International journal of oral implantology (Berlin, Germany)最新文献

Purpose: Accurate extraction socket evaluation is crucial for aesthetic success with immediate implant placement. The present authors propose a socket classification system to assist selection of the approach most likely to offer an optimal aesthetic outcome. The objectives of this study were to describe this novel system and evaluate the inter-rater agreement.

Materials and methods: Socket type identification was based on three parameters: the position of the gingival margin in relation to the homologous tooth, the morphology of the buccal bone plate, and the interproximal attachment level (the latter two were evaluated through gingival probing). These data were used to identify four socket types, including three from a widely applied classification system, which were subdivided into two subtypes to give types 1A, 1B, 2A, 2B, 3A, 3B, 4A and 4B. After establishing a 'gold standard' classification, a questionnaire was sent to 50 postgraduate students and 45 experienced dental practitioners.

Results: A simple system was used to classify single extraction sockets from observations of marginal and interproximal tissues. In a sample of 95 examiners, the percentage agreement with gold standard classifications was 78.7% ± 0.023% [0.56% to 0.98%] and was not significantly influenced by the examiner's level of clinical experience (P > 0.05). Treatment recommendations were proposed for each socket type.

Conclusion: The single extraction socket classification for aesthetic outcomes simplifies the prediction of aesthetic outcomes and provides a rational basis for the approach to each socket type.

An advantage of treated implant surfaces is their increased degree of hydrophilicity and wettability compared with untreated, machined, smooth surfaces that are hydrophobic. The present preclinical in vivo study aimed to compare the two implant surface types, namely SLActive (Straumann, Basel, Switzerland) and nanohydroxyapatite (Hiossen, Englewood Cliffs, NJ, USA), in achieving early osseointegration. The authors hypothesised that the nanohydroxyapatite surface is comparable to SLActive for early bone-implant contact. Six male mixed foxhounds underwent mandibular premolar and first molar extraction, and the sockets healed for 42 days. The mandibles were randomised to receive implants with either SLActive (control group) or nanohydroxyapatite surfaces (test group). A total of 36 implants were placed in 6 animals, and they were sacrificed at 2 weeks (2 animals), 4 weeks (2 animals) and 6 weeks (2 animals) after implant surgery. When radiographic analysis was performed, the difference in bone level between the two groups was statistically significant at 4 weeks (P = 0.024) and 6 weeks (P = 0.008), indicating that the crestal bone level was better maintained for the test group versus the control group. The bone-implant contact was also higher for the test group at 2 (P = 0.012) and 4 weeks (P = 0.011), indicating early osseointegration. In conclusion, this study underscored the potential of implants with nanohydroxyapatite surfaces to achieve early osseointegration.

Dental implants are a reliable treatment option for restoring missing teeth, but adequate bone quantity and quality are crucial for success. This case series presents four cases treated by different clinicians, all following very similar concepts for combined periodontal and vertical ridge augmentation using recombinant human platelet-derived growth factor-BB. All cases involved a severe periodontal defect requiring either extraction of the adjacent tooth or periodontal regeneration. Different bone grafts and membrane types were utilised. Although true periodontal regeneration cannot be said categorically to have occurred due to a lack of histological evidence, the clinical and radiographic findings suggest almost complete bone fill in all cases. This case series demonstrates that combined periodontal and vertical ridge augmentation using recombinant human platelet-derived growth factor-BB could be successful, but proper case selection and patient preparation for the possibility of multiple surgical procedures are recommended. Conflict-of-interest statement: At the time of preparing this manuscript, Dr Saleh was a clinical advisor for Lynch Biologics, Franklin, TN, USA. The other authors declare that they have no conflicts of interest relating to this study.

Purpose: To compare the clinical effectiveness of three different devices used in guided bone regeneration procedures for partially atrophic arches.

Materials and methods: A randomised controlled trial with three parallel arms was conducted. The study evaluated titanium-reinforced polytetrafluoroethylene membrane (PTFE group), semi-occlusive CAD/CAM titanium mesh (mesh group) and occlusive CAD/CAM titanium foil (foil group) in terms of surgical outcomes and complications as well as surgical times and surgeon satisfaction in 27 guided bone regeneration procedures, presenting results from 1 year post-implant placement.

Results: Complications occurred in seven patients. No significant difference was found between the groups in terms of the occurrence of complications (P = 0.51), device exposure (P = 0.12) and implant failure (P = 0.650). Surgeon satisfaction varied significantly, with the PTFE group differing from the mesh (P = 0.003) and foil groups (P 0.001), but not between meshes and foils (P = 0.172). Surgical times also differed significantly, with longer times for PTFE membranes compared to meshes (P 0.001) and foils (P = 0.006), but with no difference between meshes and foils (P = 0.308). The mean reconstructed bone volume was 1269.55 ± 561.08 mm3, with no significant difference observed between the three groups (P = 0.815). There was also no significant difference for mean maximum height (6.72 mm, P = 0.867) and width (7.69 mm, P = 0.998). The mean marginal bone loss at 1 year after implant placement was 0.59 ± 0.27 mm.

Conclusions: Although this study provides valuable insights into the potential benefits of using different types of CAD/CAM devices, further research with larger sample sizes and longer follow-up periods is warranted to validate these findings.

Conflict-of-interest statement: The authors declare there are no conflicts of interest relating to this study.

The following amendments are made to the published article: Int J Oral Implantol (Berl) 2024;17(1):105-117; First published 19 March 2024.

Purpose: Complex bone defects with a horizontal and vertical combined deficiency pose a clinical challenge in implant dentistry. This study reports the case of a young female patient who presented with a perforating bone defect in the aesthetic zone.

Materials and methods: Based on prosthetically guided bone regeneration, virtual 3D bone augmentation was planned. A 3D printed customised titanium mesh and the autogenous bone ring technique were then utilised simultaneously to achieve a customised bone contour. After 6 months, the titanium mesh was removed and connective tissue grafting was performed. Finally, implants were placed and the provisional and definitive prostheses were delivered following a digital approach. Vertical and horizontal bone gain, new bone density, pseudo-periosteum type and marginal bone loss were measured. Planned bone volume, regenerated bone volume and regeneration rate were analysed.

Results: Staged tooth shortening led to a coronal increase in keratinised mucosa. The customised titanium mesh and bone ring technique yielded 14.27 mm vertical bone gain and 12.9 mm horizontal bone gain in the perforating area. When the titanium mesh was removed, the reopening surgery showed a Type 1 pseudo-periosteum (none or < 1 mm), and CBCT scans revealed a new bone density of ~550 HU. With a planned bone volume of 1063.55 mm3, the regenerated bone volume was 969.29 mm3, indicating a regeneration rate of 91.14%. The 1-year follow-up after definitive restoration revealed no complications except for 0.55 to 0.60 mm marginal bone loss.

Conclusion: Combined application of customised titanium mesh and an autogenous bone ring block shows promising potential to achieve prosthetically guided bone regeneration for complex bone defects in the aesthetic zone.

Purpose: The reverse guided bone regeneration protocol is a digital workflow that has been introduced to reduce the complexity of guided bone regeneration and promote prosthetically guided bone reconstruction with a view to achieving optimal implant placement and prosthetic finalisation. The aim of the present study was to investigate the accuracy of this digital protocol.

Materials and methods: Sixteen patients with partial edentulism in the maxilla or mandible and with vertical or horizontal bone defects were treated using the reverse guided bone regeneration protocol to achieve fixed implant rehabilitations. For each patient, a digital wax-up of the future rehabilitation was created and implant planning was carried out, then the necessary bone reconstruction was simulated virtually and the CAD/CAM titanium mesh was designed and used to perform guided bone regeneration. The computed tomography datasets from before and after guided bone regeneration were converted into 3D models and aligned digitally. The actual position of the mesh was compared to the virtual position to assess the accuracy of the digital project. Surgical and healing complications were also recorded. A descriptive analysis was conducted and a one-sample t test and Wilcoxon test were utilised to assess the statistical significance of the accuracy. The level of significance was set at 0.05.

Results: A total of 16 patients with 16 treated sites were enrolled. Comparing the virtually planned mesh position with the actual position, an overall mean discrepancy between the two of 0.487 ± 0.218 mm was achieved. No statistically significant difference was observed when comparing this to a predefined minimum tolerance (P = 0.06). No surgical complications occurred, but two healing complications were recorded (12.5%).

Conclusion: Within the limitations of the present study, the reverse guided bone regeneration digital protocol seems to be able to achieve good accuracy in reproducing the content of the virtual plan. Nevertheless, further clinical comparative studies are required to confirm these results.

Maxillary sinus grafting is a predictable regenerative technique to facilitate maxillary posterior implant placement when there is insufficient vertical bone height inferior to the maxillary sinuses to allow placement of implants of adequate dimensions. It enables an increase in vertical bone height, which makes implant placement easier. Maxillary sinus mucosal membrane perforation is one of the most common intraoperative complications during maxillary sinus grafting and may result in extrusion of graft material into the sinus. When this occurs, the mucociliary function of the maxillary sinus may expel the extruded graft material through its natural ostium, though graft particles may remain in the sinus or possibly occlude the natural ostium. After grafting, transient maxillary sinus mucosal oedema may occur. A postoperative CBCT scan may reveal varying degrees of sinus opacification, namely partial, subtotal or total. Although it is always possible to identify graft material, which may enter the sinus as a result of membrane perforation that might not even be visible to the implantologist during the surgical procedure, it is challenging to assess whether sinus opacification is due to mucosal thickening or mucus accumulation. The aim of the present case series was to offer a pragmatic approach to managing asymptomatic patients whose CBCT scans demonstrated partial, subtotal or total maxillary sinus opacification with bone graft particles that seemed to have been extruded into the sinus.

Purpose: To examine the effects of buccal bone fenestration on maxillary anterior implants.

Materials and methods: Patients who underwent implant placement in the maxillary anterior region between January 2017 and December 2021 and had received final restorations 1 to 6 years prior were screened for inclusion in the present study. Propensity score matching was used to match the two-group sample size and reduce the influence of potential confounding factors. Generalised linear mixed models were employed to evaluate the correlation between buccal bone fenestration and peri-implant marginal bone loss.

Results: A total of 42 patients with 50 implants were included in the study, 16 of whom had buccal bone fenestration (group 1) and 26 of whom did not (group 2). No implant failures occurred, resulting in a cumulative implant survival rate of 100.0%. There was no statistically significant difference between the pink aesthetic scores for the two groups. The mean marginal bone loss was 0.44 ± 0.46 mm for group 1 and 0.33 ± 0.32 mm for group 2 (P > 0.05). Buccal bone fenestration was not the influencing factor of marginal bone loss (P > 0.05). Marginal bone loss was greater around implants used to replace canines than those inserted to replace central incisors (P < 0.05). Far less marginal bone loss occurred around immediately loaded implants than delayed implants with cover screws (P < 0.05). When there is sufficient keratinised mucosa around the implant, marginal bone loss will decrease significantly (P < 0.05).

Conclusions: Within the limitations of this study, buccal bone fenestration defects around dental implants cannot influence peri-implant bone loss.

Conflict-of-interest statement: The authors report no conflicts of interest relating to this study.