The International journal of oral & maxillofacial implants最新文献

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.

Purpose: To summarize and analyze all the evidence available concerning marginal bone loss (MBL) and implant failure between tilted and axial implants.

Materials and methods: An electronic literature search was conducted without any language restrictions, and only systematic reviews with meta-analysis or meta-analysis studies were included. Relative risks (RRs) and the differences in mean (MD) were calculated with 95% confidence intervals (CIs) for the assessed outcomes (in mm) of implant failure and MBL.

Results: In total, eight studies were included. Based on the short-term results, a nonsignificant mean difference (MD = 0.00; 95% CI; -0.01-0.02; P value = .75) was recorded between tilted and axial implants supporting full-arch dentures. A significant mean difference was recorded at 3-year follow-up (MD = 0.08 95% CI= 0.05-0.11; P value < .00001) and at long-term follow-up (MD = 0.18; 95% CI = 0.15-0.20; P value < .00001). A nonsignificant difference was observed between tilted and axial implants regarding implant failure (RR = 1.02; 95% CI = 0.85-1.23;P value = .81).

Conclusions: Based on the high- and moderate-quality studies with low risk of bias included in this review, no significant difference in outcome regarding implant failure was observed between tilted and axial implants supporting full-arch or fixed partial dentures.

Purpose: To evaluate the response of human peri-implant soft tissue (PIST) to different healing abutment materials 24 hours after positioning by assessing the expression of genes related to the early connective tissue wound healing response.

Materials and methods: The following four materials were used to create experimental abutments that were mounted on implants placed in five patients (four different abutments in each patient): group A-grade 4 titanium (Ti), group B-grade 5 Ti, group C-zirconia (Zr), and group D-polyetheretherketone (PEEK). Before implant placement, a gingival biopsy (control, CT) sample was obtained using a 2-mm-diameter punch (T0). After 24 hours, PIST biopsy samples were collected using a specifically designed custom-made cutting device. Real-time polymerase chain reaction (PCR) was performed to analyze the expression of the following genes: COL-I, COL-III, MMP-1, TIMP-1, TGF-β1, FN, ITGA4, ITGA5, ITGB1, RAC-1, COL-IV, αSMA, IL-6, and CXCL-1.

Results: Gene expression analysis showed some differences between CT and the experimental groups; however, no significant differences were detected when comparing the experimental groups. COL-I was significantly downregulated in groups A and C compared to CT. Expression of MMP-1 and TIMP-1 increased in all the experimental groups but to a lesser extent in group A. FN, RAC-1, COL-IV, and αSMA were downregulated, especially ingroup A, in which CXCL-1 and IL-6 showed the lowest expression.

Conclusions: The results of grade 4 Ti and Zr abutments seem to be promising, because a lower expression of genes related to inflammation, myofibroblast activation, and extracellular matrix remodeling was observed when compared with grade 5 Ti and PEEK, without triggering a profibrotic response in the early phases of PIST repair.

Purpose: To evaluate the clinical performance of implant-prosthetic rehabilitations carried out using ceramic-coated CAD/CAM titanium abutments.

Materials and methods: Thirty implants were placed in 30 patients and rehabilitated with 30 single crowns attached to CAD/CAM titanium abutments. A conventional procedure was applied, implants were placed after postextraction socket healing, and prosthetic restorations were placed after implant healing. Implant lengths ranged from 6 to 15 mm, and widths were 3.6, 4.2, and 4.8 mm. At the time of prosthesis delivery (T0), after 2 years (T1), and after 5 years (T2), the Plaque Index (PI), bleeding on probing (BoP), pocket probing depth (PPD), marginal bone level (MBL), and pink/white esthetic scores (PES/WES) were evaluated for each implant.

Results: No patient dropped out of the study during the follow-up period. All 30 implants were clinically successful 5 years after prosthesis delivery (survival rate: 100%) and showed no signs of peri-implant infection. Peri-implant soft tissues were in good health (BoP at T2: 0% in 73% of patients; 25% in 13% of patients; 50% in 10% of patients; and 75% in 3% of patients). The mean PPD was 2.05 ± 0.56 mm at T0, 1.992 ± 0.6 mm at T1, and 1.867 ± 0.439 mm at T2. The mean MBL was 0.413 ± 0.440 mm at T0, 0.306 ± 0.388 mm at T1, and 0.263 ± 0.368 mm at T2. The mean PES, WES, and PES/WES indices (7.43 ± 1.04, 7.57 ± 0.82, and 15.00 ± 1.17, respectively) indicate good integration of soft tissues, satisfactory esthetics, and overall positive outcomes.

Conclusions: The success rates, maintenance of MBLs, and periodontal and esthetic indices suggest the validity of implant-prosthetic rehabilitations with CAD/CAM abutments in cases of single crowns.

Purpose: To investigate the effect of lateral sinus floor elevation (LSFE) on sinus membrane (SM) thickness and sinus health in mucosa thickness < 5 mm and > 5 mm.

Materials and methods: LSFE was performed in a prospective controlled clinical trial on two groups with < 5 mm and > 5 mm SM thickness (Groups A and B, respectively) and followed for 6 months. Using preoperative and 6-month postoperative CBCT scans and clinical evaluation, SM thickness changes (primary outcome variable), sinus health, augmented bone height and length (augmentation adequacy), membrane-related variables, and operation time were measured.

Results: Forty unilateral sinus augmentations (n = 20 for both groups) were performed on 40 subjects (72.5% men, mean age of 48.8 ± 7.6 years), and 52 implants were simultaneously placed. The mean preoperative and 6-month SM thicknesses were 1.4 ± 0.9 mm and 1.3 ± 0.6 mm in Group A, respectively, and were 6.8 ± 1.0 and 3.4 ± 1.7 mm in Group B, respectively. The mean postoperative SM thickness significantly decreased (P < .001) only in Group B. The mean SM thickness changes also revealed a noticeable difference between the two groups (P < .001). Augmentation adequacy and membrane perforation rate were similar in both groups. Clinical and radiographic rhinosinusitis was not detected in any of the patients. Bleeding during separation and resistance to elevation were significantly higher in Group B than in Group A (P = .003, P = .001). Surgical time was longer in Group B (12.08 ± 8.26 minutes) than in Group A (8.64 ± 3.70 minutes), without reaching significance (P = .097).

Conclusions: LSFE in thickened mucosa (< 10 mm) and thinner mucosa (< 5 mm) does not cause abnormal changes in the SM and sinus health. LSFE in thickened mucosa results in adequate sinus augmentation. The thickened membrane does not appear to be a contraindication to LSFE.