Clinical Implant Dentistry and Related Research最新文献

Purpose

This experiment aimed to observe the differences in biological properties by producing BGS-7 + PCL scaffolds with different weight fractions of BGS-7 through 3D printing and to confirm whether using the scaffold for vertical bone augmentation is effective.

Materials and Methods

Cube-shaped bioglass (BGS-7) and polycaprolactone (PCL) scaffolds with different weight fractions (PCL alone, PCL with 15% and 30% BGS-7) are produced using 3D printing. The surface hydroxyapatite (HA) apposition, the pH change, proliferation and attachment assays, and various gene expression levels are assessed. After a 7-mm implant was inserted 3 mm into the rabbit calvaria, vertical bone augmentation is performed around the implant and inside the scaffold in four ways: scaffold only, scaffold+bone graft, bone graft only, and no graft. Sacrifice is performed at 6, 12, and 24 weeks, and the various parameters are compared radiographically and histologically.

Results

HA apposition, cell proliferation, cell attachment, and expression of osteogenic genes increase as the proportion of BGS-7 increase. In the in vivo test, a higher bone–implant contact ratio, bone volume ratio, bone mineral density, and new bone area are observed when the scaffold and bone grafts were used together.

Conclusion

The 3D-printed scaffold, a mixture of BGS-7 and PCL, exhibit higher biological compatibility as the proportion of BGS-7 increase. Additionally, the use of scaffold is effective for vertical bone augmentation.

Purpose

To evaluate the effects of repeated abutment manipulation on the prevalence of peri-implant diseases.

Materials and Methods

A total of 27 edentulous patients (n = 108 implants) immediately restored with double-crown retained implant-supported prostheses were identified for this retrospective study. The test included the one-abutment, one-time care concept (n = 18 patients, n = 72 implants, OAOT) and the control abutment replacement (n = 9 patients, n = 36 implants, AR). A mixed effects model regression was conducted for the variable diagnosis (healthy, peri-implant mucositis, and peri-implantitis) with predictors abutment replacement (presence/absence), number of abutment replacement, category of keratinized mucosa (KM) (2 < KM ≥2 mm), and radiographic bone loss (BL).

Results

After 3–15 years (mean 10.2 ± 2.8 years), the prevalence of peri-implant mucositis and peri-implantitis in patients in the AR group was 11.1% and 88.9%, corresponding to 22.2% and 55.6% at the implant level, respectively. In OAOT group, none of the implants showed peri-implant mucositis, whereas the prevalence for peri-implantitis at patient and implant level amounted to 5.6% and 5.6%, respectively. The increased number of abutment replacements was significantly associated with the increased probability to diagnose peri-implant mucositis and peri-implantitis (OR: 6.13; 95% CI [2.61, 14.39]) (p < 0.001), whereas the presence of keratinized mucosa was not founded as a significant cofounder. The estimated mean BL in AR group was 1.38 mm larger than in OAOT group (p = 0.0190).

Conclusions

The OAOT concept was associated with a lower prevalence of peri-implant diseases.

Aim

To evaluate the efficacy of guided bone regeneration (GBR) for the treatment of peri-implant dehiscence defects using a synthetic bone substitute (SBS) or a deproteinized bovine bone mineral (DBBM) as a bone substitute.

Methods

Patients with expected dehiscence defects following implant placement were randomized to use either SBS or DBBM together with a bioabsorbable collagen membrane over dehiscenced implant surfaces aimed for GBR. The changes in the bone defect size were measured before the GBR procedure and 6 months after implant placement at the re-entry surgery. Secondary outcomes included peri-implant health outcomes, implant cumulative survival rates, bone level changes, and patient-reported outcomes (PROMs) at prosthesis delivery and 1-year follow-up.

Results

Of the 49 included patients, 24 were treated with SBS and 25 with DBBM. In the SBS group, the defect height (DH) at implant insertion was 5.1 ± 2.6 mm and was reduced at re-entry to 1.3 ± 2.0 mm (74.5%). In the DBBM group, the respective changes in DH were 4.1 ± 1.7 mm and 1.5 ± 1.9 mm (63.4%). These differences were not statistically significant (p = 0.216). The complete defect resolution rate was also comparable in both groups without statistical difference (62.5% of patients (15/24) vs. 44% of patients (11/25)). Overall, the marginal bone levels remained stable during the 1-year follow-up in both groups.

Conclusion

The SBS is noninferior to DBBM for simultaneous GBR to implant placement at implant sites with buccal dehiscences in terms of defect resolution and evaluated secondary outcomes (KCT0008393 − this clinical trial was not registered before participant recruitment and randomization).

Objectives

This retrospective study aimed to evaluate the early and late implant failure rates of one-stage lateral sinus floor elevation (LSFE) and to identify the patient and implant-related risk factors associated with these failures.

Materials and Methods

All patients treated with one-stage LSFE from January 2014 to December 2021 were evaluated for inclusion. A total of 618 patients with 936 implants met the inclusion criteria. Clinical and radiographic information about patient and implants was collected. Univariate and multivariate Cox proportional hazards frailty regression models were performed to identify risk factors for early and late implant failure.

Results

The cumulative implant survival rate was 95.62% (95% CI 93.90%–97.68%), with 16 early implant failures and 25 late implant failures. The Cox analysis indicated that ≤3 mm residual bone height (RBH) was associated with a higher early failure rate. For late implant failure, smoking habit, ≤3 mm RBH, and certain implant brand were independent risk factors. Narrow sinus ostium, long infundibulum, and flat thickening of Schneiderian membrane might be non-independent risk factors for late implant failure. No significance was found in other variables, including age, periodontitis history, implant characteristics (position, diameter, length, protrusion length, marginal bone loss), surgeon experience, healing time, opposing dentition, and prosthesis.

Conclusions

One-stage LSFE is a predictable treatment for patients with atrophic maxilla. ≤3 mm RBH increased the risk of early implant failure, while smoking habit, ≤3 mm RBH, and certain implant brand were independent risk factors for late implant failure.

Background

The cortical shell technique is frequently associated with technical drawbacks, such as the lack of anatomical guidance during shell harvest and graft. This study aims to assess the horizontal bone gain and accuracy of a digitalized protocol that incorporates two interlocking patient-specific stackable guides (PSSGs) to control the shell harvest, positioning, and fixation.

Patients and Methods

Twenty patients with deficient anterior mandibles were randomly allocated; 10 patients received freehand symphyseal shell harvest and fixation (the control group), whereas the other 10 received fully guided harvest and graft (study group) using (PSSGs), the first aided an accurate shell harvest, whereas the second conveyed shell fixation. The interposition gap among both groups was loaded with an equal mix of xenogeneic and autogenous particulates. The mean radiographic bone gain among both groups was calibrated 6 months postoperatively, and the accuracy of the digital plan was assessed by superimposing and comparing the virtually planned horizontal bone dimensions with the immediate postoperative actual bone dimensions.

Results

The mean 6-month postoperative horizontal bone gain value of the study group was recorded as (4.97 ± 0.73) mm versus (4.45 ± 0.61) mm for the control group, with a statistically insignificant mean gain difference of (0.52) mm, (p = 0.101). The mean virtual preplanned horizontal bone gain was recorded (5.4 ± 0.6) versus (5.4 ± 0.6) for the immediate postoperative actual bone gain, which was also statistically insignificant (p = 0.9).

Conclusion

The (PSSGs) provided a precise method for graft harvest, position, and fixation, resulting in satisfactory alveolar ridge dimensions with intimate accuracy.

Objectives

To investigate whether a labially inclined implant axis compromises the clinical outcomes of immediate implant placement and provisionalization (IIPP) in the anterior maxilla.

Materials and Methods

Patients with unsalvageable central or lateral maxillary incisors were enrolled. IIPP with simultaneous connective tissue graft (CTG) was performed in all participants. In the control group, the alveolar ridge had a long axis aligned with the tooth, which ensured that the immediate implant was aimed at the incisor edge or the cingulum of future restoration. The test group had a large angle between the axes of the ridge and tooth. To avoid bone fenestration, the implants were placed labially inclined and emerged from the labial side of future restoration. Intra-oral scanning and cone-beam computed tomography were performed to record soft and hard tissue profiles at baseline and 1 year later. Soft tissue stability, bone remodeling, and pink esthetic score (PES) were evaluated and compared between two groups.

Results

Thirty-nine participants (19 tests and 20 controls) completed the study. At 1-year post-surgery, the mid-facial gingival margin migrations were 0.85 ± 0.37 mm (test) and 0.81 ± 0.33 mm (control), without significant differences. No differences were identified in buccal profile alteration, linear ridge reduction, buccal bone thickness, or PES scores. The test group demonstrated thinner buccal soft tissue at the crestal level than the control group.

Conclusions

When large tooth-ridge angulation presented, labially inclined implant, avoiding buccal ridge fenestration in IIPP with CTG, did not compromise the clinical outcome in short term.

Statement of Problem

Osseointegration is now primarily established, but soft tissue integration is still susceptible to failure and problematic on implant surfaces. So, implant dentistry is increasingly focusing on improving peri-implant soft tissue integration.

Purpose

The present study aimed to evaluate the blood fibrin clot formation and adhesion on the abutment after cleaning and decontamination and determine the suitable abutment surface associated with fibrin clot attachment.

Materials and Methods

Forty-two abutments (14 per group) were used in the present study: a brand-new (BN), contaminated with biofilm (CO) and decontaminated with an enzymatic cleaner and autoclave sterilization (DEC). For a fibrin clot, 9 mL of whole human blood and abutments was centrifuged at 2700 rpm for 12 min. Clots were divided into two parts for histomorphometry and scanning electron microscopy (SEM) analysis. Twelve abutments disconnected from the clot and two not treated with blood were observed under SEM.

Results

Residual debris and biofilm were observed on the abutment surface in the CO group but not in other groups. Healthy and organized fibrin clots formed on all abutments. The fibrin extension areas are distributed uniformly in BN and DEC groups but irregularly in CO. The surface percentage of the fibrin clot extensions was 41.76% ± 6.73, 26.99% ± 6.40, and 37.83% ± 9.72 for the BN, CON, and DEC groups, respectively. The blood clot-attached areas in the CO group were statistically lower than the other groups. No difference was observed between the BN and DEC groups.

Conclusions

This study confirmed that surface contamination could influence blood clot attachment on the abutment surfaces. Cleaning and sterilization can have a favorable effect on soft tissue healing on abutment surfaces.

Background

The collaboration between otolaryngologists and dental providers is crucial for the planning and execution of maxillary sinus elevation (MSE) procedures, which are integral to successful dental implant placements.

Purpose

This article examines the essential role of otolaryngological assessments in identifying potential sinonasal risks that could impact the outcomes of MSE.

Materials and methods

A comprehensive narrative review of existing literature was conducted.

Discussion

The review underscores the importance of thorough preoperative evaluations, including patient history, computed tomography (CT) or cone-beam CT (CBCT) scans, and nasal endoscopy, to mitigate sinonasal health risks. It details various clinical scenarios and patient assessments, emphasizing a systematic approach to diagnosing and managing sinonasal conditions proactively. The discussion reveals that while some sinus conditions may not significantly affect MSE success, conditions impacting mucociliary clearance and sinus drainage are critical risk factors requiring otolaryngological intervention. Additionally, the article introduces a grading system to assist clinicians in identifying patients who would benefit from otolaryngological evaluations prior to MSE.

Conclusion

This review highlights the value of interdisciplinary collaboration and standardized protocols in enhancing the predictability and safety of MSE procedures, ultimately improving patient outcomes.

Purpose

This multicenter cross-sectional clinical study aimed to evaluate the membrane perforation rate during transcrestal sinus floor elevation (TSFE) using osseodensification (OD) burs and assess risk factors associated with the procedure.

Materials and Methods

This study was conducted in six centers, following ethical standards and approved by local committees. It included patients over 18 years old missing maxillary posterior teeth with crestal residual bone height (RBH) ≥2 and ≤6 mm. Preoperative evaluations were done, including CBCT scans, to assess bone dimensions and sinus health. All centers and surgeons followed a standardized surgical protocol for TSFE using OD burs. Surgical complications, particularly sinus membrane perforations, were recorded and analyzed. Factors such as implant site, premolars or molars, as well as, healed or fresh socket, along with initial RBH were evaluated for their impact on membrane perforation rate. Descriptive statistics, χ², and logistic regression analysis were used to analyze the data.

Results

A total of 621 subjects with an average age of 57.9 years were included. Sinus lifting was performed at 670 sites, with 621 implants placed in the maxilla. The majority of sinus lifts were done in the molar region (76.87%) and in healed bone sites (74.33%). The average RBH was 5.1 mm (ranging from 2 to 7 mm). Sinus membrane perforation occurred in 49 cases (7.31%). RBH ≤3 mm posed a risk factor for sinus membrane perforations followed by RBH >3 and ≤5 mm. Tooth region and implant site were not associated as risk factors for sinus membrane perforation.

Conclusion

OD drilling used for TSFE resulted in low membrane perforation rate. Challenging scenarios of severe posterior maxillary atrophy presented as risk factors for increased perforation rate.

Background

Robot-assisted implant surgery has emerged as a novel digital technology, and the accuracy need further assessment.

Purpose

This study aimed to compare the accuracy of single dental implant placement between a novel semi-active robot-assisted implant surgery (RAIS) method and the conventional free-hand implant surgery (FHIS) method through a multicenter, randomized controlled clinical trial.

Materials and Methods

Patients requiring single dental implant placement were recruited and randomized into RAIS and FHIS group. Deviations at the platform, apex, and angle between the planned and final implant positions were assessed in both groups. Additionally, the evaluation of instrument and surgical complications was examined.

Results

A total of 140 patients (median age: 35.35 ± 12.55 years; 43 males, 97 females) with 140 implants from four different research centers were included, with 70 patients (70 implants) in the RAIS group and 70 patients (70 implants) in the FHIS group. In the RAIS and FHIS groups, the median platform deviations were 0.76 ± 0.36 mm and 1.48 ± 0.93 mm, respectively (p < 0.001); median apex deviations were 0.85 ± 0.48 mm and 2.14 ± 1.25 mm, respectively (p < 0.001); and median angular deviations were 2.05 ± 1.33° and 7.36 ± 4.67°, respectively (p < 0.001). Similar significant difference also presented between RAIS and FHIS group in platform vertical/horizontal deviation, apex vertical/horizontal deviation. Additionally, implants with self-tapping characteristics exhibited significantly larger deviations compared with those without self-tapping characteristics in the RAIS group. Both RAIS and FHIS methods demonstrated comparable morbidity and safety pre- and post-operation.

Conclusions

The results indicated that the RAIS method demonstrated superior accuracy in single dental implant placement compared with the FHIS method. Specifically, RAIS exhibited significantly smaller deviations in platform, apex, and angular positions, as well as platform and apex vertical/horizontal deviations.

This clinical trial was not registered prior to participant recruitment and randomization. https://www.chictr.org.cn/showproj.html?proj=195045.