Clinical implant dentistry and related research最新文献

Maxillary sinus floor elevation is usually performed in two different ways: the lateral approach involves the creation of a bony window on the maxillary sinus lateral wall, providing direct access to the sinus cavity for membrane elevation and subsequent graft placement, and the transcrestal approach is considered less invasive. The aim of this article is to describe, based on the literature, how to anticipate, avoid, and manage the intraoperative complications that can occur with both approaches. For both approaches, the most common complication is the sinus membrane perforation. For the lateral approach, an average frequency ranging from 15.7% to 23.1% is reported, but because of the better visibility, their management will be easier compared to the transcrestal approach. Mean perforation rate reported for the transcrestal approach is lower (3.1%-6.4%), but it should be noted that a significant number of perforations cannot be detected and managed given the blind nature of this technique. Anatomical parameters such as sinus width and buccal wall thickness may be a risk factor for one approach and not the other. As it is impossible to assess the resistance of the Schneiderian membrane, the transcrestal approach is more likely to lead to infectious complications in the event of perforation. Others, such as the risk of vascular damage, are encountered only with the lateral approach, which can be prevented easily by dissecting the alveolo-antral artery. For both approaches, prevention is essential and consists in analyzing the anatomy, mastering the surgical technique, and collaborating with the ENT to manage the essentially infectious consequences of intraoperative complications.

Objectives: This study evaluates the clinical performance of implants with hydrophilic surface and two different macrostructures: cylindrical with perforating triangular threads (CT) and cylindrical-tapered with the association of square and condensing and perforating triangular threads (TST).

Materials and methods: This was a multicenter split-mouth, simple-blinded, randomized, and controlled trial. Thirty patients with edentulous mandible received two CT and two TST implants. Primary stability was determined by insertion torque and resonance frequency analysis (RFA). Implants were loaded with full fixed-arch prostheses within 24 h after insertion. Clinical parameters (visible plaque index, marginal bleeding index; bleeding on probing; probing depth; and clinical attachment level) and the RFA were assessed at 2, 6, 12, and 24 months after implant loading. Marginal bone level changes were measured by comparison of standardized radiographs taken on the day of implant placement and 6, 12, and 24 months thereafter.

Results: Twenty-eight patients completed the 2-year follow-up. The survival rates were 99.16% for CT implants and 100% for TST implants. One CT implant was lost until the 2 months follow-up. No significant differences were found between the two implant types for marginal bone level changes (CT 0.34 [0.24; 0.55 mm]; 0.33 [0.18; 0.55 mm]; 0.41 [0.12; 0.7 mm] vs TST 0.36 [0.14; 0.74 mm]; 0.33 [0.23; 0.63 mm]; 0.30 [0.20; 0.64 mm] at 6, 12, and 24 months, respectively) and other clinical parameters.

Conclusion: The macrostructure of the implants had no influence on survival rate, primary and secondary stability, marginal bone level changes, and peri-implant clinical parameters outcomes. Both implants can be predictably used for immediate loading of full-arch mandibular prostheses.

Objective: To evaluate the feasibility of ultrasound-image-based computer-assisted implant planning and placement.

Materials and methods: Intraoral scans, cone-beam computerized tomography (CBCT), and ultrasound (US) scans with a custom positioning device were acquired in nine patients. Prosthetic-driven surgical guides were planned and fabricated based on ultrasound images and intraoral scans. Implants were then placed. Postoperative implant position was obtained intra-surgically by intraoral scan. Aside from the ultrasound-based plan, conventional implant planning was performed by the same operator on a pre-surgical CBCT for comparison. Linear deviations between ultrasound and CBCT-planned implant positions were measured and compared with the intra-surgical implant position, and the position deviations between two consecutive plannings were performed on the same CBCT by the same operator. The linear deviation between the 3D scan surface of the edentulous region and the ultrasonographic soft tissue profile segmentation was also assessed with reverse-engineering software. Means, standard deviations, and root mean square differences (RMSD) were calculated for every variable.

Results: All the ultrasound-planned implants were successfully placed, and no complications were recorded. The mean deviations in angles, shoulders, and apexes were 5.27 ± 1.75° (RMSD: 5.53°), 0.92 ± 0.26 mm (RMSD: 0.95 mm), and 1.41 ± 0.61 mm (RMSD: 1.53 mm), respectively, between the US and CBCT-planned implants; 2.63 ± 0.43° (RMSD: 2.66°), 1.16 ± 0.30 mm (RMSD: 1.19 mm), and 1.26 ± 0.27 mm (RMSD: 1.28 mm) between the planned implant and intra-surgically recorded positions; and 2.90 ± 1.36° (RMSD: 3.18°), 0.65 ± 0.27 mm (RMSD: 0.70 mm), and 0.99 ± 0.37 mm (RMSD: 1.05 mm) between two consecutive CBCTs planning performed by the same operator. The mean deviation between the 3D surfaces of model scans and ultrasound-derived soft tissue profile in the edentulous area was 0.19 ± 0.08 mm.

Conclusions: Ultrasound-guided implant surgery represents a feasible non-ionizing alternative to conventional static guided implant surgical protocols for implant placement in sites with favorable characteristics.

Osseodensification is a novel approach that has significantly advanced the field of implant dentistry, particularly in the context of transcrestal maxillary sinus floor elevation. This technique involves the use of specially designed burs that compact and densify bone along the osteotomy walls, thereby enhancing implant primary stability and facilitating osseointegration in low-density bone. This article reviews the historical evolution of implant site preparation, and the biomechanical, histological, and clinical evidence of osseodensification with a special focus on its application in sinus floor augmentation. The integration of this technique into contemporary practice represents a paradigm shift, offering a minimally invasive and efficient solution for addressing the challenges of posterior maxilla, with improved patient-reported outcomes and low complication rate. Three different protocols for sinus lift and implant placement using osseodensification burs are proposed based on available literature, and risk factors for Schneiderian membrane perforation based on residual bone height are discussed, along with implant-related outcomes and patient-reported outcome measures. The potential for osseodensification to become a standard practice in sinus floor augmentation is emphasized, highlighting key aspects such as surgical protocol and patient selection.

Objectives: This study aimed to report the clinical and radiographic results of 2.8 mm two-piece narrow diameter implant (NDI) supporting fixed restorations.

Materials and methods: Clinical and radiographic data of 54 NDIs in 32 patients were retrospectively assessed after 2 to 11 (mean 8.17) years of follow-up. Clinical and radiographic measurements were taken. Survival rate, implant and prosthesis failure, pink aesthetic scores (PES), white aesthetic scores (WES), bleeding on probing (BOP), probing depth (PD), marginal bone loss (MBL), and mechanical and biological complications were evaluated.

Results: An implant failed during the follow-up period, resulting in a cumulative survival rate of 98.15% at the implant level and 96.88% in the patient. The total mean values of PES and WES for 2.8 mm NDIs were 7.09 ± 1.15 (range: 3.33-9.00) and 7.42 ± 1.03 (range: 3.67-9.33). The prevalence of sites with positive BOP was 38.14 ± 29.77%. The mean PD value was 2.46 ± 0.62 mm. The average MBL was 1.15 ± 0.74 mm (range: 0.25-4.03 mm). No implant or abutment fracture was detected. A veneer chipping was present in one patient, and a loose crown appeared in another patient. Two implants (3.7%) and two patients (6.3%) were diagnosed with peri-implantitis.

Conclusion: Within the limitation of the study, the results indicate that the use of two-piece 2.8 mm NDI for the fixed prosthetic rehabilitation of edentulous regions with reduced interdental and/or buccal-lingual width is viable.

Introduction: Implant-supported removable complete overdentures (IODs) are a common treatment in case of edentulism and malfunctioning of the conventional denture. Manufacturing IODs in a conventional way (C-IODs) is time-consuming, but in a digital workflow, this can be done in three sessions. Digitally produced IODs (3D-IODs) are also more advantageous than C-IODs because lost or broken 3D-IODs can be swiftly reproduced as the digital design is always available.

Purpose: To prove in a non-inferiority study, with a margin of 0.3 point per Oral Health Impact Profile-20 (OHIP-20) question, that IODs made according to a fully digital workflow (3D-IODs), function as good as C-IODs with respect to patient-reported outcome measures (PROMs).

Materials and methods: This randomized crossover study included 36 fully edentulous patients who showed extreme resorption of the maxillary alveolar process, making denture retention difficult. After a maxillary bone augmentation and the installation of 4-6 implants, each patient wore both types of IOD for 1 year each, with the order reversed in two subsets of patients. The 3D-IODs and C-IODs were fabricated in advance for both jaws (at least two mandibular implants were already present). The OHIP-20 survey was performed at baseline, after 1 year (before the IOD switch), and after 2 years to determine patient satisfaction scores using a visual analog scale (VAS). The general health status was assessed using the Short Form (SF-36) questionnaire.

Results: Regarding the PROMs, patients preferred the 3D-IOD: the improvement on the overall OHIP scale (0-4), expressed as a mean, was 0.26 points greater than for the C-IOD (p < 0.001). This applied also to the VAS scale (1-100) with an increase of 7.37 points (p < 0.001). Regarding the SF-36 scale, only for the item "emotional well-being," the 3D-IOD scored significantly better (p = 0.033).

Conclusion: Compared with conventionally fabricated C-IODs, fully digitally produced 3D-IODs resulted in significantly higher OHIP-20 and satisfaction scores.

Introduction: Maxillary sinus floor elevation is a surgical procedure intended to increase the volume of the bone vertically to accommodate dental implant placement. This intervention is frequently required for implant installation in the posterior maxilla, where the bone may be insufficient for securing implants of necessary length and stability. Sinus floor elevation can be completed either through a direct approach with a "window" through the lateral wall of the alveolar ridge or an indirect "transcrestal/transalveolar" sinus floor elevation (TSFE), which accesses the sinus floor through the crest of the edentulous ridge. Our study aims to provide a comprehensive scoping review of research conducted over the past 25 years on TSFE, specifically.

Methods: A literature search aimed at identifying pertinent literature for the purpose of this PRISMA-ScR-compliant scoping review was conducted. Only randomized controlled trials, non-randomized controlled trials, prospective cohort studies, and case series that met the eligibility criteria were selected. Relevant data from these studies were extracted. Primary outcome measures included radiographic bone levels and implant failure >5 years. Secondary outcome measures included implant stability at time of placement and complications. Interventions reported in the selected studies were grouped based on treatment modality, which were then compared with the control therapy (traditional osteotome technique) after a minimum of 12 months healing period.

Results: Our search yielded 633 records, and after deduplication, 574 of these were screened. Application of the eligibility criteria led to the inclusion of 37 articles in the final selection. Case selection for included studies enrolling subjects: Four different transcrestal sinus elevation treatment modalities were identified: (a) osteotome, (b) piezoelectric surgery, (c) osseodensification, and (d) hydraulic techniques. Due to the heterogeneity of the studies, no superior approach for TSFE could be identified. Overall, all techniques demonstrated high implant survival rates.

Conclusion: Comprehensive understanding of the patient's medical history, available armamentarium, and post-operative complications/management strategies are all essential to the completion of a successful TSFE approach for implant placement in the posterior maxilla, regardless of the treatment modality used.

Objectives: This study aimed to evaluate the impact of different collagen membran fixation protocols on the volume stability in horizontal ridge augmentation in the aesthetic area.

Methods: A total of 48 patients with 65 augmented sites were included in this study. Implants were placed in the aesthetic region, and simultaneous guided bone regeneration (GBR) surgery was performed for horizontal ridge augmentation. Participants were divided into four groups, each comprising 12 patients, based on different absorbable collagen membrane fixation protocols. Group 1: without fixation; Group 2: fixation with absorbable sutures; Group 3: fixation with titanium pins; Group 4: fixation with titanium pins and absorbable sutures. Cone beam computed tomography (CBCT) was performed immediately after surgery and at 6 months post-surgery, respectively. The horizontal thickness of the augmented region was analyzed for volume stability at the implant shoulder (H0) and 1-5 mm apical to the implant shoulder (H1-H5). Changes in labial thickness during bone healing were calculated as absolute values (mm) and relative values (%).

Results: After 6 months of bone healing, horizontal thickness was significantly reduced at all levels (H0-H5) in all groups compared to immediate post-surgery results (p < 0.05). At H1-H5, horizontal bone loss in group 1 was significantly higher than in the other three groups (p < 0.05). Group 4 exhibited significantly less horizontal bone loss compared to group 2 at H0-H2 (p < 0.05) and group 4 compared to group 3 at H0-H1 (p < 0.05). No significant difference in horizontal bone loss between groups 2 and 3 was detected at H0-H5 (p > 0.05).

Conclusion: Guided bone regeneration in the aesthetic area with additional membrane fixation demonstrated superior volume stability of the augmented region compared to cases without fixation. There was no significant difference in bone volume stability between membrane fixation with titanium pins and fixation with absorbable sutures. However, the combined use of pins and absorbable sutures yielded superior volume stability.

Introduction: In cases of atrophy in the maxillary posterior region, characterized by reduced vertical bone volume, implant placement becomes challenging. Augmentation procedures like sinus lifts are often needed to address insufficient bone volume. This study aims to explore if alveolar ridge preservation, using a bovine bone substitute and a porcine collagen membrane, significantly decreases the need for sinus lifts compared to natural wound healing after tooth extraction.

Materials and methods: In this comparative clinical study, 40 patients requiring a total of 53 extractions were assigned to one of the following groups: a test group with bovine bone substitute material (Straumann® XenoFlex) and a porcine collagen membrane (Jason® membrane), or a control group with spontaneous socket healing. After 6 months, digital volume tomography was performed for implant planning.

Results: For seven patients from the control group (n = 22 extracted sites) sinus lift augmentations were performed while only four sinus lift procedures were performed in the test group (n = 31 extracted sites), indicating a higher need for sinus augmentation procedures in the control group, however not statistically different on a p value of 0.05 (p = 0.168). In the control group, the mean value of the radiographically measured bone height (mesial and distal) was 11.13 ± 2.12 mm preoperatively before tooth extraction, while it was 11.3 ± 2.17 mm postoperatively after implant placement. In contrast, the mean value in the test group was 11.78 ± 3.09 mm preoperatively and 11.92 ± 2.79 mm postoperatively. Statistical analysis revealed no significant difference between the two groups (odds ratio 0.32; 95% CI: 0.08, 1.26; p = 0.951). The implant survival rate in the control group was 100%, compared to 96.77% in the test group.

Conclusion: Within the limits of this study, the use of bovine bone substitute and a porcine resorbable membrane after tooth extraction in the posterior maxilla seems to reduce the need for sinus augmentation in comparison to spontaneous healing although the difference was not statistically significant. Additionally, the Alveolar Ridge Preservation in the test group made external sinus floor elevation unnecessary compared to the control group. The change in radiographically measured bone height pre- and postoperatively showed no significant difference between the two groups.

Purpose: To evaluate the mid-term clinical and radiographic results of immediate fixed full-arch prosthesis supported by two anterior axial and two posterior trans-crestally placed tilted implants in patients with severely atrophic posterior maxilla.

Materials and methods: Patients with posterior maxillary ridge less than 4 mm high and 3 mm wide were rehabilitated with an immediate fixed provisional prosthesis supported by two anterior axially placed and two trans-crestal posterior tilted implants within 3 h after implant surgery. The final prosthesis, consisting of a CAD-CAM titanium framework and composite teeth was delivered 6 months later. Patients were scheduled for follow-up visits every 6 months to assess clinical and radiological parameters. Patients' satisfaction was assessed by a questionnaire up to 5 years.

Results: From April 2008 to May 2017, 56 implants (28 axial and 28 tilted) were inserted in 14 subjects (eight female and six male). The average bone loss for the anterior axial implants was 0.99 ± 0.19 mm at 1 year (n = 28 implants), 1.37 ± 0.31 mm at 5 years (n = 28), and 2.05 ± 0.32 mm at 10 years (n = 14). Only for three implants in two subjects the marginal bone loss was higher than 2 mm after 60 months. No implant was lost, and no prosthetic failure occurred after a mean follow-up of 125 months (range 79-186 months), leading to 100% implant and prosthesis survival rates. The upper 95% confidence limit of the failure rate was 23% and 6% at patient and implant level, respectively. High level of satisfaction was reported at 5-year follow-up.

Conclusion: Wider sample sizes will be required to determine whether the presented technique is a reliable treatment option for the immediate rehabilitation of the atrophic maxilla.