The International journal of oral & maxillofacial implants最新文献

Purpose: This study aims to assess the differences between a leukocyte- and platelet-rich fibrin (L-PRF) and deproteinized bovine bone mineral block and a combination of 50% autogenous bone (AB) and 50% deproteinized bovine bone mineral (DBBM) as grafting material for horizontal guided bone regeneration (GBR).

Materials and methods: This randomized double-blind split-mouth clinical trial included 13 subjects requiring bilateral horizontal bone augmentation. Each patient received both treatment modalities: one side of the jaw was treated by GBR with the L-PRF and deproteinized bovine bone mineral block, and the other side with a 50/50 mixture of AB and DBBM. Cone beam computed tomography (CBCT) scans were used to evaluate horizontal bone width (HBW) and buccal bone thickness (BBT) at various time points: baseline (T0), immediately post-augmentation (T1), at implant placement (T2), and one year after abutment connection (T4). Bone sounding (BS) was also used to verify CBCT measurements.

Results: No statistically significant differences were found in HBW gain between test (L-PRF) and control (AB/DBBM) sites at any timepoint. Both sites showed significant HBW loss post-implant placement, with more bone volume lost at higher crestal levels (Sh0 > Sh2 > Sh4). At the Sh2 level, 48.8% of the HBW gain at T1 was lost by T4 in test sites, and 46.2% in control sites. Similarly, BBT at Sh2 reduced from 4.7 ± 1.0 mm to 1.3 ± 1.5 mm in test sites and from 2.1 ± 1.0 mm to 0.9 ± 0.8 mm in control sites. Both groups of sites had one complication, resulting in a 91.6% success rate for both treatments. The cumulative survival rate of implants was 100% at 16 months, with a mean interproximal bone level (IBL) loss of 0.2 ± 0.9 mm and 0.1 ± 0.6 mm for test and control sites, respectively.

Conclusions: No statistically significant differences were found between the AB/DBBM composite graft and the L-PRF and bovine bone mineral block for horizontal GBR. Significant resorption of grafted volume occurs within 25 months, continuing post-implant placement. Further research with larger sample sizes is needed to confirm these findings and optimize GBR techniques.

The release of titanium nanoparticles during implant placement in dense bone is a significant concern, as it can potentially have adverse effects on the peri-implant tissues and an impact on the etiology of peri-implant diseases. The objective of this study was to examine the presence of titanium nanoparticles at the bone-implant interface during implant placement utilizing the bone condensation technique in vitro. Artificial Type IV bone slices (4mm thick) were securely held in place with a vice. Two groups of implants were placed. One group (test group) was placed under the condensation technique using cylindrical osteotomes. The other group (control group) was placed following the traditional surgical protocol. Implants were placed in parallel between bone slices held in a vice. Three groups of implant designs (6 implants in each group) were inserted into the bone. Two implant designs consisted of implants made of pure titanium (grade 4), while the third implant design group was constructed of titanium alloy (Ti6Al4V). Subsequently, the blocks were separated, and the peri-implant bone interface was qualitatively evaluated for titanium presence using X-ray-fluorescence spectrometry (XFS) at the coronal, middle, and apical thirds of osteotomies (n=12/ implant system). Descriptive statistical analysis showing the mean values (+/-SD) of titanium nanoparticles was performed. No detectable titanium levels were identified in the control group of titanium alloy-implants compared to pure titanium-implants. In contrast, the test group of all implant systems showed presence of titanium nanoparticles in coronal, middle, and apical thirds. Our results indicate that bone condensation technique is associated with titanium release during implant placement in vitro. These findings were shown for both pure titanium- and titanium alloy-dental implants.

Purpose: This systematic review and meta-analysis aims to analyze the risk of prosthesis complications across different implant diameters.

Materials and methods: An electronic search across PubMed (MEDLINE), Embase, Scopus, and Cochrane Central Register of Controlled Trials until December 2023 was performed. Studies comparing implant prosthesis complications among extra-narrow (<3.0 mm), narrow (≥3.0 to <3.75 mm), standard (≥3.75 to <5 mm), and wide-diameter (≥5 mm) implants were included. Meta-analyses were performed to evaluate the risk ratio of prosthesis complications across different diameters, particularly in non-full arch implant-supported fixed dental prostheses (ISFDP).

Results: Eighteen clinical studies were included. In non-full arch ISFDP, the most prevalent complication was screw loosening in narrow, standard, and wide-diameter implants (17.28%, 4.08% and 12.45%, respectively), and decementation (3.4%) in extra-narrow diameter implants. In implant overdentures, extra-narrow, narrow and standard-diameter implants demonstrated high rates of retentive cap wear (58.33%, 80.49% and 70%, respectively), whereas wide-diameter implants had 16.67% overdenture repair. The meta-analyses showed a risk ratio of 0.20 (95% confidence interval= 0.04 to 0.94, p= 0.04) and 0.17 (95% CI= 0.06 to 0.45, p< 0.0004) for abutment fracture in single crowns and ISFDP comparing narrow versus standard-diameter implants. No significant differences in risk ratios were observed for screw loosening, decementation, porcelain chipping, fracture, or screw fracture among the different diameter groups.

Conclusions: This systematic review highlights that screw loosening and retentive cap wear are the most common prosthesis complications in ISFDP and overdentures, regardless of implant diameter. While narrow-diameter implants have a lower risk of abutment fracture compared to standard-diameter implants, clinicians should carefully consider patient characteristics, implant locations, and abutment features when selecting the ideal implant diameter.

Purpose: This retrospective clinical study aims to analyze single-unit implant-supported restorations' clinical and radiographic outcomes comprehensively.

Materials and methods: In this retrospective study, patients who had undergone 12 months of implant-supported singleunit fixed prosthetic treatment were scanned from the archives, and a hundred patients were included in the study. Implant success and survival rates were assessed according to the consensus decisions published at the International Oral Implantology Congress in 2007. Prosthetic complications such as chipping, screw loosening, and decementation were also evaluated. In addition, success/survival rates and prosthetic compositions were associated with some surgical and prosthetic parameters.

Results: According to the success/survival criteria, 88% of the implants were successful, 10% had satisfactory survival, and 2% had compromised survival. The risk of satisfactory or compromised survival was 62.5 times higher in individuals with inadequately keratinized mucosa compared to those with adequately keratinized mucosa (p < 0.001). It was also 5.736 times greater for extractions due to periodontal disease versus endodontic reasons (p = 0.010) and 4.629 times higher for implants with diameters less than 3.75 mm compared to those between 3.75 mm and 5 mm (p = 0.037). Screw loosening was observed in 15% of the evaluated restorations, decementation in 13% and chipping in 4%, and the risk of screw loosening was 4.444 times higher for screw retention abutments compared to standard abutments (p=0.015).

Conclusion: Insufficient keratinized mucosa, periodontal problems leading to tooth extractions, and the use of narrowdiameter implants can negatively affect the success of implant procedures. Loosening in screw-retained restorations is due solely to screw loosening, which is a high risk for screwretained restorations. Loosening in cement-retained restorations, on the other hand, is caused by the decementation of the prosthetic restoration or loosening of the abutment screw supporting the restoration.

Purpose: Implant stability (IS) is crucial to the success of any implant-based therapy. The present work aimed to determine the relationship between primary and secondary stability and a range of variables.

Material and methods: This retrospective cohort study included a total of 169 patients, who received 445 dental implants. A case history for each participant was created. Data collection included each patient's age, implant design, length and diameter, bone type, and surgical factors. Implant Stability Quotient (ISQ) values were measured at baseline (T0: primary stability) and T1 (secondary stability). To calculate the ISQ values at T0, T1 and their differences in the variables age, design, length and diameter, a multivariate ANOVA test was performed to determine which variables acted as confounding factors and to adjust the ISQ values to these variables.

Results: The main variables age, design, length and diameter were adjusted to their confounding factors. Regarding primary (T0) and secondary (T1) stability, statistically significant differences (p<0.05) were only found in implant diameter, with the larger the diameter, the greater the stability. In all the other main variables, no statistically significant differences were found for primary and secondary stability.

Conclusions: It may be concluded, within the limitations of the study, that the implant diameter variable is the one that significantly affects the primary and secondary stability of the implant.

Purpose: The available scientific evidence on the effectiveness of the surgical treatment of peri-implantitis is limited. The aim of this study was to assess the risk of recurrence or disease progression in patients with peri-implantitis that underwent surgical treatment.

Materials and methods: A retrospective cohort study was carried out in patients subjected to peri-implant surgery between 2015 and 2021, and with a minimum follow-up of 12 months. Data were analyzed using simple binary logistic regression models at patient level and generalized estimation equations at implant level.

Results: A total of 34 patients and 103 implants were analyzed (70 undergoing resective techniques and 33 regenerative procedures). Fifteen patients (44.12%) experienced peri-implantitis recurrence and one patient (2.9%) lost one implant. No differences were found between the surgical techniques (p = 0.56). A history of periodontitis (ORa = 4.62; 95%CI: 1.14 to 18.75; p = 0.032), maxillary location (ORa = 9.69; 95%CI: 1.81 to 51.87; p = 0.008) and two implants treated per procedure (ORa = 31.68; 95%CI: 3.91 to 256.54; p = 0.001) were seen to increase the risk of recurrence.

Conclusions: Almost half of all patients (44%) undergoing surgical treatment of periimplantitis will present disease progression or recurrence. This risk seems to be higher in patients with several treated implants, with a history of periodontal disease, or when the maxilla is involved.

Purpose: To explore the contribution of paired-related homeobox 1-positive (Prrx1+) cells to the implant-induced osseointegration process in adult alveolar bone and the potential underlying mechanisms.

Materials and methods: Crerecombinase-induced lineage tracing and cell ablation were conducted in a murine dental implant model. Scratch and transwell assays were used to assess MC3T3-E1 cell migration after paired-related homeobox 1 overexpression. Single-cell RNA sequencing was applied to identify potential genes involved in Prrx1+ cell-driven osteogenesis.

Results: Prrx1+ cells were observed to accumulate in the peri-implant area in a time-dependent manner; the number of these cells was found to reach its maximum on day 14. Osseointegration in mice was noticeably impaired after ablation of Prrx1+ cells. Further, it was discovered that Prrx1 promotes MC3T3-E1 cell migration, a process which is indispensable for sound healing of peri-implant tissue. Finally, semaphorin 3C (Sema3C) was detected exclusively and abundantly expressed by Prrx1+ cells. Knockdown of Sema3C in Prrx1+ cells significantly weakened their osteogenic potential.

Conclusions: Our data suggest that Prrx1+ cells contribute to the osseointegration process under stress stimulation and Sema3C may play a critical role in Prrx1+ cell-driven osteogenesis. Prrx1 could significantly promote MC3T3-E1 cell migration.

Purpose: To evaluate the feasibility of reversing a primary failure through therapeutic mechanical stimulation induced by transcutaneous application of acoustic waves (extracorporeal shockwave therapy [ESWT]) in the peri-implant tissues.

Materials and methods: This clinical report evaluates the outcome of a new protocol proposed to treat a primary failure (loosened oral implant): application of three cycles of ESWT (one session per week for 3 consecutive weeks) with an equivalent positive energy of 0.18 mJ/mm2 (therapeutic dose: 2,000 pulses, 8 Hz, 4.0 bar). Standardized intraoral radiographs and CBCT scans were taken, the implant stability quotient (ISQ) was determined, and clinical evaluations were performed.

Results: It was possible to verify a progressive increase in ISQ values after the ESWT protocol: 17 initially, 46 at 2 months, and 68 at 4 months. This led to successful implant prosthetic rehabilitation (35 Ncm). Follow-up evaluations at 6 years confirm that the new bone-implant interface is preserved and that ESWT is a safe, noninvasive treatment.

Conclusions: In the context of the new dynamic model of osseointegration (the foreign body equilibrium), this represents the first report of a host-implant equilibrium reestablished after an early implant failure process. However, more studies are needed to determine both the medical device and the most effective therapeutic range for clinical applications of this technology in oral implantology.

Purpose: To evaluate over 5 years the mesial, distal, palatal, and buccal bone levels as well as the buccal bone thickness surrounding scalloped implants that were immediately placed and loaded with provisional crowns fixed on final prefabricated abutments.

Materials and methods: A total of 18 implants were placed and immediately loaded using CAD/CAM technology in 18 patients to replace a single tooth in the anterior maxilla. The marginal bone levels around the scalloped implant necks were measured mesially and distally using intraoral standardized radiographs after crown placement as well as at the 1-, 3-, and 5-year follow-ups. CBCT para-axial cut images were used to measure the bone level buccally and palatally from the implant neck to the bone-to-implant contact (BIC) 5 years after loading. These images were used to evaluate the thickness of the buccal bone at the implant neck and 4 mm apically both immediately after implant placement (T0) and 5 years later.

Results: All implants were assessed clinically and radiologically after 5 years. No implant failure was recorded, and the average marginal bone variation for mesial and distal sites was as follows: 0.114 ±0.135 mm at crown cementation, 0.239 ± 0.158 mm 1 year later, 0.233 ± 0.182 mm 3 years later, and 0.180 ± 0.182 mm 5 years later. Our findings indicate that at T0, the average thickness of the buccal bone was 2.27 mm at the implant neck (M0; ranging from 1.9 to 2.4 mm) and 2.33 mm at 4 mm apical to the implant neck (M1; ranging from 1.9 to 2.9 mm). At 5 years postoperative (T4), the mean had decreased to 1.94 mm at M0 (ranging from 1.7 to 2.3 mm) and 2.14 mm at M1 (ranging from 1.8 to 2.4 mm). After 5 years of functional loading, the mean changes at the buccal and palatal bone for all implants were +0.187 ± 0.52 mm and +0.06 ± 0.38 mm, respectively. Minor prosthetic problems were observed over the 5 years, including incisal ceramic chipping in two crowns and replacement of two crowns due to esthetic reasons after 1 year. No loosening of crowns or abutments was reported.

Conclusions: Scalloped-neck implants demonstrated a comparable behavior to regular-neck implants with similar designs in immediate placement and temporization protocol over a 5-year period.

Purpose: To conduct a systematic review and meta-analysis to examine the impact of titanium (Ti) base-supported single-implant restorations on peri-implant conditions.

Materials and methods: Six randomized controlled trials (RCTs) comprising 274 implants met the inclusion criteria and were chosen for data analysis. A random-effects model was employed for the meta-analysis.

Results: Data from this study revealed that the Ti-basegroup exhibited a small but statistically significant increase in peri-implant marginal bone loss (MBL; mean difference = 0.088 mm; 95% CI = 0.003 to 0.17; P = .041) compared to the one-piece abutment group. These effects were consistent in the subgroup analysis of regularly threaded implants compared to the microthreaded subgroup. No significant differences were observed between the Ti-base group and the abutment group concerning probing depth (PD), bleeding on probing (BoP), and the risk of prosthetic-related complications.

Conclusions: The use of a Ti-base in a single implant-supported restorationis associated with a slight increase in peri-implant MBL, while other peri-implant health parameters show no significant correlation. Therefore, the evidence of the impact that Ti-bases have on the peri-implant conditions of single implant-supported restorations is insufficient based on the findings of the present meta-analysis.