Clinical Implant Dentistry and Related Research最新文献

Introduction

This study assesses the effects of different three-dimensional (3D) print offsets of sleeves on sleeve and implant placement trueness in guided implant surgery.

Methods

Twenty-five sleeves were installed on 3D-printed surgical guides, with sleeve offsets of 0.02, 0.04, 0.06, 0.08, and 0.10 mm (five groups with five sleeves per group). The actual surgical guides were scanned to generate digital files, which were compared with the reference group based on design positions. The experimental verification and evaluation method involves assessing sleeve installations and measuring the deviations between the actual position of the sleeve and implant compared with the reference group.

Results

The sleeve installations in the 0.02-mm offset group were not acceptable, as there were visible cracks in the sleeve; in the case of the 0.04-mm offset group, there were also installation difficulties. At the sleeve position level, there were larger deviations in the 0.10-mm offset group, whereas the 0.08-mm group had smaller deviations in the labial and palatal directions (p < 0.05). At the implant level, the 0.10-mm offset group showed a significantly larger deviation (labial: 0.453 ± 0.165 mm; palatal: 0.399 ± 0.160 mm; p < 0.05). As for the mesial–distal direction, there were no significant differences between the groups.

Conclusions

Print offsets of sleeves had a significant effect on the ease of installation and the placement accuracy of sleeves and implants. Under the printer and sleeves conditions used in this experiment, smaller offsets (0.02 and 0.04 mm) caused installation difficulties and misalignments. Larger offsets (0.10 mm) created noticeable deviations. Sleeve offsets of 0.06 and 0.08 mm provided a balance between ease of installation and high placement trueness, making them more suitable in this experiment. Excessive or insufficient print offsets of sleeves can affect installation conditions and positional trueness of sleeves and implants.

Introduction

This study investigated the impact of sinus membrane thickening and perforation on graft remodeling following osteotome sinus floor elevation (OSFE).

Materials and Methods

A total of 136 patients who received single implants with simultaneous OSFE were retrospectively analyzed and categorized based on preoperative sinus membrane thickness: membrane thickening (MT; > 2 mm, n = 38) and normal thickness (NT; ≤ 2 mm, n = 98). Cone-beam computed tomography was used to assess residual bone height and membrane thickness. Periapical radiographs obtained immediately postoperatively (T1) and at final follow-up (T2) were used to quantify sinus bone gain and apical graft height. The incidence of membrane perforation and implant survival was also documented.

Results

Implant survival rates were comparable between groups (MT: 97.4%, NT: 99.0%, p = 0.485). The incidence of membrane perforation occurred significantly more frequently in the MT group than in the NT group (21.1% vs. 6.1%, p = 0.010). Although final sinus bone gain was similar, apical graft resorption was significantly greater in the MT group compared to the NT group (2.3 ± 0.4 mm vs. 1.8 ± 0.6 mm; p < 0.001), resulting in a higher incidence of complete apical bone coverage loss (39.5% vs. 16.3%, p = 0.004). Furthermore, membrane perforation increased apical graft resorption risk regardless of membrane thickness.

Conclusions

Sinus membrane thickening is associated with increased risk of perforation and greater apical graft resorption following OSFE. Thorough preoperative evaluation and careful surgical technique are essential to optimize outcomes, particularly in cases with thickened membranes.

Background

While dynamic navigation systems demonstrate superior precision in implant placement, the influence of variations in optical tracking technology on accuracy warrants further investigation.

Purpose

To compare the accuracy of dynamic navigation for implant placement using active infrared (AI), passive infrared (PI), and passive blue light (PB) optical tracking technologies. The null hypothesis is that there is no significant difference between the three alternative optical tracking technologies.

Materials and Methods

Three surgeons placed implants on 10 models using AI, PI, and PB optical tracking systems. Implants were placed on two sites per model (mandibular central incisors and mandibular first molar), with 180 implants assigned to be placed into 90 mandible models. The planned and placed implant positions were superimposed to assess procedural accuracy.

Results

The mean coronal, apical, and axial deviations for all implants were 0.82 ± 0.02 mm, 0.92 ± 0.02 mm, and 1.56° ± 0.06°, respectively. In the mandibular left central incisors, the coronal, apical, and axial deviations of the PB and AI groups and the PB and PI groups were significantly different (p < 0.032, p < 0.001, p < 0.001, respectively, and both p < 0.001). In the mandibular left first molar, the coronal, apical, and axial deviations of the PB and PI groups were significantly different (p < 0.001, p < 0.001, p = 0.003, respectively). The coronal and apical deviations of the PB and AI groups exhibited statistically significant differences (both p < 0.001).

Conclusions

The PB optical tracking system outperformed the AI and PI optical tracking systems regarding dynamic navigation accuracy, while the AI and PI optical tracking systems were comparable. All systems exhibit sufficient accuracy in vitro.

Objective

The current trial assessed for the first time radiographic and histological alterations, following alveolar ridge preservation (ARP), using autogenous demineralized dentin graft carried in 0.2% high molecular weight sodium hyaluronate (ADDG+HA; test group) versus autogenous demineralized dentin graft (ADDG, control group) alone.

Material and Methods

Thirty patients (n = 30) with non-restorable single-rooted teeth were randomly assigned into two groups (n = 15/group). Following extraction, ARP was performed using either ADDG solely or ADDG+HA. Bucco-lingual alveolar ridge width (BLRW; primary outcome), buccal (BRH) and lingual ridge height (LRH), percentage of newly formed bone, soft tissue and residual graft in human biopsies histologically, as well as patients' pain and discomfort (all secondary outcomes) were assessed after 6 months at the time of implant placement. Sample bone core biopsies were further collected, processed, and histomorphometrically and SEM analyzed.

Results

For the ADDG and ADDG+HA groups, the alveolar ridge dimensional changes were comparable, being −1.21 ± 0.77 mm and −1.18 ± 0.86 mm in BLRW, −0.89 ± 0.74 and −0.83 ± 0.85 mm in BRH, and −0.9 ± 0.76 mm and −1.05 ± 1.18 mm in LRH respectively (p > 0.05). Clinically, no complications, pain, or inflammatory responses were reported. Histologically, all samples demonstrated bone growth and socket bone fill, while the ADDG+HA group showed a significantly greater presence of mineralized mature bone, which accounted for 33% ± 8.1% of the specimen after 6 months.

Conclusions

Both ADDG and ADDG+HA demonstrated comparable outcomes in terms of ARP. HA amalgamation with ADDG appears to enhance bone mineralization and maturation, yet without a significant impact on dimensional changes during ARP procedures.

Trial Registration: NCT05613075

Purpose

The objective of this study was to compare the detachment surfaces of Schneiderian membrane elevation of 4–8 mm by transcrestal technique using hollowed osteotomes on human cadavers with 4 mm residual bone height.

Methods

The study followed the CACTUS (ChAracteristics of Cadaver Training and sUrgical Studies) guidelines. Thirty-four heads with maxillary bilateral edentulous posterior zones and type IV bone (a residual bone height of 4 mm) were selected using cone beam computed tomography (CBCT) scans. Heads were randomly allocated to a group and both sinuses received the same treatment. A sinus floor elevation was performed on the 68 sites using new hollowed osteotome (C.M.C Tech, IBS Implant, Daejeon, South Korea). Samples were divided into two groups: Group 1: sinus elevation of 4 mm; and Group 2: sinus elevation of 8 mm. A postoperative CBCT was performed to analyze membrane integrity and to assess the membrane detachment in mesiodistal and buccopalatal plane.

Results

Of the 68 membrane elevations, only 4 were associated with perforations; 2 occurred in each group. The detachment surface variations between group 1 and group 2 were linear in all directions (Pearson correlation coefficient ρ = 0.99). The Student's t-test unveiled significant differences in detachment surfaces between group 1 and group 2 in all directions (p < 0.001). The ratio of detachment surface group 2/group 1 was homogeneous in all directions (1.5 ≤ r ≤ 1.54). The quality of Schneiderian membrane elevations of 4–8 mm by transcrestal technique was similar using the hollowed osteotomes on human cadavers with 4 mm residual bone height.

Conclusions

In a transcrestal approach using this new-generation osteotome, sinus membrane elevations of 8 mm were performed with a low perforation rate in cadavers. The use of the new hollowed osteotome allowed a Schneiderian membrane elevation of up to 8 mm in a safe and reproducible manner. This transcrestal elevation protocol could increase the indications of the technique, especially concerning single implant restorations and for frail patients with significant medical history for whom a lateral approach would be too invasive.

Background

Immediate implant placement provides an effective solution for replacing a single maxillary anterior tooth, offering several distinct advantages. Screw-retained implant crowns are often favored for their biological benefits, particularly their elimination of excess cement, which reduces the risk of peri-implant complications. However, their application is restricted when the screw channel's access hole must be positioned in a visible area, as this would undermine the aesthetic outcome, a common challenge in immediate implant placement scenarios.

Purpose

To evaluate the 5-year clinical, radiographic, aesthetic, and patient-reported outcomes of angulated screw-retained versus cemented implant crowns following immediate implant placement in the aesthetic region.

Material and Methods

This prospective cohort study included a 5-year follow-up. Eligible patients were divided into two groups according to the type of restoration: angulated screw group (AG) and the cemented group (CG). Implant survival, bleeding on probing (BOP%), probing depth (PD), marginal bone loss (MBL), buccal bone thickness (BBT), mechanical complications, pink esthetic score (PES), and patient's satisfaction assessed by visual analog scale (VAS) were evaluated at the 5-year follow-up.

Results

A total of 38 patients with 38 implants (AG = 20; CG = 18) attended the 5-year examination. After 5 years of loading, the implant survival rate was 100% in both groups with 2 cases of screw loosening in AG (13%) and 1 case of retention loss in CG (5%). No significant difference in BOP% was found between the 2 groups (mean, 18.33% ± 27.52% vs. 24.07% ± 26.34%, p = 0.331). Furthermore, the comparison of PD (3.28 ± 0.87 vs. 2.81 ± 0.75 mm, p = 0.112), MBL (0.38 ± 0.42 vs. 0.35 ± 0.32 mm, p = 0.633), BBT (1.87 ± 0.55 vs. 1.77 ± 0.61 mm, p = 0.613), PES (9.50 ± 2.30 vs. 9.61 ± 1.98, p = 0.942), and VAS (8.60 ± 0.88 vs. 8.56 ± 0.78, respectively, p = 0.96) revealed no significant differences.

Conclusion

Both treatment options can provide high implant survival, achieve acceptable clinical, radiographic, and aesthetic outcomes, and obtain a high level of patient satisfaction, with no significant differences observed after 5-year function.

Background

Static computer-assisted implant surgery (s-CAIS) utilizes 3D imaging data to guide implant placement with high precision. Accurate segmentation of CBCT and intraoral scan data is crucial to creating reliable anatomical models. While AI-driven segmentation has emerged as a promising solution to reduce manual workload, its performance is hindered by technical and algorithmic limitations.

Objective

To evaluate the accuracy and limitations of AI-based segmentation in dental implant planning software and to identify common sources of segmentation errors, their clinical implications, and strategies for mitigation.

Methods

This work is framed as a narrative literature review and educational practice overview. Observations on software functionality were based on direct use and exploration of varying implant planning software programs. This was conducted to qualitatively describe common segmentation error patterns (boundary errors, over-/under-segmentation, misidentification, and partial volume effects), and demonstrate editing functionalities across four implant planning systems (coDiagnostiX, BlueSkyPlan, Atomica, and Relu). These demonstrations are intended for illustrative purposes and do not constitute a formal, reproducible performance comparison.

Results

AI-based segmentation frequently encounters errors due to imaging artifacts, motion blur, anatomical variability, and algorithmic biases. These errors can lead to inaccurate implant positioning, compromised surgical guide designs, and clinical complications. While advanced methods such as U-Net, GANs, and SISTR improve segmentation quality, manual intervention remains essential. The effectiveness of AI tools varies significantly across platforms, and limited editing capabilities often hinder error correction.

Conclusion

Despite advances in AI, segmentation errors remain a critical barrier in s-CAIS workflows. Enhanced imaging protocols, algorithmic refinement, clinician oversight, and regulatory transparency are essential to improve segmentation accuracy and ensure safe, effective digital implant planning.