Clinical outcomes of implant- versus abutment-level connection in screw-retained fixed dental prostheses: A 5-year randomized controlled trial.

AIM: The aim of the study was to evaluate the 5 years clinical outcomes associated with implant-level connection (IL) versus abutment-level connection (AL) for implants with an internal conical connection (ICC) supporting a screw-retained fixed partial denture. MATERIALS AND METHODS: Fifty patients with 119 implants were randomly allocated to either the AL or IL group. Radiographic (Marginal bone loss) and clinical outcomes (Bleeding on Probing, probing pocket depth, plaque accumulation, incidence of peri-implantitis and peri-implant mucositis as well as prosthetic complications) were collected and compared at 1, 2, 3, and 5 years. A linear mixed model was used to evaluate the differences between groups. RESULTS: Five years after treatment, the MBL change was not significantly different between the groups at any point. The MBL was 0.23 ± 0.64 mm (AL) and 0.23 ± 0.29 mm (IL). The bleeding on Probing was 44% (AL) and 45% (IL) (p = .89). The mean probing depth was 2.91 ± 1.01 mm (AL) and 3.51 ± 0.67 mm (IL). This difference between the groups was statistically significant but clinical insignificant. Presence of plaque was slightly higher (p = .06) in the IL group (34.4%) compared with the AL group (26.3%). The overall technical, biological, and prosthetic complication rates were similar between groups. None of the implants developed peri-implantitis during the entire follow-up period. CONCLUSION: The results of this clinical trial indicated that all clinical and radiographical parameters were clinically comparable between the study groups.

Periodontal risk score: Initiation and model validation for 6,762 teeth.

BACKGROUND: Tooth-level prognostic systems are valuable tools for treatment planning and risk assessment of periodontally involved teeth. Recently the Miller-McEntire prognosis index was found to outperform comparable systems. However, it had some limitations. The present study aimed to develop and evaluate the prognostic performance of a modified version that addresses most limitations of the previous model called the periodontal risk score (PRS). METHODS: Data were retrieved retrospectively from patients who received surgical and non-surgical periodontal treatment at a university setting. Data on medical history and smoking status at baseline and the last maintenance visit were collected. Both univariate and multivariate Cox proportional hazard regression models were used to analyze the prognostic capability for predicting tooth loss due to periodontitis (TLP) risk. RESULTS: A total of 6762 teeth (281 patients) were followed up for a mean period of 22.6 ± 6.34 (10-47.6y) years. The PRS was successfully able to stratify the risk of TLP at baseline when the three different classes of association were compared for anterior and/or posterior tooth loss. After controlling for maintenance, age, and sex, the index showed an excellent predictive capacity for TLP with a Harrell C-index of 0.947. CONCLUSIONS: The periodontal risk score (PRS) displayed excellent predictive capability for anterior as well as posterior tooth loss due to periodontitis. This system was able to predict long-term tooth loss with a very high accuracy  in a population treated mainly by dental students and periodontics residents. The use of this/similar prognosis system is advisable as a means to establish tooth prognosis.

Surgery start time and early implant failure: A case-control study.

OBJECTIVE: To evaluate the influence of surgery start time (SST) and other patient- and therapy-related variables on the risk for early implant failure (EIF) in an academic setting. MATERIAL AND METHODS: Data were extracted from the electronic health records of 61 patients who had at least one EIF and 140 age- and gender-matched, randomly selected, non-EIF controls. Bivariate and multivariable analyses were performed to identify relevant associations between EIF and different variables, such as SST. RESULTS: Incidence of EIF was not significantly associated with SST (HR: 1.9 for afternoon implant placement, 95% CI: 0.9-3.9; p = .105). Other factors that were associated with a significantly increased risk for EIF in a multivariable model were pre-placement ridge augmentation (HR: 7.5, 95% CI: 2.2-25.1; p = .001), intra-operative complications (HR: 5.9, 95% CI: 2.2-16.3; p < .001), simultaneous soft tissue grafting (HR: 5.03, 95% CI: 1.3-19.5; p = .020), simultaneous bone grafting (HR: 3.7, 95% CI: 1.6-8.8; p = .002), and placement with sedation (HR: 3.4, 95% CI: 1.5-7.5; p = .002). CONCLUSIONS: While SST was not associated with the occurrence of EIF in our cohort, other variables, such as ridge augmentation prior to implant placement, simultaneous bone or soft tissue grafting, intra-operative complications, implant placement with sedation, and number of implants in the oral cavity, were associated with an increased risk for this adverse event.

Static computer-aided, partially guided, and free-handed implant placement: A systematic review and meta-analysis of randomized controlled trials.

OBJECTIVE: To analyze the outcomes of static computer-aided implant placement (sCAIP) compared to partially guided (PGIP) and free-handed (FHIP) implant placement. MATERIAL AND METHODS: This study was registered in PROSPERO (CRD42019131397). A comprehensive literature search was performed by two independent examiners. Only randomized controlled trials (RCTs) were selected. Treatment modalities included sCAIP, PGIP, and FHIP. Data pertaining to the outcomes of interest were extracted. Random-effects meta-analyses were feasible for a subset of outcomes. RESULTS: From an initial list of 2,870 records, fourteen articles for a total of ten RCTs were selected. Data from 7 of these studies allowed for the conduction of three meta-analyses comparing accuracy of implant placement across modalities. Survival rate up to 12 months post-loading was high (>98%) and comparable between treatments (low-quality evidence). No tangible differences in terms of patient perception of intra- or postoperative discomfort were observed (low-quality evidence). Quantitative analyses revealed significantly lower angular (MD = 4.41°, 95% CI 3.99-4.83, p < .00001), coronal (MD = 0.65 mm, 95% CI 0.50-0.79, p < .00001), and apical (MD = 1.13 mm, 95% CI 0.92-1.34, p < .00001) deviation values for sCAIP as compared to FHIP (8 studies, 383 patients, 878 implants, high-quality evidence). A similar discrepancy, in favor of sCAIP, was observed for angular deviation only as compared to PGIP (MD = 2.11°, 95% CI 1.06-3.16, p < .00001). CONCLUSIONS: sCAIP is associated with superior accuracy compared to PGIP and FHIP.

Ultrasonography for chairside evaluation of periodontal structures: A pilot study.

BACKGROUND: The crestal bone level and soft tissue dimension are essential for periodontal diagnosis and phenotype determination; yet, existing measurement methods have limitations. The aim of this clinical study was to evaluate the correlation and accuracy of ultrasound in measuring periodontal dimensions, compared to direct clinical and cone-beam computed tomography (CBCT) methods. METHODS: A 24-MHz ultrasound probe prototype, specifically designed for intraoral use, was employed. Periodontal soft tissue dimensions and crestal bone levels were measured at 40 teeth and 20 single missing tooth gaps from 20 patients scheduled to receive a dental implant surgery. The ultrasound images were interpreted by two calibrated examiners. Inter-rater agreement was calculated by using inter-rater correlation coefficient (ICC). Ultrasound readings were compared with direct clinical and CBCT readings by using ICC and Bland-Altman analysis. RESULTS: The following six parameters were measured: 1) interdental papilla height (tooth), 2) mid-facial soft tissue height (tooth), 3) mucosal thickness (tooth), 4) soft tissue height (edentulous ridge), 5) mucosal thickness (edentulous ridge), and 6) crestal bone level (tooth). Intra-examiner calibrations were exercised to achieve an agreement of at least 0.8. ICC between the two readers ranged from 0.482 to 0.881. ICC between ultrasound and direct readings ranged from 0.667 to 0.957. The mean difference in mucosal thickness (tooth) between the ultrasound and direct readings was -0.015 mm (95% CI: -0.655 to 0.624 mm) without statistical significance. ICC between ultrasound and CBCT ranged from 0.654 to 0.849 among the measured parameters. The mean differences between ultrasound and CBCT range from -0.213 to 0.455 mm, without statistical significance. CONCLUSION: Ultrasonic imaging can be valuable for accurate and real-time periodontal diagnosis without concerns about ionizing radiation.

Comparison between Subepithelial Connective Tissue Graft and De-epithelialized Gingival Graft: A systematic review and a meta-analysis.

AIM: Sup-epithelial connective tissue graft (SCTG) and de-epithelialized gingival graft (DGG) approaches have been investigated with a focus on post-operative morbidity but not from a clinical outcome standpoint. The aim of this systematic review was to systematically investigate the literature for coronally advanced flaps (CAFs) combined with SCTG or DGG. MATERIALS AND METHODS: Electronic and hand searches were performed to identified randomized controlled trials (RCTs) investigating the treatment of gingival recession (GRs) using CAF, with at least a 1-year of follow-up. The primary outcome was the mean root coverage (mRC), while the secondary outcomes included recession reduction (Rec Red), keratinized tissue (KT) gain, probing depth (PD) change, and clinical attachment level (CAL) gain. RESULTS: Ten RCTs with a total of 408 gingival recessions were included. The meta-analysis demonstrated that CAF + DGG is associated with superior mRC, Rec Red, KT gain, PD reduction and CAL gain. The mRC for SCTG and DGG at 1-year was 89.3% and 94.0% respectively, while the mean difference of the other clinical parameters between the two approaches was within 1 mm in favor of the DGG group. CONCLUSIONS: Limited evidence is available when comparing the two techniques, however the usage of DGG may be considered as the preferred technique of choice for autologous CTG harvesting when incorporated with a CAF.

Incidence and severity of postoperative complications following oral, periodontal, and implant surgeries: A retrospective study.

BACKGROUND: Incidence and severity of postoperative complications are key elements in determining the risk-benefit relationship of any surgical procedure. The aim of this retrospective study was to assess and categorize the postoperative complications that occur following, and are associated with, oral, periodontal, and implant surgeries. METHODS: A total of 3,900 patients who underwent surgical procedures including, but not limited to, sinus floor elevation, guided tissue regeneration, crown lengthening, implant placement, soft tissue graft, open flap debridement or surgical removal of impacted teeth were included. Postoperative complications were recorded and graded based on impedance to routine daily activity and favorable surgical outcomes. Regression models were generated to evaluate correlations between complication types, as well as between patient/surgical characteristics and the incidence of complications. RESULTS: Surgical removal of impacted teeth and lateral sinus floor elevation had the highest incidence and severity of complications. Postoperative dentinal hypersensitivity (5.7%) was the most frequent complication, followed by excessive pain (4.1%), and moderate postoperative bleeding (3.5%). Based on the devised grading system described in this paper, the complications were 11.1% of Grade I, 3.3% of Grade II, 8.3% of Grade III, 0.1% of Grade IV, and no complications recorded under Grades V or VI. CONCLUSIONS: Surgical removal of impacted teeth and lateral sinus floor elevation are more prone to more severe complications compared with other procedures. Additionally, complications that do not impede favorable surgical outcomes and/or routine daily activity are the most likely to occur. Smoking and diabetes are generally associated with postoperative complications.

Schneiderian membrane perforation via transcrestal sinus floor elevation: A randomized ex vivo study with endoscopic validation.

OBJECTIVE: To endoscopically determine the incidence of Schneiderian membrane perforation during transcrestal maxillary sinus floor elevation (SFE), in relation to the bone preparation technique, amount of bone graft, membrane elevation height and different surgical steps. MATERIALS AND METHODS: Seven cadaver heads corresponding to 12 maxillary sinuses were used to perform three SFE via transcrestal approach per sinus (36 elevations). Each sinus was randomly assigned to either the Sinus Crestal Approach (SCA) drill kit technique (experimental group) or the conventional osteotome technique (control group). During all phases of the surgery, the integrity of the sinus membrane was monitored through endoscopic examination. RESULTS: A significant difference was found in the incidence of perforation (p = 0.007) and vertical elevation height (p < 0.001) between the study groups, favoring the experimental group. A safety elevation threshold of 5 mm without bone graft and implant placement was estimated. A significant correlation was observed between the residual ridge height and the incidence of perforation (p < 0.001; OR = 0.51). CONCLUSION: The SCA drill kit may demonstrate superior osteotomy preparation and membrane elevation capabilities to the osteotome technique, and significantly when a 6-mm SFE is indicated. Residual ridge height and vertical elevation height are risk determinant factors.

Clinical outcomes and cost effectiveness of computer-guided versus conventional implant-retained hybrid prostheses: A long-term retrospective analysis of treatment protocols.

BACKGROUND: Computer-guided systems were developed to facilitate implant placement at optimal positions in relation to the future prosthesis. However, the time, cost and, technique sensitivity involved with computer-guided surgery impedes its routine practice. The aim of this study is to evaluate survival rates and complications associated with computer-guided versus conventional implant placement in implant-retained hybrid prostheses. Furthermore, long-term economic efficiency of this approach was assessed. METHODS: Patients were stratified according to implant placement protocol into a test group, using computer-guided placement, and a control group, using traditional placement. Calibrated radiographs were used to measure bone loss around implants. Furthermore, the costs of the initial treatment and prosthetic complications, if any, were standardized and analyzed. RESULTS: Forty-five patients (149 implants in the test group and 111 implants in the control group) with a minimum follow-up of 5 years, and a mean follow-up of 9.6 years, were included in the study. While no significant difference was found between both groups in terms of biologic and technical complications, lower incidence of implant loss was observed in the test group (P < 0.001). A statistically significant difference in favor of the non-guided implant placement group was found for the initial cost (P < 0.05) but not for the prosthetic complications and total cost (P > 0.05). CONCLUSIONS: Computer-guided implant placement for an implant-supported hybrid prosthesis is a valid, reliable alternative to the traditional approach for implant placement and immediate loading. Computer-guided implant placement showed higher implant survival rates and comparable long-term cost to non-guided implant placement.