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

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.

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.

Purpose: To provide an overview of the outcomes of the use of autogenous platelet concentrates in immediate implant placement.

Materials and methods: Based on an a priori protocol, a systematic search was performed of the National Library of Medicine (MEDLINE via PubMed), Embase and Scopus databases. Randomised and non-randomised controlled clinical trials on immediate implant placement including at least one study arm with use of platelet-rich fibrin or platelet-rich plasma as a gap filler between immediately placed implants and the alveolar bone were included. A random-effects meta-analysis model was built to assess the primary outcomes of marginal bone loss and probing pocket depths between test (platelet concentrates) and control (no graft or other graft materials) groups. A risk of bias assessment was performed and the Grading of Recommendations Assessment, Development and Evaluation approach was used to assess the certainty of evidence.

Results: A total of 20 trials (595 immediate implants placed in 454 individuals) were included in the meta-analytic model. Based on the data from studies with a minimum post-prosthetic loading period of 6 months after immediate implant placement, overall, the application of platelet concentrates was associated with significantly lower marginal bone loss and probing pocket depth compared to the control groups (mean difference -0.36 mm; P < 0.01 and mean difference -0.47 mm; P < 0.01, respectively). No additional benefit of application of platelet concentrates was detected regarding primary stability of immediate implants. Subgroup analysis revealed significantly lower marginal bone loss with xenogeneic bone alone compared to platelet concentrates alone as grafting material in immediate implant placement (mean difference 0.66 mm; P < 0.01). Evidence on soft tissue outcomes and aesthetic parameters was scarce.

Conclusions: A low level of certainty based on the Grading of Recommendations Assessment, Development and Evaluation approach indicates superior outcomes in terms of marginal bone loss and probing pocket depth in immediate implant placement with the use of platelet concentrates versus no graft. Future research should be tailored towards a standardised protocol for preparation of platelet concentrates and inclusion of soft tissue and aesthetic outcomes as well.

Purpose: To evaluate the survival and success rate of and the incidence of complications affecting implants inserted and immediately loaded in sites where an impacted tooth was present in the maxilla.

Materials and methods: A total of 10 patients were treated and 14 implants were inserted, 4 in healed sites and 10 in extraction sites. The implant site preparation started in the crestal bone and continued in the enamel and dentine of the impacted tooth. The radiographic depth of implant penetration into the impacted tooth, peri-implant soft tissue and hard tissue condition at the 1-year follow-up and the last follow-up appointment, marginal bone loss at the 1-year follow-up and the last follow-up appointment, and the final aesthetic result were evaluated.

Results: The implants healed uneventfully with an adequate hard and soft tissue response and no adverse clinical or radiographic signs or symptoms. They were in function for a minimum of 3 and a maximum of 11 years (mean 7.2 years).

Conclusion: Although further studies with a larger sample size are required to validate this unconventional approach, it can be considered a valuable clinical option to replace teeth in an area of impaction.

Purpose: To assess the implant failure rate and clinical and radiographic outcomes of implants affected by peri-implantitis that received surgical treatment.

Materials and methods: A systematic search was conducted of three databases (PubMed, Embase and Cochrane Library) to identify studies that examined implant failure and biological outcomes after surgical peri-implantitis treatment, including ≥ 10 patients and reporting on a follow-up period of at least 12 months. Data and risk of bias were assessed qualitatively and quantitively. Surgical modalities were subdivided into reconstructive, non-reconstructive and combined. Meta-analyses were performed for implant failure, marginal bone level and probing pocket depth at 12 and 36 months with the respective subset of available data for each time and endpoint.

Results: A total of 45 studies with 3,463 treated implants were included in the quantitative evaluation. Meta-analyses revealed low implant failure rates of 1.2% (95% confidence interval 0.4%, -2.1%) and 4.2% (95% confidence interval 1.0%, -8.8%) at 12 and 36 months, respectively. No significant difference between the subgroups was observed at 12 months. At 36 months, reconstructive modalities showed a significantly lower implant failure rate (1.0%; 95% confidence interval 0.0%, 5.0%; P = 0.04, χ2(1) = 4.1) compared to non-reconstructive modalities (8.0%; 95% confidence interval 2.0%, 18.0%). The mean probing pocket depth was 3.71 mm (95% confidence interval 3.48, 3.94 mm) at 12 months and 3.63 mm (95% confidence interval 3.02, 4.24 mm) at 36 months. The mean marginal bone loss was 3.31 mm (95% confidence interval 2.89, 3.74 mm) at 12 months and 2.38 mm (95% confidence interval 1.01, 3.74 mm) at 36 months. No significant differences between the modalities were observed for bleeding on probing after either of these time points. Cumulative interventions during supportive therapy were reported in 9% of the studies.

Conclusion: Surgical treatment of peri-implantitis results in a low implant failure rate in the short and medium term. No differences were noted between the different interventions with regard to failure rate. Surrogate therapeutic endpoints were improved after treatment, without significant differences between the different modalities. Therapeutic success and/or disease resolution and cumulative interventions during supportive therapy are seldom reported in the literature, but limited long-term outcomes are documented consistently.

Background: The present retrospective study investigates implant retention time in patients who had experienced multiple implant failures and explores possible risk factors.

Materials and methods: Patients who underwent placement of at least two implants and experienced failure of two or more implants between 2004 and 2022 were included in the study population. Both patient- and implant-related risk factors, including age, sex, medical history, medication intake, smoking, alcohol consumption, implant properties and anatomical and surgical factors, were evaluated. Descriptive analysis and univariate and multivariate statistical analysis were performed to assess implant retention time and failure risk, with the level of statistical significance set at 0.05.

Results: A total of 371 patients (178 men and 193 women, median age 63 years) with 3,141 implants were included in the analysis (3.14% of all patients treated since 2004). Out of these implants, 1,090 failures were observed (59.01% of all failed implants at the Academy of Oral Implantology, Vienna, Austria), with a median retention time of 108.11 months. Patients who lost teeth due to periodontitis did not show a tendency towards early implant failure (P > 0.001). Nicotine consumption (P < 0.001), age < 50 years and > 70 years (P < 0.001), maxillary location (P = 0.05), transgingival healing (P < 0.001), no provisional restoration (P = 0.035) and short implant length (P < 0.001) were associated with statistically significantly shorter implant retention times.

Conclusions: Patients with multiple implant failures displayed cluster behaviour and had a median implant retention time of 9 years. Smoking, short implant length, single-stage surgery and immediate loading were all associated with a higher risk of failure, whereas age between 50 and 70 years and tooth loss due to periodontitis were associated with a longer implant retention time.