Clinical Implant Dentistry and Related Research最新文献

Aim

To investigate whether the lack of keratinized mucosa (KM) affects peri-implant health after 10 years of loading.

Materials and Methods

Data from 74 patients with 148 implants from two randomized controlled studies comparing different implant systems were included and analyzed. Clinical parameters including bleeding on probing (BOP), probing depth (PD), plaque index, marginal bone loss (MBL), and KM width (KMW) at buccal sites were collected at baseline (time of the final prosthesis insertion), 5-year and 10 years postloading. Multivariable logistic and linear regression models by means of a generalized estimated equation (GEE) were used to evaluate the influence of buccal KM on peri-implant clinical parameters; BOP, MBL, PD, and adjusted for implant type (one-piece or two-piece) and compliance.

Results

A total of 35 (24.8%) implants were healthy, 67 (47.5%) had mucositis and 39 (27.6%) were affected by peri-implantitis. In absence of buccal KM (KM = 0 mm), 75% of the implants exhibited mucositis, while in the presence of KM (KMW >0 mm) 41.2% exhibited mucositis. Regarding peri-implantitis, the corresponding percentages were 20% (KM = 0 mm) and 26.7% (KM >0 mm). Unadjusted logistic regression showed that the presence of buccal KM tended to reduce the odds of showing BOP at buccal sites (OR: 0.28 [95% CI, 0.07 to 1.09], p = 0.06). The adjusted logistic regression model revealed that having buccal KM (OR: 0.21 [95% CI, 0.05 to 0.85], p = 0.02) and using two-piece implants (OR: 0.34 [95% CI, 0.15 to 0.75], p = 0.008) significantly reduced the odds of showing BOP. Adjusted linear regression by means of GEE showed that KM and two-piece implants were associated with reduced MBL and MBL changes (p < 0.05).

Conclusion

The lack of buccal KM appears to be linked with peri-implant parameters such as BOP and MBL, but the association is weak. The design of one-piece implants may account for their increased odds of exhibiting BOP.

Background

Immediate implant restoration by prefabricated prosthesis has multiple benefits. However, the design and insertion workflow of the prosthesis may influence the seating.

Purpose

Evaluation of seating accuracy of prefabricated interim prosthesis of different designs and insertion workflows for immediate restoration of implants placed via static computer-assisted implant surgery (sCAIS).

Materials and Methods

A maxillary model without incisors was used to plan for two implants at the lateral incisor locations. According to the planned implants, sCAIS surgical template and a four-unit interim prosthesis were designed. Four prostheses were fabricated based on the design and insertion workflow. The first prosthesis involved complete fabrication (CF) of the interim prosthesis, where the interim prosthesis is fabricated for laboratory attachment to abutments. The other three prostheses were produced by partial fabrication (PF), where the interim prosthesis shell was produced with internal spacing between the fitting surface and the abutments. The PF prostheses were cemented on abutments attached to the inserted implants. Three different PF prosthesis designs were included with different levels of internal spacing: 100 μm (PF.1), 200 μm (PF.2), and 300 μm (PF.3). A total of 15 surgical models received implants on which each prosthesis was seated and scanned by a laboratory scanner. The vertical, horizontal, and proximal contact errors were measured.

Results

Although all prostheses were seated on every model, the CF prostheses had greater vertical error, followed by PF.1, PF.2, and PF.3 prostheses, respectively. A similar pattern was observed for proximal contact error, where PF.3 was most superior. PF.3 prostheses had the least horizontal error than the other prostheses.

Conclusions

All interim prostheses experienced errors at the vertical, horizontal, and proximal surfaces, which can be attributed to deviations of the inserted implants. The PF of interim prosthesis with increased internal spacing for intraoral insertion appeared to reduce seating errors.

Aims

(1) To assess the effectiveness of the Sausage Technique™ when applied for lateral bone augmentation by multiple experienced clinicians; (2) To identify risk indicators for a poor outcome and to assess the need for adjunctive surgery.

Materials and Methods

All patients who had been treated with the Sausage Technique™ for lateral bone augmentation by three experienced surgeons between January 2019 and December 2021 were included in a retrospective case series. The Sausage Technique™ technique includes the use of autogenous bone chips and deproteinized bovine bone mineral (1:1 ratio), covered with a stretched and pinned collagen membrane. The increase in alveolar width between the pre-operative situation and 9 months was assessed at different levels on superimposed cone-beam CT scans.

Results

Twenty-five augmentations performed in 25 patients (17 males, 8 females, mean age 51 years) were available for evaluation. Mean alveolar width increased from 4.35 to 7.43 mm at 3 mm below the crest. The mean increase of 3.08 mm (95% CI 2.10–4.06; p < 0.001) was significant. The outcome of non-containing single implant sites was significantly worse than the outcome of other sites (MD 2.67 mm; p = 0.008). The need for regrafting was 4% and the need for soft tissue augmentation was 48%. Twenty percent of the patients needed soft tissue augmentation due to a lack of keratinized mucosa width, and 32% due to a lack of buccal convexity. The former was mainly needed at multiple implant sites, whereas the latter was mainly required at single implant sites. All implant survived and remained healthy until the final follow-up.

Conclusion

The Sausage Technique™ is an effective bone augmentation technique. Non-containing single implant sites were associated with a poor outcome and adjunctive soft tissue augmentation was needed in about half of the patients.

Objectives

The current guidelines recommend that immediate implants be placed in patients with thick (>1 mm) buccal bone due to the inevitable tissue remodeling that follows tooth extraction. The aim of the current study was to investigate the effect of buccal bone thickness on bone resorption in immediate implant placement and compare two measuring techniques of the aforementioned resorption.

Materials

The present study was designed as a prospective nonrandomized, controlled clinical trial. A total of 30 implants were split between the two study arms, thin buccal bone and thick buccal bone. The primary outcome was to assess vertical bone changes radiographically by cone beam scans preoperatively, at 2 months and 18 months after implant placement in patients with thin and thick buccal plate. Secondary outcomes included the change in the thickness of the buccal bony plate, marginal bone loss, and pink esthetic score.

Results

Only 26 implants were statistically analyzed as one early failure was observed in each group. Furthermore, 2 patients of the thick group withdrew from the study. Cone beam computed tomography measurements revealed that at 2 months the vertical bone loss was 1.09 for the thin group and 0.85 for the thick group. The buccal bone plate resorption of the thin group was 0.39 mm while it was 0.52 mm for the thick group. The buccal bone plate was 1.25 mm in the thin group and 1.88 mm in the thick group. The PES did not show any significant difference with very good esthetic results.

Conclusion

Within the limitations of the current study, the amount of buccal bone plate resorption and the subsequent thickness obtained after implantation in both groups suggest successful long-term results. The two measuring techniques have proven to be comparable and reliable in the measurement of buccal bony plate changes.

https://classic.clinicaltrials.gov/ct2/results?cond=&term=NCT04731545&cntry=EG&state=&city=&dist=

Purpose

This retrospective study evaluated the effect of selected clinical and patient factors on survival, success, and peri-implant bone level changes of locking taper implants supporting molar crowns on Bicon's prefabricated shouldered abutments.

Methods

A total of 234 patients, who received 274 single molar crowns supported by locking taper implants were included in this retrospective study. Kaplan–Meier survival analysis was used to assess overall implant survival, prostheses survival, and success. Crowns were either monolithic (resin based) or bilayered (milled fiber-reinforced composite coping veneered with indirect composite). Early and late changes in marginal bone levels were plotted and analyzed with equivalence testing to compare the effects of different factors on crestal bone levels.

Results

At 9.5 years after implant surgery, the implant survival probability was 94.2%, the probability of prosthesis survival was 91.4%, and the probability of prosthetic success was 90.4%. Neither the use of different crown materials, nor the choice of monolithic versus bilayered crown construction, significantly affected the probability of prosthetic success. Marginal bone levels, on average, trended downwards towards the top of the implant within the first 2 years after functional loading, and remained stable on average, since then. Factors affecting bone levels included the use of nonsteroidal anti-inflammatory drugs, which precluded early implant bone loss; and subcrestal implant placement, which was linked to significantly higher long-term bone levels.

Conclusion

The implant and abutment system studied resulted in high implant and prosthetic survival rates, regardless of prosthetic material used, with stable bone levels over time.

Background

A peri-implant cystic lesion is a rare finding, and to date most investigators have considered that its pathogenesis is caused by trauma and infection related to dental implantation. However, the pathogenesis of these cysts remains unclear and is recognized to have multifactorial origins.

Case presentation

In February 2021, a 75-year-old male patient underwent implant restoration due to mobility of the left maxillary central incisor. The implant achieved good osseointegration and was successfully restored. However, in March 2023, the patient sought treatment due to mobility of the dental implant. Clinical examination showed that the implant had loosened in three directions (vertical, mesial-distal, and labial-lingual), and the peri-implant mucosa was slightly red and swollen. Radiographic examination (cone beam computed tomography) showed a large radiolucent area with clear boundaries involving the cervical and middle portions of the dental implant, and white bone lines were observed at the edge of the low-density shadow. Intraoperatively, we removed the patient's implant, performed a complete debridement, and conducted bone augmentation surgery in the area of bone defect. Postoperatively, the patient recovered well. The final histopathological result confirmed an epidermoid cyst.

Conclusions

Peri-implant epidermoid cyst is a rare complication that affects the long-term outcome of implant therapy. This case serves as a warning to clinicians to avoid involving epithelial tissue in the implant site during implant surgery, in order to prevent the potential occurrence of a peri-implant epidermoid cyst, thereby creating better conditions for the patient's recovery and the long-term efficacy of the implant.

Aim

This case series aimed to evaluate the effectiveness of the autologous circular cortical lamina-anchoring (CCA) technique for horizontal bone augmentation in the maxillary aesthetic region.

Materials and methods

A total of 25 patients with 28 implants underwent horizontal bone augmentation using CCA followed by implant placement and crown delivery. The primary outcome measures were alveolar ridge width (ARW) and buccal bone thickness (BBT), whereas the secondary outcome measures included marginal bone loss (MBL), mid-facial mucosal margin loss (MML), clinical assessment of peri-implant and aesthetic parameters, patient-reported outcome measures (PROMs), and implant survival rates.

Results

All 25 patients with 28 implants completed the treatment, no dropouts occurred. After CCA, the mean ARW at 1, 2, and 4 mm below the alveolar crest significantly increased from 2.38 ± 0.48, 2.85 ± 0.51, and 3.21 ± 0.53 mm to 6.80 ± 0.48, 6.99 ± 0.50, and 8.08 ± 0.52 mm, respectively. At the 3-year follow-up, the mean BBT₀, BBT₂, and BBT₄ slightly decreased from 2.51 ± 0.26, 2.63 ± 0.31, and 2.75 ± 0.29 mm to 2.43 ± 0.27, 2.51 ± 0.30, and 2.64 ± 0.28 mm, respectively. Although the overall MBL was <0.15 mm, the results were statistically significant. The mean MML at the 3-year follow-up was 0.02 mm. All implant sites showed acceptable peri-implant and aesthetic outcomes. Incisions healed without complications, and no significant differences in PROMs observed at any time point. The 3-year follow-up showed a 100% implant survival rate.

Conclusion

The autologous CCA technique is a useful method for increasing ARW and maintaining BBT in the maxillary aesthetic region.

Aims

The aim of this randomized controlled clinical trial was to compare the gene expression, micro-CT, histomorphometrical analysis between biphasic calcium phosphate (BCP) of 70/30 ratio and deproteinized bovine bone mineral (DBBM) in sinus augmentation.

Materials and Methods

Twenty-four patients in need for sinus floor augmentation through lateral approach were randomized into BCP 70/30 ratio or DBBM. After at least 6 months of healing, a total of 24 bone specimens were collected from the entire height of the augmented bone at the area of implant placement and underwent micro-CT, histomorphometric and gene expression analysis. The 12 bone specimens of BCP 70/30 ratio were equally allocated to micro-CT and histologic analysis (test group, n = 6) and gene expression analysis (test group, n = 6). Similarly, the 12 bone specimens of DBBM were also allocated to micro-CT and histologic analysis (control group, n = 6) and gene expression analysis (control group, n = 6). The newly formed bone, remaining graft materials and relative change in gene expression of four target genes were assessed.

Results

The micro-CT results showed no statistically significant difference in the ratio of bone volume to total volume (BV/TV ratio) for the two groups (BCP 41.51% vs. DBBM 40.97%) and the same was true for residual graft material to total volume (GV/TV ratio, BCP 9.97% vs. DBBM 14.41%). Similarly, no significant difference was shown in the histological analysis in terms of bone formation, (BCP 31.43% vs. DBBM was 30.09%) and residual graft area (DBBM 40.76% vs. BCP 45.06%). With regards to gene expression, the level of ALP was lower in both groups of bone grafted specimens compared with the native bone. On the contrary, the level of OSX, IL-1B and TRAP was higher in augmented bone of both groups compared with the native bone. However, the relative difference in all gene expressions between BCP and DBBM group was not significant.

Conclusions

The BCP, HA/β-TCP ratio of 70/30 presented similar histological and micro-CT outcomes in terms of new bone formation and residual graft particles with DBBM. The gene expression analysis revealed different gene expression patterns between augmented and native bone, but showed no significant difference between the two biomaterials.

Introduction

To evaluate the adjunctive effect of glycine-powder air-polishing (GPAP) to full-mouth ultrasonic debridement (Fm-UD) in the treatment of peri-implant mucositis, and to determine the impact of implant and patient-level variables for disease resolution.

Methods

Individuals with a diagnosis of peri-implant mucositis were consecutively included in this randomized parallel arm clinical study. All the participants received a session of Fm-UD. Only implants allocated to the test group were additionally treated with GPAP. Clinical assessments were recorded at baseline, at 3 and at 12 months following intervention. The primary outcomes were complete disease resolution (DR1), defined as absence of bleeding sites at probing per implants, and partial disease resolution (DR2), measured as the presence of less than two bleeding sites at probing per implant. A final logistic multivariate regression model was built to evaluate the predictive role of implant and patient-level variables on DR.

Results

Fifty two patients and 157 implants were included. Both groups displayed significant reduction in the extent of bleeding on probing and plaque levels. At 12 months, DR1 was achieved in 16% and 27% of participants for the test and the control group respectively. IDR1 was best predicted by the number of bleeding sites (OR = 2.7, p = 0.04) and the greatest PPD value (OR = 2.7, p = 0.05), while IDR2 by the prosthetic connection (OR = 2.59, p = 0.02), the mean PPD (OR = 2.23, p = 0.04), the FMBS (OR = 4.09, p = 0.04), and number of implants (OR = 4.59, p = 0.02).

Conclusions

Despite significant improvements of clinical signs of peri-implant inflammation, the use of GPAP appears to have no adjunctive effect as compared with Fm-UD alone in the achievement of DR. Elevated initial levels of bleeding and PD predicted inferior likelihood of reaching disease resolution. The present randomized parallel arm clinical study was registered on Clinicaltrials.gov and received the following registration number: NCT05801315. This clinical trial was not registered prior to participant recruitment and randomization (https://register.clinicaltrials.gov/prs/app/action/SelectProtocol?sid=S0009965&selectaction=Edit&uid=U0004FXM&ts=2&cx=fje7l8).