即刻修复1年后种植体周围边缘骨吸收的临床评价

目的 观察即刻修复种植体的临床存活率和种植体周围边缘骨的变化,对影响种植体即刻修复的相关因素进行初步探讨.方法 选择75名患者行种植后即刻修复,共植入种植体171颗,其中ITI种植体110颗,奥齿泰SSⅡ种植体61颗.在术后即刻、术后6个月和术后12个月行X线检查,评价即刻修复后种植体周围边缘骨的变化.结果 ITI和奥齿泰SSⅡ种植体临床存活率分别为100%～98.4%.即刻修复后种植体周围边缘骨吸收主要发生在修复后6个月内.在上颌骨,2组种植体的边缘骨吸收量差异无统计学意义(P＞0.05);在下颌骨,2组种植体在植入时边缘骨高度和术后6个月骨吸收量差异有统计学意义(P＜0.05).单冠修复组在6～12个月期间的种植体边缘骨吸收更为显著.结论 在获得良好的种植体初期稳定性并进行合理的控制耠力下进行即刻修复,可以取得满意的临床效果.即刻修复后种植体周围边缘骨吸收主要取决于一段式种植体的植入深度.     

Marginal bone loss around three different implant systems: radiographic evaluation after 1 year

Summary  This study was designed to radiographically evaluate the effect of surface macro-and microstructures within the coronal portion of the external hex implant at the marginal bone change after loading. The fifty-four patients included in the study were randomly assigned to treatment groups with rough-surface implants (TiUnite, n  = 45), a hybrid of smooth and rough surface implants (Restore, n  = 45) or rough-surface with microthreads implants (Hexplant, n  = 45). Clinical and radiographic examinations were conducted at the time of implant loading (baseline) and at 1-year post-loading. A three-level mixed-effect ancova was used to test the significance of the mean marginal bone change of the three implant groups from baseline to 1-year follow-up. At 1-year, significant differences were noted in marginal bone loss recorded for the three groups ( P  < 0·0001). The rough surface with microthread implants had a mean crestal bone loss of 0·42 ± 0·27 mm; the rough surface implants, 0·81 ± 0·27 mm; and the hybrid surface implants, 0·89 ± 0·41 mm. Within the limitations of this study, a rough surface with microthreads at the coronal part of implant maintained the marginal bone level against functional loading better than implants without these two features.     

A rough surface implant neck with microthreads reduces the amount of marginal bone loss: a prospective clinical study

Objectives: An intra-individual controlled clinical trial was conducted to evaluate and compare the amount of marginal bone loss (MBL) found around implants of a comparable design, with or without retention grooves (microthreads) or polished necks, during the early stages of healing.
Materials and methods: Forty-eight (48) patients with missing mandibular posterior teeth were treated with two commercially available implants of the same brand (MIS): one with microthreads (S-model) and the other with a polished neck (L-model). MBL around each implant was measured on follow-up radiograms taken 4 months after placement (exposure and crown cementation), and 6 and 12 months after loading.
Results: Forty-six (46) patients completed the study, making 46 implant pairs available for statistical analysis. None of the implants failed to integrate. All the implants displayed some extent of bone loss throughout the follow-up period. At each time point (exposure, 6 and 12 months after loading), the S-model implants displayed statistically significant lower amounts of bone loss (0.22 vs. 0.76, 0.57 vs. 1.22 and 0.9 vs. 1.5 mm, respectively). Other than the type of the implant, no correlation was found between MBL and the implant stability values (PerioTest), dimensions, site of insertion or any of the other collected variables.
Conclusions: Implants with a roughened neck surface and microthreads are more resistant to MBL during the first phases of healing, as compared with implants with a polished neck.     

Alveolar bone remodeling around immediate implants placed in accordance with the extraction socket classification: a three-dimensional microcomputed tomography analysis

Background: Previous studies assessed bone remodeling after a single tooth extraction; however, the effect of multiple contiguous teeth extractions around immediate implant remains unknown. The aim of this microcomputed tomographic investigation is to analyze the alveolar bone remodeling around immediate implants placed in accordance with the extraction socket classification (ESC). Methods: Under general anesthesia, 10 beagle dogs underwent atraumatic tooth extractions. Animals were randomly divided into three groups, with 16 sites per group: 1) ESC‐1, single tooth extraction; 2) ESC‐2, two contiguous teeth extraction; and 3) ESC‐3, more than two contiguous teeth extractions. Immediate implants were inserted in each socket, and postoperative plaque control measures were undertaken. After euthanasia, the jaw segments were evaluated for bone thickness, marginal bone loss (MBL), and bone‐to‐implant contact (BIC) using microcomputed tomography. Results: The mean buccal bone thickness (P <0.05) and MBL (P <0.05) was compromised in jaws in ESC‐3 compared to those in ESC‐1 and ESC‐2. The BIC was significantly higher among jaws in ESC‐1 compared to those in ESC‐2 and ESC‐3 (P <0.05). There was no significant difference in the buccal bone thickness, MBL, and BIC among the groups in the maxilla and mandible. Lingual bone remodeling did not reveal any significant differences among the groups in either jaw. Conclusion: Buccal bone remodeling is significantly more extensive around immediate implants placed in multiple contiguous tooth extraction sites compared to immediate implants placed in single tooth extraction sites.     

A 10-year evaluation of implants placed in fresh extraction sockets: a prospective cohort study

Background: The placement of an implant into a fresh extraction socket has been identified as a reliable technique, allowing a reduction in the time needed for prosthetic rehabilitation. This treatment modality is widely reported in the scientific literature; however, the long-term outcomes and the need for guided bone regeneration (GBR) are still topics of debate. The aim of this prospective study is to evaluate the clinical and radiologic findings from the 10-year follow-up of immediately placed implants, with and without the GBR procedure. Methods: A total of 159 implants in 91 patients are included in this study; 101 implants required a GBR procedure simultaneously with placement. All implants were used to support a single crown restoration. The clinical/radiographic measurements were repeated each year up to the 10-year follow-up. At the 10-year follow-up visit, the papilla index and the apico-coronal location of mid-buccal soft tissue positions were recorded. Results: The 10-year cumulative success rate was 91.8% (87.9% in the non-GBR group and 94.1% in the GBR group). The clinical attachment level (CAL) measurements were stable throughout the study, and 82% of the implants showed marginal bone loss (MBL) of 0.6 to 1.5 mm at the 10-year visit; moreover, these two parameters did not show significant differences between the GBR and non-GBR groups. Seventy percent of the implant sites showed acceptable outcomes in terms of interproximal papilla. The facial gingival level was more apical in the non-GBR group than in the GBR group (P <0.05). Conclusions: The present prospective clinical study shows that implants placed in fresh extraction sockets had a high cumulative success rate, namely 91.8% after 10 years. No differences were detected in survival and success rate of implants whether GBR procedures were performed or not. The CAL, MBL, and marginal level of soft tissue measurements were stable throughout the 10-year evaluation.     

A 3‐year prospective radiographic evaluation of marginal bone level around different implant systems

Summary The aim of this study was to evaluate the change of marginal bone level radiographically around three different implant systems after 3 years in function. Fifty‐four patients were included and randomly assigned to three treatment groups of rough‐surface implants (TiUnite, n = 37), hybrid of smooth and rough‐surface implants (Restore, n = 38) and rough surface with microthread implants (Hexplant, n = 45). Clinical and radiographic examinations were conducted at the time of implant loading (baseline), 1 and 3 years after loading. A three‐level mixed‐effect analysis of covariance (ancova ) was used to test the significance of the mean marginal bone change of the three implant groups. A total 120 of 135 implants completed the study. None of the implants failed to integrate. Significant differences were noted in the marginal bone loss recorded for the three groups (P < 0·0001). At 3 years, the rough surface with microthread implants had a mean crestal bone loss of 0·59 ± 0·30 mm; the rough‐surface implants, 0·95 ± 0·27 mm; and the hybrid surface implants, 1·05 ± 0·34 mm. Within the limitations of this study, rough‐surface implants with microthread at the coronal part might have a long‐term positive effect in maintaining the marginal bone level against functional loading in comparison with implants without these two features.     

Marginal bone resorption around immediate and delayed loaded implants supporting a locator‐retained mandibular overdenture. A 1‐year randomised controlled trial

The aim of this 1‐year study was to evaluate and compare crestal bone loss and clinical outcomes of immediate and delayed loaded implants supporting mandibular overdentures with Locator attachments. In a randomised controlled clinical trial, 36 completely edentulous patients (mean age 59·6 years) who desired to improve the stability of their mandibular dentures were randomly assigned into two groups. Each patient received two implants in the canine area of the mandible after a minimal flap reflection. Implants were loaded by mandibular overdentures either 3 months (delayed loading group, G1) or the same day (immediate loading group, G2) after implant placement. Locator attachments were used to retain all overdentures to the implants. Peri‐implant vertical (VBL) and horizontal (HBLO) bone losses and clinical parameters [plaque scores (PI), gingival scores (GI), probing depths (PD) and implant stability (ISQ)] were assessed at time of overdenture insertion (T0), 6 months (T6) and 12 months (T12) after overdenture insertion. After 12 months of overdenture insertion, two implants (5·5%) failed in G2. Vertical bone loss was significantly higher in G2 compared with G1, while HBLO demonstrated insignificant differences between groups. All clinical parameters (PI, GI, PD and ISQ) did not differ significantly between groups. Vertical bone loss was significantly correlated with PD and HBLO. Immediately loaded two implants supporting a Locator‐retained mandibular overdenture are associated with more vertical bone resorption when compared to delayed loaded implants after 1 year. Clinical outcomes do not differ significantly between loading protocols.     

Marginal bone loss one year after implantation: a systematic review of different loading protocols

The aim of this study was to analyse the influence of different loading protocols on marginal bone loss (MBL). The outcomes of different implant loading protocols were assessed at 1 year after implantation, with focus on MBL; protocols included immediate, immediate non-occlusal, early, and conventional loading. The search strategy resulted in 889 studies. Twenty-two of these studies fulfilled the inclusion criteria. Among the included studies, the lowest MBL was for immediately loaded implants (0.05 ± 0.67 mm) and the highest for immediate non-occlusally loaded implants (1.37 ± 0.5 mm). The results of the meta-analysis showed an estimated mean MBL of 0.457 mm (95% confidence interval (CI) 0.133–0.781) for immediate loading, 0.390 mm (95% CI 0.240–0.540) for immediate non-occlusal loading, 0.488 mm (95% CI 0.289–0.687) for early loading (>2 days to <3 months), and 0.852 mm (95% CI 0.429–1.275) for conventional loading (>3 months) implant protocols. The lowest decrease in 1-year implant survival per millimetre increase in MBL was observed for immediate loading and the highest for conventional loading. Conventional loading showed a significantly higher MBL than the other three loading protocols. This systematic review and meta-analysis indicates that the immediate loading protocol is a reasonable alternative to the conventional loading protocol.