Clinical Implant Dentistry and Related Research最新文献

Introduction

Crestal bone level (CBL) changes following implant placement may result from both physiological and pathological processes. Although early marginal bone remodeling is generally regarded as a physiological response, its progression must be carefully monitored. Identifying long-term risk factors is essential for preserving peri-implant bone stability. This study aims to assess changes in CBL and crestal bone remodeling (CBR) over a 4-year period in periodontally healthy patients undergoing regular supportive care.

Materials and Methods

This retrospective study included 97 patients with a total of 142 implants who received implant-supported restorations and consistently attended supportive maintenance therapy. Patients with a history of periodontitis were excluded. Radiographic evaluation was conducted at four time points: T0 (implant placement), T1 (prosthetic loading), T2 (1 year after loading), and T3 (4 years after loading). CBL and CBR were assessed using calibrated digital measurements. The effects of systemic, surgical, site-related, and prosthetic variables on CBL and CBR were analyzed using linear regression and Pearson correlation tests.

Results

Smoking was the only consistent predictor of increased CBL loss across all intervals (p < 0.001). In the early phases (T1–T0, T2–T1), subcrestal placement was associated with significantly less bone loss (p ≤ 0.003). In the late phase (T3–T2), implant diameter became a significant predictor (p = 0.002). Prosthetic factors were not significant in the overall analysis. However, within the subcrestal subgroup, screw-retained prostheses, platform-switched connections, and anterior placement were associated with reduced CBR during specific intervals. Strong correlations were observed between CBL changes across all intervals, indicating progressive and cumulative bone dynamics.

Conclusion

The primary factor for initial bone stability is the depth of implant placement, whereas long-term results are mainly affected by implant geometry and prosthetic design. Smoking continues to be a significant, modifiable risk factor. These insights emphasize the importance of individualized treatment plans and maintenance strategies to ensure long-term implant success.

Introduction

Dental implants are widely utilized to manage both partially and completely edentulous older patients. However, such patients often present with multiple systemic diseases and may be at an increased risk of complications before and after implant surgery. Nevertheless, population-level data on systemic diseases and medication use in these patients remain limited.

Methods

This retrospective, cross-sectional study analyzed 36 957 patients who underwent 43 171 insurance-covered implant surgeries between 2014 and 2019 using the National Health Insurance Service-National Sample Cohort (NHIS-NSC) database. Patients aged 65 years or older were included. Sociodemographic characteristics, diagnosis of systemic diseases within 1 year before implant surgery, medication history, and type of medical institution were evaluated. Additionally, logistic regression analysis was performed to investigate factors associated with implant removal.

Results

Among 36 957 patients who underwent 43 171 implant surgeries, implant removal occurred in 803 patients. Within 1 year before surgery, 89.33% had at least one systemic disease, including hypertension (57.92%), arthritis (43.39%), and diabetes (34.62%). Antithrombotic and antiresorptive agents were prescribed to 6.77% and 5.05% of patients, respectively. The use of intravenous (IV) bisphosphonates, denosumab, and direct oral anticoagulants (DOACs) increased, whereas the use of oral bisphosphonates and warfarin decreased. Logistic regression analysis showed that cerebrovascular and kidney disease increased the risk of implant removal, whereas osteoporosis and antiresorptive agents decreased the risk.

Conclusion

Most older patients who underwent implant surgery had systemic diseases, and approximately 10% were prescribed medications. Cerebrovascular and kidney diseases increased the risk of implant removal, whereas osteoporosis or antiresorptive therapy decreased the risk. With the increasing use of DOACs, IV bisphosphonates, and denosumab, clinicians carefully review the medical histories of older implant patients.

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.