Clinical Oral Implants Research最新文献

Objective: To determine the effect of polydeoxyribonucleotide (PDRN) on endosinus bone regeneration in a rabbit sinus model at sequential healing time points.

Materials and methods: Eighteen New Zealand white rabbits were used. Bilateral sinus floor elevation (SFE) was performed. Two groups were randomly assigned to each sinus: (1) test group, in which SFE was performed using collagenated bone substitute material soaked with PDRN (concentration 2.0 mg/mL, dose 0.5 mL), and (2) control group, in which SFE was performed using collagenated bone substitute material only. The experimental animals were sacrificed at 2, 4, and 8 weeks (n = 6 at each healing time point). Microcomputed tomography (micro-CT), histologic, and histomorphometric analyses were performed.

Results: The micro-CT analysis revealed statistically significant increases in the mineralized tissue volume between 4 and 8 weeks (p < 0.05). Histologically, no specific intergroup difference was found in the pattern of new bone formation. Histomorphometrically, the area of newly formed bone (NB) was larger in the test group than in the control group at all healing time points (1.4 vs. 1.2 mm² at 2 weeks, 3.4 vs. 1.9 mm² at 4 weeks, and 5.7 vs. 4.5 mm² at 8 weeks; median value), but the difference was statistically significant only at 4 weeks (p < 0.05). NB in set regions of interest (ROI_C, ROI_W, and ROI_M) tended to be greater in the test group than in the control group without statistical significance (p > 0.05).

Conclusions: PDRN appeared to enhance new bone formation at all healing time points, but the improvement was statistically significant only at 4 weeks.

Objective: To determine the in vitro effects of minocycline on human gingival fibroblasts (HGFs), its clinical impact on early wound healing after implant placement, and its potential mechanism of action.

Methods: First, we evaluated the in vitro proliferation, migration, and collagen production of HGFs treated with different concentrations of minocycline, as well as the underlying mechanism. Subsequently, we conducted a clinical trial and randomly assigned 40 partially edentulous patients to either the test (minocycline hydrochloride treatment) or control (blank control) group immediately after implant surgery. The early wound healing score (EHS), pain index, gingival index (GI), modified sulcus bleeding index (mSBI), and peri-implant crevicular fluid samples were assessed or collected 3 and/or 7 days after surgery.

Results: In vitro, 1 μg/mL minocycline promoted the proliferation, migration, and collagen production of HGFs. Minocycline inhibited collagen degradation by downregulating the expression of matrix metalloproteinase-2 (MMP-2) and MMP-14 and upregulating tissue inhibitors of metalloproteinases-2. However, higher concentrations of minocycline, 10 and 100 μg/mL, exhibited adverse effects. In the randomised clinical trial, the test group showed significantly better clinical outcomes compared to the control group, with higher EHS and lower GI, mSBI, concentrations of IL-1β, IL-10, and TNF-α, and relative abundance of Streptococcus and gram-negative anaerobic bacteria.

Conclusions: Small doses of minocycline (1 μg/mL) promoted the proliferation and migration of HGFs and inhibited collagen degradation in vitro. Locally delivered minocycline after implant surgery improves clinical outcomes by promoting early wound healing, relieving the inflammatory response, and decreasing early colonisation of gram-negative anaerobic bacteria.

Trial registration: This clinical trial was registered in the Chinese Clinical Trial Registry (registration number: ChiCTR2100044680).

Objective: The objective of this study is to investigate the influence of metal artifact reduction (MAR) on two cone beam computed tomography (CBCT) units in the evaluation of bone graft loss adjacent to titanium (Ti) and zirconium (Zr) implants.

Material and methods: Twelve Ti and twelve Zr implants were placed in the posterior region of dry human mandibles. Bone graft was applied to the level of the cover screw. Bone graft loss was simulated in half of the sample (6 Ti and 6 Zr) by removing the graft material up to the third implant thread on the buccal surface. CBCT images were acquired on two units, varying the application of MAR (OP300-off and on; Eagle 3D-standard, intermediate, and extreme). The images were assessed by five evaluators that scored the presence of graft loss according to a 5-point scale. The diagnostic values were calculated and compared by non-parametric tests with a significance level of 5%.

Results: Higher diagnostic values were achieved with MAR activated in the OP300 unit, for Ti and Zr (p < 0.05). On the Eagle 3D unit, MAR in extreme mode resulted in lower diagnostic values for both types of implants (p < 0.05). The diagnostic values of Ti implants were higher than Zr implants (p < 0.05).

Conclusion: The application of MAR influences the diagnosis of bone graft loss adjacent to Ti and Zr dental implants. However, the extreme mode of MAR in the Eagle 3D unit can impair the diagnostic task in both types of implants and should be avoided.

Objectives: This retrospective study aimed to evaluate the clinical outcomes associated with zygomatic implant (ZI) rehabilitation in partially atrophic edentulous maxillae over a mean follow-up period of more than 10.3 years.

Methods: All consecutive patients underwent ZI rehabilitation between 1999 and 2020, with a minimum follow-up period of 3 years. The primary outcome was the implant survaival rate. Secondary outcomes included the prosthesis success rate, complications, and Oral Health-Related Quality of Life.

Results: Of the 21 patients, treated with 27 ZIs and 48 conventional implants (CIs), 9 (42.9%) were females. The mean follow-up was 10.3 ± 5.7 years (range 3.2-23.4). ZI and CI survival rates were 100% and 97.9%, respectively, with one CI that failed. Eleven patients received 12 CIs placed in the pterygoid and tuberosity region. Most of the implants (81.33%) were immediately loaded, with 17 patients (80.9%) receiving 21 acrylic bridges. Of the total of 26 definitive prosthesis, the success rate was 96.1%. Local inflammation (n = 2) and soft tissue recession (n = 1) were reported as complications, occurring at a mean follow-up of 4.5 and 3.2 years, respectively. The mean score of the OHIP-14 questionnaire was 1.19 ± 1.99.

Conclusions: Unilateral ZI rehabilitation was a predictable option for patients with partially atrophic edentulous maxilla who have experienced previous graft or implant failures, or who require immediate loading. Splinting the ZI with CI for restoration appeared to be essential in unilateral ZI treatment. Complications were infrequent and could be managed effectively, with patient-reported outcomes indicating normalization in quality of life.

Objective: The objective of this study was to compare open versus closed healing of soft and hard tissue following alveolar ridge preservation (ARP) procedures in damaged extraction sockets.

Materials and methods: ARP was performed in five mongrel dogs using collagenated deproteinized bovine bone mineral (cDBBM) and a resorbable non-cross-linked collagen membrane (NCCM) in damaged extraction sockets, with each socket entrance left either open (open group) or closed (closed group). Clinical wound epithelization at the socket entrance and the dimensions of keratinized tissue were evaluated over time. Additionally, the augmented ridge dimensions and new bone formation were assessed radiographically and histologically at 8 weeks after surgery.

Results: The dimensions of the socket entrance gradually decreased in the open group, and wound epithelization was almost complete within 4 weeks. The mucogingival junction was maintained more apically in the open group than in the closed group (0.14 ± 0.40 mm vs. -0.86 ± 0.71 mm [mean ± SD], p < 0.05). The augmented ridge dimensions did not differ significantly between the open and closed groups (93.1% ± 5.4% vs. 88.3% ± 11.2%, p > 0.05). Histological analyses revealed no significant differences in the amount of newly formed bone. However, membrane resorption in the crestal region was more pronounced in the open group.

Conclusion: Open and closed healing approaches for ARP in extraction sockets with damaged buccal wall resulted in similar ridge dimensions and new bone formation. However, there was less reduction of the buccal bone crest and wider keratinized tissue width after open healing.

Objectives: To evaluate the influence of the three-dimensional (3D) printing technology, material, sterilization, and disinfection on the accuracy of guided surgical templates.

Material and methods: Fifty printed resin surgical templates were designed and fabricated using a digital light processing 3D printer with a photopolymerizing resin, and 50 printed metal surgical templates were designed and fabricated using a selective laser melting 3D printer with a titanium alloy. Templates from both groups were randomly divided into five subgroups involving different sterilization and disinfection procedures. The group without any sterilization or disinfection procedure served as the control group, whereas the other groups were used as the study groups (hydrogen peroxide gas plasma sterilization, 5% povidone-iodine disinfection, 75% ethyl alcohol disinfection, and steam autoclave sterilization). Implant simulations were performed on the 3D-printed resin models, and postoperative impressions were acquired with scan bodies attached to the implants. All surgical templates were digitally scanned. The root mean square was used to determine and quantify fabrication accuracy and reproducibility, and the definitive and planned implant positions were compared.

Results: The printed resin templates exhibited lower fabrication accuracy and reproducibility, as well as higher 3D deviations, after steam autoclave sterilization (p < 0.001); however, the printed metal templates were not affected by the different sterilization or disinfection procedures (p > 0.05).

Conclusions: Printed metal surgical templates are viable alternatives for guided implant surgery. Preoperative steam or gas plasma sterilization is recommended, especially for metal templates, as resin templates show deformation and decreased accuracy after steam sterilization.

Trial registration: chictr.org.cn number: ChiCTR2400081334.