 6 and 12 months, respectively). The correlograms indicated no significant correlation, meaning that there is no tendency for graft volume to increase or decrease over time, therefore suggesting graft stability, at least up to one year of follow-up. 86% of patients had no chewing interference.

CONCLUSION

Within the limitations of the study, OSSIX™ Bone could be considered a valid material for SFA due to its manageability and its positive results in promoting new bone formation with long-term stability. T-SFA is confirmed as a less invasive and less painful method.

Efficacy of biomaterials for lateral bone augmentation performed with guided bone regeneration. A network meta-analysis

Bone regeneration is often required concomitant with implant placement to treat a bone fenestration, a dehiscence, and for contouring. This systematic review assessed the impact of different biomaterials employed for guided bone regeneration (GBR) simultaneous to implant placement on the stability of radiographic peri-implant bone levels at ≥12 months of follow-up (focused question 1), as well as on bone defect dimension (width/height) changes at re-assessment after ≥4 months (focused question 2). Only randomized controlled trials (RCTs) and controlled clinical trials (CCTs) that compared different biomaterials for GBR were considered. A Bayesian network meta-analysis (NMA) was performed using a random-effects model. A ranking probability between treatments was obtained, as well as an estimation of the surface under the cumulative ranking value (SUCRA). Overall, whenever the biological principle of GBR was followed, regeneration occurred in a predictable way, irrespective of the type of biomaterial used. A lower efficacy of GBR treatments was suggested for initially large defects, despite the trend did not reach statistical significance. Regardless of the biomaterial employed, a certain resorption of the augmented bone was observed overtime. While GBR was shown to be a safe and predictable treatment, several complications (including exposure, infection, and soft tissue dehiscence) were reported, which tend to be higher when using cross-linked collagen membranes.

Membrane barriers for guided bone regeneration: An overview of available biomaterials

Dental implants revolutionized the treatment options for restoring form, function, and esthetics when one or more teeth are missing. At sites of insufficient bone, guided bone regeneration (GBR) is performed either prior to or in conjunction with implant placement to achieve a three-dimensional prosthetic-driven implant position. To date, GBR is well documented, widely used, and constitutes a predictable and successful approach for lateral and vertical bone augmentation of atrophic ridges. Evidence suggests that the use of barrier membranes maintains the major biological principles of GBR. Since the material used to construct barrier membranes ultimately dictates its characteristics and its ability to maintain the biological principles of GBR, several materials have been used over time. This review, summarizes the evolution of barrier membranes, focusing on the characteristics, advantages, and disadvantages of available occlusive barrier membranes and presents results of updated meta-analyses focusing on the effects of these membranes on the overall outcome.

Critical review on bone grafting during immediate implant placement

In the last 20 years, immediate implant placement has been proposed as a predictable protocol to replace failing teeth. The research conducted in preclinical and clinical studies have focused on soft and hard tissue changes following tooth extraction and immediate implant placement. Different approaches for hard and soft tissue grafting together with provisional restorations have been proposed to compensate tissue alterations. This review analyzed some relevant clinical and preclinical literature focusing on the impact of bone grafting procedures on immediate implant placement in terms of hard and soft tissue changes, aesthetic results, and patient-related outcomes.

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.

Comparison of osteogenesis and osseointegration following implant placement with simultaneous maxillary sinus augmentation using particulate and collagenated block types of deproteinized porcine bone mineral: a radiographic and histomorphometric analysis

OBJECTIVES

This study aimed to compare osseointegration and osteogenesis after single-stage maxillary sinus augmentation with the lateral window using particulate deproteinized porcine bone mineral (PDPBM) and collagenated block deproteinized porcine bone mineral (BDPBM).

MATERIALS AND METHODS

Bi-maxillary premolars of six beagle dogs were extracted. Eight weeks later, an implant was placed into each augmented sinus with PDPBM or BDPBM according to a split-mouth design. Eight weeks later, all specimens were harvested. Each specimen was separated into the region of interest with the implant (ROI-I) and region of interest with sinus augmented area (ROI-S) 5 mm away from ROI-I. ROI-I and ROI-S were evaluated through micro-computed tomography and histomorphometry.

RESULTS

Bone substitute insertion took longer for the PDPBM group than for the BDPBM group (P = 0.002). In ROI-I, three-dimensional bone-to-implant contact (BIC) did not show statistically significant differences between the groups. Two-dimensional BIC also showed comparable values for both groups. In ROI-S, the graft material volume/tissue volume, trabecular bone pattern factor, and structural model index were higher in the BDPBM group than in the PDPBM group (P < 0.05). The proportions of new bone, graft material, and connective tissue were not significantly statistically different between groups. Less new bone was found in the apical area than in the coronal or middle areas in the BCPBM group (P < 0.05).

CONCLUSIONS

BDPBM may save time in inserting bone substitutes and provide comparable osteogenesis and osseointegration to PDPBM.

CLINICAL RELEVANCE

When performing sinus augmentation, BDPBM might improve operator's convenience with comparable biological results compared to PDPBM.

The importance of soft tissue condition in bone regenerative procedures to ensure long-term peri-implant health

Bone regenerative procedures have been widely proved to be a reliable treatment option to re-create the ideal pre-implant clinical conditions. Nevertheless, these techniques are not free from post-operative complications which might result in implant failure. Consequently, as demonstrated by the increasing recently published evidence, a careful pre- and intra-operative flap evaluation to ensure an ideal and hermetic tension-free wound closure is of paramount importance to successfully treat bony defects. In this respect, several surgical interventions mainly aimed to increase the amount of keratinized mucosa either to allow an optimal healing after a reconstructive procedure or to establish an optimal peri-implant soft tissue seal have been proposed. The present review summarizes the level of evidence on the surgical clinical aspects which have an impact on the soft tissue handling associated with bone reconstructive procedures and on the importance of soft tissue conditions to enhance and maintain peri-implant health in the long-term.

Indications and surgical technique for distraction osteogenesis of the alveolar bone for augmentation prior to insertion of dental implants

When bone is limited, short, ultra-short, or narrow implants help to restore oral rehabilitation with an acceptable long-term outcome. This becomes more difficult with severe vertical bone loss. Guided bone regeneration, onlay block transplantation, or sandwich osteotomy have been established to build up these defects. The alternative to the alveolar distraction osteogenesis (ADO) has only been established in some centers, with a standardized protocol. On the one hand, ADO is a biological procedure that allows almost a "restitutio ad integrum" when building up hard and soft tissue. On the other hand, there are clear indications, limitations, and complications of the procedure in the literature. In addition to the literature, concept of Tissue Regeneration by Alveolar Callusdistraction Cologne (TRACC), which has been practiced successfully for over two decades, will be presented for different indications.

Techniques on vertical ridge augmentation: Indications and effectiveness

Vertical ridge augmentation techniques have been advocated to enable restoring function and esthetics by means of implant-supported rehabilitation. There are three major modalities. The first is guided bone regeneration, based on the principle of compartmentalization by means of using a barrier membrane, which has been demonstrated to be technically demanding with regard to soft tissue management. This requisite is also applicable in the case of the second modality of bone block grafts. Nonetheless, space creation and maintenance are provided by the solid nature of the graft. The third modality of distraction osteogenesis is also a valid and faster approach. Nonetheless, owing to this technique's inherent shortcomings, this method is currently deprecated. The purpose of this review is to shed light on the state-of-the-art of the different modalities described for vertical ridge augmentation, including the indications, the step-by-step approach, and the effectiveness.

Clinical and radiographic results of crestal vs. subcrestal placement of implants in posterior areas: A split-mouth randomized controlled clinical trial

OBJECTIVE

The objective of this study was to evaluate the peri-implant soft tissue and marginal bone loss (MBL) around implants with platform-switching and internal conical connection placed at crestal and subcrestal levels in posterior areas.

MATERIALS AND METHODS

Nineteen partially edentulous patients with at least two adjacent missing teeth in posterior areas unilaterally or bilaterally were included. Forty-two implants were placed randomly at the crestal or subcrestal (1 mm) level in a split-mouth design. Implant-supported fixed dental prostheses with screw retention were delivered after 4 months of healing. Clinical and radiological measurements were performed at implant placement (T0), restoration delivery (T1), and 1-year follow-up after loading (T2). MBL was calculated as the change in distance from the implant-abutment interface to the first radiographically visible bone-implant contact. A repeated-measures mixed ANOVA followed by a paired Student's t-test with the Bonferroni correction was used for statistical analysis. p < 0.05 was considered statistically significant.

RESULTS

Eighteen patients with thirty-eight implants completed the study at T2. The MBL was lower in the subcrestal group than in the crestal group (0.04 ± 0.08 vs. 0.17 ± 0.17 mm, p = 0.004). The peri-implant probing depth (PD) was 2.31 ± 0.48 mm in the subcrestal group and 1.92 ± 0.43 mm in the crestal group; this difference was statistically significant (p = 0.002). Intragroup comparison showed no significant differences in MBL, or PD around the crestal group and subcrestal group from T1 to T2.

CONCLUSION

After 1 year of functional loading, subcrestal placement of implants with platform-switching and internal conical connection showed lower MBL and was associated with greater PD and peri-implant soft tissue height than implants placed at the crestal level.

Accuracy of implant site preparation in robotic navigated dental implant surgery

BACKGROUND

Modern technological advancements have led to increase in the development of surgical robots in dentistry, resulting in excellent clinical treatment outcomes.

PURPOSE

This study aimed to determine the accuracy of automatic robotic implant site preparation for different implant sizes by correlating planned and posttreatment positions, and to compare the performance of robotic and human freehand drilling.

METHOD

Seventy-six drilling sites on partially edentulous models were used, with three different implant sizes (Ø = 3.5 × 10 mm, 4.0 × 10 mm, 5.0 × 10 mm). The robotic procedure was performed using software for calibration and step-by-step drilling processes. After robotic drilling, deviations in the implant position from the planned position were determined. The angulation, depth, and coronal and apical diameters on the sagittal plane of sockets created by human and robotic drilling were measured.

RESULTS

The deviation of the robotic system was 3.78° ± 1.97° (angulation), 0.58 ± 0.36 mm (entry point), and 0.99 ± 0.56 mm (apical point). Comparison of implant groups showed the largest deviation from the planned position for 5 mm implants. On the sagittal plane, there were no significant differences between robotic and human surgery except for the 5-mm implant angulation, indicating similar quality between human and robotic drilling. Based on standard implant measurements, robotic drilling exhibited comparable performance to freehand human drilling.

CONCLUSIONS

A robotic surgical system can provide the greatest accuracy and reliability regarding the preoperative plan for small implant diameters. In addition, the accuracy of robotic drilling for anterior implant surgery can also be comparable to that of human drilling.

Clinical outcomes of implant-supported prosthetic rehabilitation of severely atrophic maxilla: A systematic review

Aim

The purpose of this systematic review is to evaluate the clinical outcomes for the various methods of rehabilitation of a severely atrophic maxilla with the help of implant-supported fixed prosthesis.

Materials and Methods

The relevant publications published between 2013 and 2022 and written only in English were identified using an electronic search. The primary research question for this study was developed based on the PICO framework, which stands for population, intervention, control, and outcomes which was "What are the clinical outcomes of implant-supported prosthetic rehabilitation in patients with severely atrophic maxilla?" The relevancy of the articles was confirmed by examining their titles, abstracts, and complete texts to determine whether they satisfied the requirements for inclusion. Utilizing specialized study design-related bias assessment forms, the risk of bias was evaluated.

Results

The database search resulted in 1568 results; however, 1529 of them were eliminated because of insufficient, duplicate, or missing data. Additionally, manual searching yielded 11 articles. After 50 full-text papers were assessed for eligibility, 17 articles were eliminated. Thus, 33 studies in total are included in the current systematic review. Risk of bias analysis and GRADE evidence analysis were performed. Data were found to be heterogeneous and thus meta-analysis could not be done and narrative synthesis is presented.

Conclusion

The patient's condition and the clinician's expertise play a role in taking the decision on choice of technique for the fixed implant-supported rehabilitation of the severely atrophic maxilla. A high success and survival rate is produced by the majority of fixed implant-assisted prostheses despite the biologic and prosthetic problems. A single approach cannot be recommended as the gold standard. The choice is dependent on the patient's biological factors as well as the clinician's expertise. The included studies were assessed using GRADE criteria. The quality of evidence is low-medium. Therefore, to better comprehend the clinical effectiveness of the treatment alternatives, more well-designed randomized controlled trials with longer follow-up period are required.

Application of titanium 3D-printed double-sleeve guide for zygomatic implants: A technique report

The unique anatomical structure of the atrophic edentulous maxilla limits the placement of endosteal root form dental implants without bone grafting and augmentation. Surgical placement of zygomatic implants in an optimal position remains challenging. This technique report illustrates a novel digital guide technology, including the design workflow, application method, and indications for assisting with the placement of zygomatic implants using a bone-supported titanium double-sleeve guide. In addition, when the implant body reaches the zygomatic bone following an intra-sinus path, including ZAGA type 0 and ZAGA type 1 cases, a matching window osteotomy surgical guide is used to locate the lateral window boundary and protect the sinus membrane. With this technique, the surgical procedure is simplified, and the precision of guided zygomatic implant placement is improved.

Endoscope-assisted maxillary sinus floor augmentation with a mini-lateral window: A retrospective study

OBJECTIVES

The aim of this study was to evaluate the efficacy of endoscope-controlled sinus floor augmentation through a mini-lateral window, compared with traditional lateral window approach.

MATERIALS AND METHODS

This retrospective research included 19 patients and 20 augmented sinuses using lateral window approach with simultaneous implant placement (test group: a 3-4 mm round osteotomy; control group: a 10 × 8 mm rectangular osteotomy). Preoperatively (T0), immediately after surgery (T1), and 6 months postoperatively (T2), cone-beam computed tomography (CBCT) scans were obtained. Residual bone height (RBH), lateral window dimension (LWD), endo-sinus bone gain (ESBG), apical bone height (ABH), and bone density were measured. Intraoperative and postoperative complications were recorded. Patients' evaluation of pain first day after surgery and a week later was assessed by visual analog scale (VAS).

RESULTS

No significant difference was found in ESBG, ABH between the two groups at T1, T2 or their changes from T1 to T2. However, the increase of bone density value in the test group was significantly higher than control group (356.28 ± 149.59 vs. 242.99 ± 129.54; p < 0.05). The sinus perforation rate of test and control group was 10% and 20%, respectively. The VAS score of the test group at the first day after surgery was significantly lower than control group (4.20 ± 1.03 vs. 5.60 ± 1.71; p < 0.05).

CONCLUSIONS

Endoscope-controlled maxillary sinus floor augmentation through a mini-lateral window yield similar result with traditional approach in terms of bone height gain. The modified approach could facilitate new bone formation, reducing sinus perforation rate and postoperative pain.

Specific use of the implant stability quotient as a guide to improve healing for patients who had undergone rehabilitation with fixed implant-supported dental prostheses

PURPOSES

to develop a clinical approach to evaluating osteointegration around bone implants and try to determining which was the correct time of implant loading in different edentulous indications, that is, either properly positioned implants or implants "at risk", generally referred to as implants having increased probability of failure (namely those for which primary stability had been achieved via a time-consuming surgery).

MATERIALS

Several implant-supported rehabilitation strategies, with or without bone augmentation procedures, were performed in the upper and lower arches: From 2 to 5 months following implant placement, the prosthetic restorations were performed. A resonance frequency analyzer allowed clinicians to measure intraoperative and postoperative implant stability, then the values of the implant stability quotient, ISQ, ranging from 0 to 100, were registered. ISQs were ranked into 3 levels: Green (ISQ ≥ 70), Yellow (60 ≤ ISQ < 70), and Red (ISQ < 60). Groups were subjected to Pearson's χ2 analysis, with YATES correction when necessary, with a significance level of 0.05.

RESULTS

A total of 213 implants had been included. When the distribution of normalized values of ISQ registered for implants inserted in native bone and loaded at 2-3 months (5 Red, 19 Yellow, and 51 Green) was compared to that of native implants loaded after 4-5 months (4 Red, 20 Yellow, and 11 Green), a significative difference was found (p-value = 0.0037). At the time of loading, significance was lost. Significant clinical improvements on the distribution of normalized values of ISQ were apparent for both the implants placed in pristine and those placed in lifted sinuses; no significant differences were registered between the two groups.

CONCLUSION

At the loading time, implants considered to be at risk behaved similarly to the native sites for which the overall prosthetic workflow took about few; results confirmed that the mandibular implants appeared to have higher stabilities when compared to maxillary implants at both the intraoperative and the postoperative surveys.

Evaluating the influence of the mandibular canal trajectory on the duration of postoperative paraesthesia in patients undergoing inferior alveolar nerve lateralisation: a prospective cohort study

This prospective cohort study aims to evaluate the influence of the mandibular canal trajectory on the duration of postoperative paraesthesia in patients undergoing inferior alveolar nerve lateralisation (IANL). Twenty patients received a total of 50 dental implants, and their postoperative paraesthesia duration, implant success rate, and anatomical variables were assessed. All patients experienced temporary neurosensory disturbances postoperatively during the first week, but none reported permanent issues at the 12-month follow up. The median paraesthesia duration was 120 days, and no significant differences were detected between genders, anaesthesia types, or patient satisfaction. No significant association was found between the mandibular canal trajectory and postoperative paraesthesia duration. The implant success rate was 100%, with all implants integrating successfully. Our findings suggest that IANL is a safe and effective method for dental implant placement in atrophic mandibles.

Low Bone Density Predictability of CBCT and Its Relation to Primary Stability of Tapered Implant Design: A Pilot Study

Research regarding bone density assessment using cone beam computed tomography (CBCT) in low bone density regions is sparse. This in vitro study aimed to evaluate the predictability of CBCT for low bone density regions and its correlations with primary implant stability when placing tapered design implants with a stepped osteotomy. Eighteen porcine mandibular condyles were used as simulated low bone density regions. Hounsfield units (HU), obtained via multislice computed tomography, and gray values (GVs), obtained via CBCT, were measured 3 times at 1-month intervals. The maximum implant insertion torque (MIT) and implant stability quotient (ISQ) were recorded as the taper design implants were placed using a stepped osteotomy. Hounsfield units and GV were measured as 335.05-803.07 and 389.98-906.40, respectively. For repeated measurements of HU and GV, the intraclass correlation coefficients were 0.989 and 0.980; the corresponding value for mean HU and GV was 0.768. Bland-Altman plots showed a mean difference between HU and GV of -78.15. Pearson correlation coefficients revealed a strong correlation between HU and GV (r = 0.91, P < .01). The mean ± SD values for MIT and ISQ were 36.44 ± 6.64 Ncm and 80.85 ± 2.03, respectively, but no statistically significant correlations were found with GV and HU. Within the study's limitations, GV showed similar bone density estimation compared with HU in soft bones. Tapered implant placement with a stepped osteotomy achieved stable primary implant stability in soft bones. However, these in vitro results need to be approved in further clinical studies.

Lateral augmentation of the jaw by the split expansion ridge technique. A critical review

Bone augmentation has become a routine procedure to enhance and/or repair a deficient or resorbed alveolar ridge for predictable and successful implant placement. The split expansion ridge i.e., the alveolar ridge splitting (ARS) procedure, is one of the less invasive procedures, and is characterized by minor morbidity. This would allow to widen narrow ridges in order to allow implant reconstruction in a sufficient bone volume. Its efficacy and long-term stability rely upon clinical opinions and long-term retrospective studies, while prospective comparative studies and randomized controlled trials are rare. This critical review presents the development of this technique, describes the surgical procedure, and provides technical notes and modifications. The learning curve and in-depth knowledge of the oral anatomy, as well as the recognition of incidence and management of complications are of utmost importance in the clinical application of the ARS procedure.

Retrospective analysis of three different xenografts in maxillary sinus augmentation: histologic and three-dimensional radiologic study

OBJECTIVES

Low bone density and lack of adequate vertical bone dimension as a result of maxillary sinus pneumatization present some of the most problematic cases for endosseous implant applications in posterior maxillary regions that hinder prosthetic rehabilitation. The overall objectives of the study were to assess the histologic, histomorphometric, and radiologic evaluation of biopsies gathered from maxillary sinuses that were grafted with three different bovine bone particles (Bio-Oss, Cerabone, and Ti-Oss) and analyze the volume of the bone graft and the quantity of new bone formation.

METHOD AND MATERIALS

Thirty-six patients with < 4 mm of residual ridge height unilaterally in the posterior maxilla were equally divided into three groups, each of which received different bovine bone particles for maxillary sinus augmentation. Six months later, biopsies were harvested for histologic and histomorphometric evaluations. Volumetric changes in maxillary sinus augmentation were analyzed at 1-week and 6-month time-points following maxillary sinus augmentation surgery.

RESULTS

Histomorphometric and histologic analysis revealed a significant difference between the Ti-Oss group compared with the Bio-Oss and Cerabone groups (P = .011). In terms of residual graft particles and soft tissue, there were no significant differences between groups. 3D volumetric reductions between 1-week (baseline) and 6-month time-points recorded significant graft volume reduction in all groups (P < .05). Significantly greater bone resorption and lower new-bone formation were manifested in the Ti-Oss group in comparison to the other groups.

CONCLUSIONS

Within the limits of this study, histologic and radiologic results indicated that Bio-Oss and Cerabone could be used efficiently in sinus augmentation procedures, while further prospective studies are needed to evaluate the Ti-Oss material in maxillary sinus augmentation.

Radiographic analysis of critical anatomical structures for pterygoid implant placement in Chinese patients with a severely atrophied maxilla

The pterygoid implant is a feasible alternative for posterior dental rehabilitation without grafting; however, the ideal pterygoid implant placement continues to be debated. The aim of this study was to identify effective landmarks and establish valid guidelines to determine the ideal pterygoid implant placement. Cone beam computed tomography (CBCT) data of 100 severely atrophied maxillae requiring implant rehabilitation, obtained between January 2015 and December 2018, were included. The CBCT data were obtained in DICOM format from the radiographic database and imported into Nobel Clinician software (Nobel Biocare) for radiographic analysis. Virtual pterygoid implant placement was successful in 67 maxillae: a 13-mm virtual implant in four maxillae (6.0%), 15-mm in 52 maxillae (77.6%), and 18-mm in 11 maxillae (16.4%). For the virtual pterygoid implant, the mean implant angulation± standard deviation in the anteroposterior axis (sagittal view) was 45.08 ± 2.56° relative to the Frankfort plane. In the buccopalatal axis (coronal view), the mean implant angulation was 64.30 ± 4.99° relative to the Frankfort plane and the mean value for the shortest linear distance between the palatine canal and apical tip of the virtual implant was 3.91 ± 0.62 mm. A 15-mm pterygoid implant placed at 45° in the anteroposterior axis and 60° in the buccopalatal axis (relative to the Frankfort plane), is generally recommended in this Chinese patient population.

Partial Extraction Therapy (Part 2): Complication Management in Full-Arch Dental Implant Therapy

Partial extraction therapy (PET) is a group of surgical techniques that preserve the periodontium and peri-implant tissues during restorative and implant therapy by conserving a portion of the patient's own root structure to maintain the blood supply, derived from the periodontal ligament complex. PET includes the socket shield technique (SST), proximal shield technique (PrST), pontic shield technique (PtST), and root submergence technique (RST). Although their clinical success and benefits have been demonstrated, several studies report possible complications. The focus of this article is to highlight management strategies for the most common complications associated with PET, including internal root fragment exposure, external root fragment exposure, and root fragment mobility.

Treatment of Esthetic Complications with Peri-implant Soft Tissue: A Description of the "Apical Approach" Surgical Technique and Presentation of Two Clinical Cases

Peri-implant soft tissue deformities are an increasingly common phenomenon in the esthetic zone. While the most widely studied esthetic complications are peri-implant soft tissue dehiscences, there are other esthetic concerns in routine clinical practice that require investigation and treatment. Thus, this report on two clinical cases describes a surgical approach using the apical access technique to treat peri-implant soft tissue discoloration and fenestration. In both clinical scenarios, the defect was accessed via a single horizontal apical incision without removing the cement-retained crowns. A bilaminar technique using apical access with a simultaneous connective tissue graft seems to offer promising results for the treatment of peri-implant soft tissue deformities. At the 12-month reevaluation, an increase in peri-implant soft tissue thickness was observed, resolving the pathologies presented.

Volumetric analysis on the use of customized healing abutments with or without connective tissue graft at flapless maxillary immediate implant placement: A randomized clinical trial

OBJECTIVES

To evaluate buccal volume change after using a customized healing abutment with or without connective tissue grafts (CTG) in flapless maxillary immediate implant placement (IIP).

MATERIALS AND METHODS

The present study was designed as a randomized clinical trial (RCT). Patients treated with flapless maxillary IIP were allocated into two groups, both receiving a customized healing abutment, and additionally, the test group received a CTG. A cone-beam computerized tomography (CBCT) allowed to access the initial buccal bone thickness (BT). Digital impressions were taken prior to extractions (T0), 1 month (T1), 4 months (T2), and 12 months (T3) after implant insertion and superimposed with computer software allowing to compute variables related to buccal volume variation (BVv) and total volume variation (TVv) (ClinicalTrials.gov: NCT05060055).

RESULTS

Thirty-two patients (mean age 48 ± 11 years), sixteen in each group, were evaluated after a 12-month period. After 1 year of treatment, no significant differences were found between groups, although in participants with BT ≤1 mm, control and test groups showed a BVv of -14.18 ± 3.49% and -8.30 ± 3.78%, respectively (p = .033). Regarding mucosa height variation variables, the control group showed approximately the triple vertical recession in both papillae.

CONCLUSIONS

The placement of a CTG was not capable of completely maintaining the initial peri-implant tissue architecture, although in thin-bone phenotypes, less dimensional changes are expected when a CTG was used.

Pre-implant and implant management of oligodontia patients: A 10-year retrospective study

INTRODUCTION

the aim of this study was to report and assess the management and implant rehabilitation of oligodontia patients since its recognition in 2012 by french authorities in the nomenclature.

MATERIAL AND METHODS

we conducted a retrospective study in the Maxillofacial Surgery and Stomatology Department of the Lille University Hospital between January 2012 and May 2022. Patients had to present an oligodontia recognized under the ALD31 in adulthood, and to have benefited from a pre-implant/implant surgical treatment in the unit.

RESULTS

a total of 106 patients were included in the study. The mean number of agenesis was 12 per patient. The most missing teeth are the ones at the end of the series. After a pre-implant surgery phase including orthognathic surgery and/or bone grafting, 97 patients benefited from implant placements. The mean age for this phase was 19.38. A total of 688 implants were placed. The median number of implants placed was 6 per patient and 5 patients presented implant failures after or during the osseointegration phase (16 implants lost). The implant success rate was 97.6%. 78 patients benefited from rehabilitations by fixed implant-supported prostheses and 3 by implant-supported mandibular removable prostheses.

DISCUSSION

The described care pathway seems to us adapted to the patients followed in our department, with good functional and esthetic results. It would be necessary to evaluate on a national scale to adapt the management process.

The Curved Presplitting Technique in a Totally Edentulous Atrophic Mandible: A Surgical Case Report

The management of horizontally fully edentulous atrophic ridges is a common problem in dental implantology. This case report describes an alternative modified two-stage presplitting technique. The patient was referred for an implant-supported rehabilitation of their edentulous mandible. CBCT scans showed a mean available bone width of about 3 mm. At the first stage, four linear corticotomies were performed using a piezoelectric surgical device. At the second surgical stage 4 weeks later, bone expansion was performed, and four implants were placed in the interforaminal area. The healing process was uneventful. No fractures of the buccal wall and no neurologic lesions were observed. Postoperative CBCT scans showed a mean bone width gain of about 3.7 mm. Implants were uncovered 6 months after the second surgery, and 1 month later, a fixed provisional screw-retained prosthesis was delivered. This approach could be used as a reconstructive technique that avoids using grafts and reduces treatment times, possible complications, postsurgical morbidity, and costs by exploiting the patient's native bone as much as possible. Considering the limitations of a case report, randomized controlled clinical trials are needed to confirm the results and validate this technique.

Immediate Implant Placement in the Esthetic Zone Using a Novel Tapered Implant Design and a Digital Integrated Workflow: A Case Series

The purpose of this case series was to assess the application of a novel self-cutting, tapered implant (Straumann® BLX, Institut Straumann AG, Basel, Switzerland) in combination with a digital integrated prosthetic workflow for the immediate placement and restoration. Fourteen consecutive patients, requiring replacement of a single hopeless maxillary or mandibular tooth, meeting the clinical and radiographic indication criteria for immediate implant placement, were treated. All cases followed the same digitally-guided procedure of extraction and immediate implant placement. Immediate temporization with full contoured screw-retained provisionals was performed using an integrated digital workflow. After implant placement and dual-zone bone and soft tissue augmentation, connecting geometries and emergence profiles were finalized. The average implant insertion torque was 53.2 ± 14.9 Ncm and ranged between 35 and 80 Ncm, allowing immediate provisional restoration in all cases. Final restorations were delivered three months after implant placement. An implant survival rate of 100% was observed at the 1-year recall after loading. The results of this case series suggest that immediate placement of novel tapered implants and immediate provisionalization using an integrated digital workflow can result in predictable functional and esthetic results for the immediate transition of failing single teeth in the esthetic area.

Assessment of absorbable gelatin sponge for maxillary sinus floor elevation versus anorganic bovine bone minerals: a randomized clinical trial

PURPOSE

The present study compared the absorbable gelatin sponge as a space-filling material versus anorganic bone bovine mineral (ABBM) in maxillary sinus augmentation with simultaneous endosseous dental implant placement.

METHODS

Eighteen maxillary sinus floor elevation cases were randomly allocated into two groups. The first group received ABBM, while the second group received an absorbable gelatin sponge as a space-filling material. For both groups, CBCT scans were obtained immediately postoperatively and six months later to calculate the difference in sinus floor bone gain. Osstell readings were recorded both at the time of implant placement and implant exposure with a total of twenty-three dental implant placements in relation to the eighteen elevated sinus floors.

RESULTS

The mean radiographic sinus floor gain in the ABBM group was 10.2 mm (± 2.5), while in the absorbable gelatin sponge group was 5.4 mm (± 2.0), with a mean difference of 4.8, which was statistically significant (p < 0.001). The mean implant stability for the ABBM was 77.3 (± 4.9), while in the absorbable gelatin sponge group was 74.2 (± 3.0), with a mean difference of 3.1, which was statistically insignificant (p = 0.1610).

CONCLUSION

The ABBM showed superior results regarding the amount of radiographic sinus floor bone gain. However, the implant stability was invariable between both groups.

Bone Shell Technique with Relocated Crestal Ridge Segment for Anterior Horizontal Mandibular Ridge Atrophy: A Case Series

Horizontal and vertical ridge augmentation via the bone shell technique provides predictable outcomes. The external oblique ridge is the most-used donor site for bone plate harvesting, followed by the mandibular symphysis. The lateral sinus wall and the palate have also been described as alternative donor sites. This preliminary case series reports a bone shell technique that used the coronal segment of the knife-edge ridge as a bone shell in five consecutive edentulous patients (20 sites) with severe mandibular horizontal ridge atrophy and adequate ridge height. The follow-up period was 1 to 4 years. The average horizontal bone gains at 1 mm and 5 mm below the newly formed ridge crest were 3.6 ± 0.76 mm and 3.4 ± 0.92 mm, respectively. Ridge volume was sufficiently restored in all patients to enable implant placement in a staged approach. In 2 of the 20 sites, additional hard tissue grafts were required at implant placement. The advantages of utilizing the relocated crestal ridge segment are as follows: The donor and recipient sites are the same, no major anatomical structures are compromised, periosteal releasing incisions and flap advancement are not required for primary wound closure, and the risk of wound dehiscence is minimized due to reduced muscle tension.

Effect of Novel Low-intensity Pulsed Ultrasound Stimulation on Accelerated Implant Osteointegration in Canine

AIM

To evaluate the effect of low-intensity pulsed ultrasound (LIPU) application on dental implant accelerated osseointegration in the two-stage implant protocol.

MATERIALS AND METHODS

A total of 20 implants were placed in 10 mature mongrel dogs, two implants for each dog replacing the lower 3rd premolars bilaterally. After 3 months of extraction, implants were placed. After 24 hours of implantation, the right sides received LIPU for 20 mins/day, continuously for 20 days. The left sides didn't receive LIPU (control). Standardized radiographs were taken before LIPU and after 10 and 20 days for both sides. After 20 days of LIPU application, second-stage surgery was performed and provisional crowns were placed on each implant. Implants were subjected to functional occlusal loading for 4 weeks. Standardized radiographs were taken after 2 and 4 weeks of loading and analyzed to assess the peri-implant bone density changes. All data were collected, tabulated, and statistically analyzed.

RESULTS

All tissues appeared clinically normal, with the absence of inflammation and peri-implant radiolucency. The survival rate was 100%. The LIPU group showed a statistically significantly higher percentage increase in mean bone density after 10 LIPU sessions, 20 LIPU sessions, and 2 and 4 weeks of loading, than a control group.

CONCLUSION

The LIPU stimulation radiographically increased the bone density around implant area and accelerated osseointegration in the two-stage implant protocol.

CLINICAL SIGNIFICANCE

Low-intensity pulsed ultrasound stimulation could be beneficial in accelerating osseointegration and thus shortening the waiting period for final prosthetic delivery.

Changes in bone graft height and influencing factors after sinus floor augmentation by using the lateral window approach: A clinical retrospective study of 1 to 2 years

STATEMENT OF PROBLEM

Recent systematic reviews have reported resorption of bone grafts after augmentation, but the influencing factors are numerous and uncertain. Different brands of bone graft and other factors may affect the bone formation effect after sinus floor augmentation.

PURPOSE

The purpose of this retrospective clinical study was to evaluate the graft material height changes after sinus floor augmentation with cone beam computed tomography (CBCT) and to investigate the potential influencing factors related to graft resorption.

MATERIAL AND METHODS

Four midsagittal cut CBCT images of 157 posterior maxillary implants after maxillary sinus floor elevation by using the lateral window approach with bone grafts from 116 patients were obtained. Four CBCT scans had been performed immediately (T0), 6 months (T1) and 12 months after bone grafting (T2), and 1.5 to 2 years after treatment (T3), and the distance between the implant platform and the grafted mucosa of the maxillary sinus floor was measured at 3 locations. Correlation coefficients of these parameters were calculated. A linear mixed model was used to investigate potential factors influencing graft height reduction, including the patient's sex, age, smoking status, periodontal status, graft brand, implant site, implant level, placement time, and residual bone height.

RESULTS

Mean ±standard deviation graft height at the mesial side of the implant (MeGH) was significantly decreased by 0.32 ±0.88 mm in the first 6 months, was gradually reduced after 6 months (0.26 ±0.43 mm), and then 1 to 2 years later increased to 0.39 ±0.97 mm. The changes in graft height at the center of the implant (CeGH) and graft height at the distal side (DiGH) groups were similar to those in the MeGH group. A significantly positive correlation was found among the height alterations in 3 locations (rs=0.954, P<.001). The linear mixed model showed that smoking was more likely to cause graft height reduction in MeGH (P=.034).

CONCLUSIONS

Graft height significantly decreased after maxillary sinus augmentation over 1 to 2 years. Smoking had a negative effect on graft height changes, while the 2 brands of graft and other factors had no significant effect.