Impact of surface chemical treatment in surgical regenerative treatment of ligature-induced peri-implantitis: A canine study.

BACKGROUND: Implant surface decontamination is a critical step in peri-implantitis treatment. The aim of this study was to assess the effect chemotherapeutic agents have on reosseointegration after treatment on ligature-inducted peri-implantitis. METHODS: Six male canines had 36 implants placed and ligatures were placed around them for 28 weeks to establish peri-implantitis. The peri-implant defects were randomly treated by 1 of 3 methods: 0.12% chlorhexidine (CHX test group), 1.5% sodium hypochlorite (NaOCl test group), or saline (Control group). Sites treated with NaOCl and CHX were grafted with autogenous bone, and all sites then either received a collagen membrane or not. Histology sections were obtained at 6 months postsurgery to assess percentage of reosseointegration. RESULTS: Thirty-five implants were analyzed (CHX: 13; NaOCl: 14; Control:8). NaOCl-treated sites demonstrated reosseointegration with direct bone-to-implant-contact on the previously contaminated surfaces (42% mean reosseointegration), which was significantly higher than Controls (p < 0.05). Correspondingly, clinical improvement was noted with a significant reduction in probing depth from 5.50 ± 1.24 mm at baseline to 4.46 ± 1.70 mm at 6-months postsurgery (p = 0.006). CHX-treated sites demonstrated a nonsignificant reosseointegration of 26% (p > 0.05); however, in the majority of cases, the new bone growth was at a distance from the implant surface without contact. Probing depths did not improve in the CHX group. The use of membrane did not influence reosseointegration or probing depths (all p > 0.05). CONCLUSION: Titanium implants with peri-implantitis have the capacity to reosseointegrate following regenerative surgery. However, treatment response is contingent upon the chemotherapeutic agent selection. Additional chemical treatment with 1.5% NaOCl lead to the most favorable results in terms of changes in defect depth and percentage of reosseointegration as compared to CHX, which may hinder reosseointegration.

Accuracy of robotic surgery for dental implant placement: A systematic review and meta-analysis.

OBJECTIVES: To systematically analyze the accuracy of robotic surgery for dental implant placement. MATERIALS AND METHODS: PubMed, Embase, and Cochrane CENTRAL were searched on October 25, 2023. Model studies or clinical studies reporting the accuracy of robotic surgery for dental implant placement among patients with missing or hopeless teeth were included. Risks of bias in clinical studies were assessed. Meta-analyses were undertaken. RESULTS: Data from 8 clinical studies reporting on 109 patients and 242 implants and 13 preclinical studies were included. Positional accuracy was measured by comparing the implant plan in presurgery CBCT and the actual implant position in postsurgery CBCT. For clinical studies, the pooled (95% confidence interval) platform deviation, apex deviation, and angular deviation were 0.68 (0.57, 0.79) mm, 0.67 (0.58, 0.75) mm, and 1.69 (1.25, 2.12)°, respectively. There was no statistically significant difference between the accuracy of implants placed in partially or fully edentulous patients. For model studies, the pooled platform deviation, apex deviation, and angular deviation were 0.72 (0.58, 0.86) mm, 0.90 (0.74, 1.06) mm, and 1.46 (1.22, 1.70)°, respectively. No adverse event was reported. CONCLUSION: Within the limitation of the present systematic review, robotic surgery for dental implant placement showed suitable implant positional accuracy and had no reported obvious harm. Both robotic systems and clinical studies on robotic surgery for dental implant placement should be further developed.

Does intra-oral scan improve the impression accuracy of full-arch implant-supported prostheses: A systematic review and meta-analysis.

OBJECTIVES: The present study aimed to systematically review the studies comparing the accuracy of intraoral scan (IOS) and conventional implant impressions (CI) in completely edentulous patients. MATERIALS AND METHODS: Electronic searches were performed in PubMed, Embase and Cochrane CENTRAL up to December 1, 2023. Clinical studies and in vitro studies reporting the accuracy of digital full arch impressions were included. The primary outcome is the 3-dimensional deviations between the study reference models. A risk of bias assessment was performed for clinical studies. A stratified meta-analysis and a single-armed meta-analysis were conducted. RESULTS: A total of 49 studies were included, with 8 clinical studies and 41 in vitro studies. For comparison between IOS and conventional impressions, studies were categorized into two groups based on the different measurement methods employed: RMS and CMM. In studies using RMS, the result favored the IOS in the unparalleled situation with the mean difference of -99.29 µm (95% CI: [-141.38, -57.19], I2 = 81%), while the result was opposite with the mean difference of 13.62 µm (95% CI: [10.97, 16.28], I2 = 26%) when implants were paralleled. For different brands of IOS, the accuracy ranged from 76.11 µm (95% CI: [42.36, 109.86]) to 158.63 µm (95% CI: [-14.68, 331.93]). CONCLUSIONS: Accuracy of intraoral scan is clinically acceptable in edentulous arches, especially for unparalleled implants. More clinical studies are needed to verify the present finding.

Improved positional accuracy of dental implant placement using a haptic and machine-vision-controlled collaborative surgery robot: A pilot randomized controlled trial.

AIM: To compare the implant accuracy, safety and morbidity between robot-assisted and freehand dental implant placement. MATERIALS AND METHODS: Subjects requiring single-site dental implant placement were recruited. Patients were randomly allocated to freehand implant placement and robot-assisted implant placement. Differences in positional accuracy of the implant, surgical morbidity and complications were assessed. The significance of intergroup differences was tested with an intention-to-treat analysis and a per-protocol (PP) analysis (excluding one patient due to calibration error). RESULTS: Twenty patients (with a median age of 37, 13 female) were included. One subject assigned to the robotic arm was excluded from the PP analysis because of a large calibration error due to the dislodgement of the index. For robot-assisted and freehand implant placement, with the PP analysis, the median (25th-75th percentile) platform global deviation, apex global deviation and angular deviation were 1.23 (0.9-1.4) mm/1.9 (1.2-2.3) mm (p = .03, the Mann-Whitney U-test), 1.40 (1.1-1.6) mm/2.1 (1.7-3.9) mm (p < .01) and 3.0 (0.9-6.0)°/6.7 (2.2-13.9)° (p = .08), respectively. Both methods showed limited damage to the alveolar ridge and had similar peri- and post-operative morbidity and safety. CONCLUSIONS: Robot-assisted implant placement enabled greater positional accuracy of the implant compared to freehand placement in this pilot trial. The robotic system should be further developed to simplify surgical procedures and improve accuracy and be validated in properly sized trials assessing the full spectrum of relevant outcomes.

[Osteotome sinus floor elevation with tapered implants: a short-term evaluation].

PURPOSE: The aim of this study was to evaluate the short-term clinical outcome of tapered implants placed in posterior maxilla with osteotome sinus floor elevation (OSFE) technique. METHODS: The study population comprised 40 patients in whom 44 Astra tapered implants were inserted with OSFE technique from March to September in 2019. The surgical indication was that the bone height below the maxillary sinus was considered to be 2mm ~8mm. Astra tapered implants were inserted. Prosthetic restoration was completed 4 months after surgery. The implant success rate and stability, as well as osseointegration of the implant were clinically evaluated, and bone gain around the implants were measured. The data were analyzed using SPSS 19.0 software package. RESULTS: During the study period,the implant survival rate was 100%. The mean variation of implant stability quotient(ISQ) was 12.07±5.86. The mean value of ISQ ranged from 67.55±8.07 to 79.62±5.08. The average marginal bone loss was (0.32±0.29) mm. The endo-sinus bone gain(ESBG) was (1.06±0.4) mm. No mechanical complication was observed. The average probing depth around the implant was (3.2±1.51) mm, the bleeding on probing rate was(11.36±4.28)%, and the modified plaque index was 1.23±0.43. CONCLUSIONS: Astra tapered implants were found to produce predictable results in osteotome sinus floor elevation surgery. Further properly designed clinical trials are required to validate the use of tapered dental implants in sinus floor elevation technique.

Accuracy of intraoral scan with prefabricated aids and stereophotogrammetry compared with open tray impressions for complete-arch implant-supported prosthesis: A clinical study.

OBJECTIVES: The aim of this clinical study was to compare the accuracy of intraoral scan system (IOS) with prefabricated aids and stereophotogrammetry (SPG) compared with open tray implant impression (OI) for complete-arch implant-supported fixed dental prostheses (CIFDP). MATERIALS AND METHODS: Patients needing CIFDP were enrolled in this study. OI, reference standard, IOS with prefabricated aids, and SPG were performed for each patient. Distance and angle deviations between all pairs of abutment analogs, root mean square (RMS) errors between the aligned test and reference model, and chairside time were measured. The effect of inter-abutment distance, jaw (maxilla or mandible), number of implants, and arch length on deviations was analyzed. The mixed effect model was applied to analyze deviations and RMS errors. RESULTS: Fifteen consecutive individuals (6 females and 9 males, 47-77 years old) with 22 arches (9 upper and 13 lower jaws) and 115 implants were included. There was no significant difference in distance deviation comparing SPG and IOS with OI (p > .05). IOS showed a significantly greater angle deviation and RMS errors than SPG (median 0.40° vs. 0.31°, 69 µm vs. 45 µm, p < .01). The inter-abutment distance was negatively correlated with the accuracy of SPG and IOS (p < .05). The chairside time for IOS, SPG, and OI was 10.49 ± 3.50, 14.71 ± 2.86, and 20.20 ± 3.01 min, respectively (p < .01). CONCLUSIONS: The accuracy of SPG and IOS with prefabricated aids was comparable. IOS was the most efficient workflow.

Accuracy and safety of a haptic operated and machine vision controlled collaborative robot for dental implant placement: A translational study.

OBJECTIVES: Multiple generations of medical robots have revolutionized surgery. Their application to dental implants is still in its infancy. Co-operating robots (cobots) have great potential to improve the accuracy of implant placement, overcoming the limitations of static and dynamic navigation. This study reports the accuracy of robot-assisted dental implant placement in a preclinical model and further applies the robotic system in a clinical case series. MATERIALS AND METHODS: In model analyses, the use of a lock-on structure at robot arm-handpiece was tested in resin arch models. In a clinical case series, patients with single missing teeth or edentulous arch were included. Robot-assisted implant placement was performed. Surgery time was recorded. Implant platform deviation, apex deviation, and angular deviation were measured. Factors influencing implant accuracy were analyzed. RESULTS: The in vitro results showed that with a lock-on structure, the mean (SD) of platform deviation, apex deviation, and angular deviation were 0.37 (0.14) mm, 0.44 (0.17) mm, and 0.75 (0.29)°, respectively. Twenty-one patients (28 implants) were included in the clinical case series, 2 with arches and 19 with single missing teeth. The median surgery time for single missing teeth was 23 (IQ range 20-25) min. The surgery time for the two edentulous arches was 47 and 70 min. The mean (SD) of platform deviation, apex deviation, and angular deviation was 0.54 (0.17) mm, 0.54 (0.11) mm, and 0.79 (0.22)° for single missing teeth and for 0.53 (0.17) mm, 0.58 (0.17) mm, and 0.77 (0.26)° for an edentulous arch. Implants placed in the mandible had significantly larger apex deviation than those in the maxilla. CONCLUSION: Cobot-assisted dental implant placement showed excellent positional accuracy and safety in both the in vitro study and the clinical case series. More technological development and clinical research are needed to support the introduction of robotic surgery in oral implantology. Trial registered in ChiCTR2100050885.

Buccal bone thickness and mid-facial soft tissue recession after various surgical approaches for immediate implant placement: A systematic review and network meta-analysis of controlled trials.

AIM: To evaluate the relative efficacy and confidence in the precision of the results of different surgical interventions for immediate implant placement in the anterior area. MATERIALS AND METHODS: Electronic searches were performed in PubMed, Embase, and Cochrane CENTRAL. Randomized controlled trials comparing different surgical techniques in anterior jaws for type 1 implant placement were included. Outcome measures included implant survival (primary outcome), buccal bone thickness (BBT) reduction, and mid-facial soft tissue recession (MSTR). Risks of bias assessment, network meta-analysis (NMA), sensitivity analysis, and quality-of-evidence assessment were performed. RESULTS: Twenty-two studies reporting on 948 subjects and 5 surgical interventions were included. Fourteen early failures were reported. Compared with open-flap surgery without tissue augmentation (F-N) and looking at BBT preservation, NMA showed that there was moderate confidence that flapless surgery with hard tissue augmentation (FL-HTA) was better than flapless surgery without tissue augmentation (FL-N) or open-flap surgery with hard tissue augmentation (F-HTA) (mean difference -0.8 mm, 95% confidence interval: -1.1 to -0.5 mm; -0.6 mm, -0.9 to -0.4 mm; and -0.5 mm, -0.7 to -0.3 mm, respectively). There was moderate confidence that flapless surgery with hard and soft tissue augmentation (FL-HTA&STA) could significantly prevent MSTR compared with FL-HTA (-0.5 mm, -0.7 to -0.3 mm) and FL-N (-0.6 mm, -1.2 to -0.04 mm). However, there was no significant additional benefit in BBT with the FL-HTA&STA approach compared to the FL-HTA approach (-0.30 mm, -0.81 to 0.21 mm). CONCLUSIONS: For immediate implant placement in the anterior areas, the FL-HTA approach better preserves BBT (moderate confidence); adding STA improves the stability of the mid-facial soft tissue level (moderate confidence) but at the expense of BBT (low confidence).

Accuracy of photogrammetric imaging versus conventional impressions for complete arch implant-supported fixed dental prostheses: A comparative clinical study.

STATEMENT OF PROBLEM: Clinical studies on the accuracy of the photogrammetric imaging technique for complete arch implant-supported fixed dental prostheses are lacking. PURPOSE: The purpose of this clinical study was to evaluate the accuracy (trueness) of photogrammetric imaging for complete arch implant-supported prostheses by comparing photogrammetric imaging with verified conventional splinted impressions. MATERIAL AND METHODS: Completely edentulous arches with at least 4 implants were included. Both photogrammetric imaging and conventional splinted impressions were performed in each jaw. The conventional casts were verified and scanned by using a laboratory scanner as the control. The distances and angulations between different implants (interimplant distances and interimplant angulations) were measured in all photogrammetric and conventional standard tessellation language (STL) files by using a reverse-engineering software program. The distance deviations between the photogrammetric and conventional impressions of the same participant were calculated as the primary outcome, and the angular deviations were obtained as the secondary outcome with descriptive analyses. The comparison between distance deviations and the clinically acceptable level of deviations (150 µm) was conducted by using the 1-sample t test. The effect of interimplant distances, interimplant angulations, and jaw (maxilla or mandible) on deviations was analyzed by using the Spearman correlation analysis, Kruskal-Wallis test, or Student t test, depending on the type of data (α=0.05 for all tests). RESULTS: Fourteen edentulous jaws were included. The overall distance deviation of photogrammetric imaging was 70 ±57 µm, significantly lower than the clinically acceptable level of misfit (150 µm; P<.001). The overall angular deviation was 0.432 ±0.348 degrees. The distance deviations were correlated with interimplant distances with a correlation coefficient (r) of 0.371 (P=.002). Interimplant angulation was not correlated with distance or angular deviations (P=.914, P=.914). Jaw was not correlated with distance or angular deviations either (P=.190, P=.209). CONCLUSIONS: The accuracy (trueness) of photogrammetric imaging of complete arch implant-supported prostheses was within a clinically acceptable range of errors. Distance deviations increased with greater interimplant distances. Interimplant angulations and jaw (maxilla or mandible) had no significant effect on the accuracy of photogrammetric imaging.

Clinical, radiographic, and esthetic evaluation of immediate implant placement with buccal bone dehiscence in the anterior maxilla: A 1-year prospective case series.

OBJECTIVES: To evaluate the clinical, radiographic, and esthetic outcomes of immediate implant placement with buccal bone dehiscence in the anterior maxilla. METHODS: In this case series, implants were inserted immediately after tooth extraction in sockets with buccal bone dehiscence. Guided bone regeneration (GBR) with a papilla preservation flap and simultaneous connective tissue grafting (CTG) was used. The following outcome variables were measured: mid-facial mucosal recession, probing depth, bleeding on probing, Pink Esthetic Score (PES), marginal bone loss, and thickness of buccal bone plate (TBP). RESULTS: 12 patients were recruited. Stable mid-facial mucosal level (-0.03 ± 0.17 mm) and excellent soft-tissue esthetic outcomes (PES, 9.17 ± 0.72) were achieved at 1 year. The TBP at platform level was 2.01 ± 0.31 mm at 1-year follow up with a resorption rate of 28.90% ± 15.14%. CONCLUSIONS: Immediate implant placement using GBR performed with a papilla preservation approach and simultaneous CTG is a feasible treatment procedure in compromised extraction sockets in the anterior region. Favorable esthetic outcomes and buccal bone thickness were obtained. Further studies were needed to evaluate the long-term tissue alteration.

Surgical interventions for implant placement in the anterior maxilla: A systematic scoping review with evidence mapping.

OBJECTIVES: Simplification and standardization of interventions are critical challenges to improving performance in implant dentistry. This study aimed to systematically identify and schematically present the evidence base of the implant dentistry surgical interventions for the anterior maxilla as a basis for further development and standardization. METHODS: Electronic searches were conducted in PubMed, Embase and Cochrane CENTRAL. Primary clinical studies reporting surgical interventions in the anterior maxilla, with a sample size of at least ten patients, were included. Bibliometric information and study details were extracted. Descriptive analysis and a mind map approach were used to describe the documentation of different surgical interventions. RESULTS: Two hundred and seventy-two studies reporting on 9001 patients were included. Within the past two decades, the number of literatures on implant placement in the anterior maxilla has increased dramatically (7 studies before 2005, 151 studies after 2016). Overall, the evidence map identified six primary operations and 33 variations. For hopeless tooth extraction, immediate implant placement was the most frequently reported (141 studies, 4670 patients); flapless implant placement with hard tissue augmentation and immediate provisionalization was the most commonly reported variation (33 studies, 987 patients). Type 3/4 implant placement (62 studies, 1902 patients) and implant site augmentation (33 studies, 788 patients) were frequently reported for missing teeth. Geographical differences were observed, with type 2 placement studies almost exclusively from Europe. CONCLUSIONS: Research on immediate implant placement was the most reported surgical intervention in the anterior maxilla. Hard tissue augmentation was frequently reported simultaneously with or before implant placement. Immediate provisionalization was mainly used for type 1 implant placement. The finding that six primary operations with 33 variations have been reported indicates the need for additional research to simplify and consolidate the surgical approach.

Clinical evaluation of narrow-diameter implants versus standard-diameter implants with lateral bone augmentation in posterior jaws: Three-year results of a randomized controlled trial.

BACKGROUND: The aim of this study was to compare the 3-year clinical outcomes of narrow-diameter implants (NDI) with standard-diameter implants (SDI) in conjunction with lateral bone augmentation in atrophic posterior jaws. MATERIALS AND METHODS: Fifty patients were included and randomly assigned into two groups: Patients in Group 1 received NDI (Ø3.5 mm); patients in Group 2 received SDI (Ø4.3 mm) with simultaneous lateral bone augmentation. Implant survival rates, complications, crestal bone loss, peri-implant conditions, treatment cost, and patient satisfaction were compared. RESULTS: Three patients dropped out the follow-up. No implant loss was observed. The difference in technical complication rates between the two groups was 3.8% (95% CI: -13.7% to 21.3%). No significant differences in crestal bone loss were found between two groups at 3-year follow-up (0.55 ± 0.76 vs 0.41 ± 0.41 mm, p = .429). A total of 20.8% (5/24) of NDI were diagnosed with mucositis and 8.3% (2/24) with peri-implantitis. A total of 17.4% (4/23) of SDI showed mucositis and (1/23) 4.3% showed peri-implantitis. The total cumulative cost of treatment per patient in Group 1 (2849.6 USD, 95% CI: 2726.8-2972.4) was significantly lower than that in Group 2 (3581.4 USD, 95% CI, 3460.9-3701.9) over the 3-year follow-up (p < .01). The patient satisfaction rating of operation was significantly higher in Group 1 (85.42 ± 7.41 vs 80.48 ± 7.95, p = .033). DISCUSSION: NDI yielded favorable implant survival, acceptable technical and biological complications, and high patient satisfaction supporting single crowns in the atrophic posterior region after 3-year follow-up. NDI might be a reasonable alternative in horizontally deficient posterior jaws. TRIAL REGISTRATION: Clinicaltrials.gov identifier: ChiCTR1800020426.

Effects of Dental Implants and Nutrition on Elderly Edentulous Subjects: Protocol for a Factorial Randomized Clinical Trial.

Background: Loss of masticatory function consequent to tooth loss has been associated with changes in food choices and insufficient nutritional intake. To date, interventions based on dental prostheses alone did not significantly improve nutrient intake. Pilot studies have shown positive impacts of interventions combining implant-supported fixed dental prosthesis with brief dietary advice. The relative contribution and the potential synergy of the components of such interventions need to be determined as it has major public health implications for the community-dwelling aging population that continues to disproportionately suffer from tooth loss and its consequences. Objective: To assess the effect of rehabilitation of masticatory function with fixed implant supported dentures and nutrition education in older subjects with terminal dentition (stage IV periodontitis) or full edentulism. Methods: A 2 × 2 factorial randomized controlled trial with 16-month follow-up of eligible adults (≥60 years) with loss of masticatory function consequent to full arch edentulism or terminal dentition (n = 120) will be conducted to test whether the rehabilitation of masticatory function with fixed implant supported dentures, nutrition education and/or their combination improves intake of fresh fruits and vegetables for aging subjects. The study has been designed to detect changes in fresh fruits and fresh vegetables intake at 4 months using the 24-h dietary recall method. Changes in protein as percentage of total energy, nutritional biomarkers, plasma metabolomics, oral and gut microbiome, quality of life and masticatory function will also be assessed. Discussion: We hypothesize that receiving rehabilitation of masticatory function with fixed implant dentures together with nutrition education is the most effective intervention for improving nutrient intake in aging community-dwelling subjects with extensive tooth loss. The results of this study will assist in designing better treatment regimens, guide medical care for individual subjects, and inform public health and policy. Clinical Trials Registration: NCT05334407.

Does machine-vision-assisted dynamic navigation improve the accuracy of digitally planned prosthetically guided immediate implant placement? A randomized controlled trial.

OBJECTIVES: This randomized controlled clinical trial was designed to compare the accuracy of machine-vision (MV)-based dynamic navigation (DN)-assisted immediate implant placement with the conventional freehand technique. MATERIAL AND METHODS: A total of 24 subjects requiring immediate implant placement in maxillary anterior teeth were randomly assigned to either the control (freehand by an experienced surgeon, n = 12) or the test group (MV-DN, n = 12). Implant platform, implant apex, angular, and depth deviations with respect to prosthetically guided digital planning and differences in implant insertion torque (ITV) and implant stability quotient (ISQ) were compared between the groups. RESULTS: MV-DN resulted in more accurate immediate implant position: significantly smaller global platform deviation (1.01 ± 0.41 mm vs. 1.51 ± 0.67 mm, p = .038), platform depth deviation (0.44 ± 0.46 mm vs. 0.95 ± 0.68 mm, p = .045), global apex deviation (0.88 ± 0.43 mm vs. 1.94 ± 0.86 mm, p = .001), and lateral apex deviation (0.68 ± 0.30 mm vs. 1.61 ± 0.88 mm, p = .004) were found in MV-DN compared to controls. No significant intergroup differences were observed for ITV and ISQ. CONCLUSIONS: MV-DN achieved more precise immediate implant position and comparable primary stability. Further trials are necessary to assess the benefits in terms of esthetics and tissue health/stability.

Long-term clinical outcomes of short implant (6mm) in relation to Implant Disease Risk Assessment (IDRA).

AIM: To evaluate the long-term survival of short implants and to investigate the association of the Implant Disease Risk Assessment (IDRA) with the occurrence of biological complications. MATERIAL AND METHODS: This study was designed as a cohort study with a median follow-up of 10.0 years. Patients who had received 6-mm implants were reviewed and assigned into low-, moderate-, and high-risk groups (Group L, M, and H) based on the IDRA tool. The implant survival, biological complications, soft tissue condition, hardware complications, and marginal bone loss (MBL) were evaluated. Kaplan-Meier curves and Cox regression were performed for survival analysis. RESULTS: A hundred and ten patients were included. The overall cumulative survival rate was 90.9% (L:100.0%, M: 93.3%, and H: 80.6%). A higher risk profile was significantly associated with a decreased implant survival (hazard ratio: 4.11, 95% CI: 1.17-14.36, p < .05). Higher risk profile (hazard ratio: 2.63, 95% CI: 1.32-5.25, p < .05) was a potential risk factor for biological complications. At follow-up, significant differences in bleeding index, modified plaque index, and peri-implant probing depth were found among groups (p < .01). No significant difference was found in MBL. CONCLUSION: Acceptable long-term clinical outcomes could be achieved after 10 years for short implants. Despite a statistically nonsignificant difference in MBL, patients with a high-risk profile of IDRA seem to be at greater risk of implant loss and biological complications.

Evidence and risk indicators of non-random sampling in clinical trials in implant dentistry: A systematic appraisal.

AIM: Analysis of distribution of p-values of continuous differences between test and controls after randomization provides evidence of unintentional error, non-random sampling, or data fabrication in randomized controlled trials (RCTs). We assessed evidence of highly unusual distributions of baseline characteristics of subjects enrolled in clinical trials in implant dentistry. MATERIALS AND METHODS: RCTs published between 2005 and 2020 were systematically searched in Pubmed, Embase, and Cochrane databases. Baseline patient data were extracted from full text articles by two independent assessors. The hypothesis of non-random sampling was tested by comparing the expected and the observed distribution of the p-values of differences between test and controls after randomization. RESULTS: One-thousand five-hundred and thirty-eight unique RCTs were identified, of which 409 (26.6%) did not report baseline characteristics of the population, and 671 (43.6%) reported data in forms other than mean and standard deviation and could not be used to assess their random sampling. Four-hundred and fifty-eight trials with 1449 baseline variables in the form of mean and standard deviation were assessed. The study observed an over-representation of very small p-values [<.001, 1.38%, 95% confidence interval (CI) 0.85-2.12 compared to the expected 0.10%, 95% CI 0.00-0.26]. No evidence of over-representation of larger p-values was observed. Unusual distributions were present in 2.38% of RCTs and more frequent in non-registered trials, in studies supported by non-industry funding, and in multi-centre RCTs. CONCLUSIONS: The inability to assess random sampling due to insufficient reporting in 26.6% of trials requires attention. In trials reporting suitable baseline data, unusual distributions were uncommon, and no evidence of data fabrication was detected, but there was evidence of non-random sampling. Continued efforts are necessary to ensure high integrity and trust in the evidence base of the field.

Accuracy and primary stability of tapered or straight implants placed into fresh extraction socket using dynamic navigation: a randomized controlled clinical trial.

OBJECTIVES: To compare the accuracy and primary stability of tapered and straight implants undergoing immediate implant placement with dynamic navigation. MATERIALS AND METHODS: Patients with compromised anterior teeth in maxilla were recruited and allocated randomly into (1) tapered implant group (TI group) and (2) straight implant group (SI group). Implants were inserted into fresh sockets with dynamic navigation. Three-dimensional platform deviation, apex deviation, angular deviation, insertion torque value (ITV) and implant stability quotient (ISQ) were recorded. RESULTS: Twenty patients with 20 implants were included. The overall platform, apex, and angular deviation were 0.87 ± 0.35 mm, 0.81 ± 0.34 mm, and 2.40 ± 1.31°, respectively. The accuracy was 0.86 ± 0.26 mm, 0.76 ± 0.33 mm, and 2.49 ± 1.54° for TI, and 0.89 ± 0.44 mm, 0.88 ± 0.36 mm, and 2.31 ± 1.01° for SI, with no significant difference (p = 0.85, 0.45, 0.76). Sagittal root position classification (SRP) class I may obtain greater error in numerical values in straight implants (0.97 ± 0.47 mm vs. 0.6 ± 0.16 mm, 0.92 ± 0.36 mm vs. 0.73 ± 0.36 mm, 2.48 ± 1.19° vs. 1.71 ± 0.14°). The overall ISQ was 60.74. ISQ was 60.48 for TI and 60.96 for SI, with no significant difference. Acceptable ITV (> 15 Ncm) was achieved in most of the included patients (SI 7/10, TI 9/10). CONCLUSIONS: High accuracy and primary stability of immediate implant placement could be achieved both in tapered and straight implants with dynamic navigation systems. CLINICAL RELEVANCE: Tapered and straight implants did not reach a consensus on which was better in immediate implant regarding to accuracy and primary stability. Our study demonstrated implant macrodesign did not affect accuracy and primary stability in immediate implant using dynamic navigation.

[Short-term comparison of the clinical efficacy of angulated screw-retained implant crowns and cemented implant crowns in esthetics region].

PURPOSE: To compare the clinical efficacy of angulated screw channel abutments and prefabricated titanium abutments on the restoration of single implant crowns in esthetics region. METHODS: The study was a prospective, single center, randomized controlled trial. Patients with the need of restoration of single tooth in esthetics region were included from June 2018 to June 2019. Forty patients were randomly assigned into two groups: screw-retained crowns with angulated screw channel abutments(angulated group, AG) and cemented crowns with prefabricated Ti abutments (cemented group, CG). Clinical and radiological evaluations were performed on the day of final crowns delivery and 6 months later. Implant survival rate, marginal bone loss (MBL), mechanical complications, peri-implant conditions (Probing depth, PD; bleeding on probing, BOP%), pink esthetics score/white esthetics score(PES/WES) and patients' satisfaction were assessed. The data was analyzed with SPSS 19.0 software package. RESULTS: Thirty-six patients (AG: 19, CG: 17) attended the 6-month clinical trial. Implant survival rates were both 100% in two groups. The MBL was (0.21±0.18) mm for AG and (0.38±0.40) mm for CG (P>0.05). The BOP% was significantly higher in AG than that in CG (P=0.04). No significant difference of mechanical complications, PD, PES/WES and patients' satisfaction was found between the two groups(P>0.05). CONCLUSIONS: Based on the present results, both treatment options show acceptable clinical outcomes in the short term. Angulated screw-retained crowns may benefit the peri-implant soft tissue; however, studies with long-term follow-up are needed to verify the results.

Single-Cell RNA Sequencing Identifies New Inflammation-Promoting Cell Subsets in Asian Patients With Chronic Periodontitis.

Periodontitis is a highly prevalent chronic inflammatory disease leading to periodontal tissue breakdown and subsequent tooth loss, in which excessive host immune response accounts for most of the tissue damage and disease progression. Despite of the imperative need to develop host modulation therapy, the inflammatory responses and cell population dynamics which are finely tuned by the pathological microenvironment in periodontitis remained unclear. To investigate the local microenvironment of the inflammatory response in periodontitis, 10 periodontitis patients and 10 healthy volunteers were involved in this study. Single-cell transcriptomic profilings of gingival tissues from two patients and two healthy donors were performed. Histology, immunohistochemistry, and flow cytometry analysis were performed to further validate the identified cell subtypes and their involvement in periodontitis. Based on our single-cell resolution analysis, we identified HLA-DR-expressing endothelial cells and CXCL13+ fibroblasts which are highly associated with immune regulation. We also revealed the involvement of the proinflammatory NLRP3+ macrophages in periodontitis. We further showed the increased cell-cell communication between macrophage and T/B cells in the inflammatory periodontal tissues. Our data generated an intriguing catalog of cell types and interaction networks in the human gingiva and identified new inflammation-promoting cell subtypes involved in chronic periodontitis, which will be helpful in advancing host modulation therapy.

Clinical, radiographic, and immunological evaluation of angulated screw-retained and cemented single-implant crowns in the esthetic region: A 1-year randomized controlled clinical trial.

BACKGROUND: Screw-retained implant crowns are considered more biologically compatible than cemented crowns due to the absence of excess cement. However, traditional screw-retained implant crowns are not viable when the access hole of the screw channel would need to be located in an esthetic area, which would compromise the esthetic outcome of the treatment. PURPOSE: To evaluate the clinical, radiographic, and immunological outcomes of angulated screw-retained and cemented single-implant crowns in the esthetic region. MATERIALS AND METHODS: The study was a single-center, open-label, randomized controlled clinical trial. Eligible patients were randomly placed in two groups: angulated screw-retained group (AG) and cemented group (CG). Implant survival rate, bleeding on probing rate (BOP%), probing depth (PD), modified plaque index (mPI), marginal bone loss (MBL), concentrations of pro-inflammatory cytokines (TNF-α, IL-6) in peri-implant crevicular fluid (PICF), mechanical complications, and pink esthetic score/white esthetic score (PES/WES) were evaluated. RESULTS: Fifty-six patients (AG: 29, CG: 27) attended the 1-year examination. The drop-out rate was 6.67%. No implant failure was found in both groups during the observation period. BOP% was significantly lower in the AG than that in the CG (mean, 21.84% ± 19.97% vs. 37.04% ± 26.28%, p = 0.018). The concentration of TNF-α in PICF was significantly higher in the AG than that in the CG (median, 13.54 vs. 4.62, p = 0.019). No significant difference of PD, mPI, MBL, IL-6, or mechanical complication rates was found between the two groups. Mean scores for PES/WES were 21.71 and 21.64 in the AG and CG, respectively. CONCLUSION: Based on the present results, both treatment options showed acceptable clinical outcomes in the short term. Angulated screw-retained crowns might benefit the peri-implant soft tissue. However, studies with long-term follow-up are needed to confirm whether the higher concentration of TNF-α will compromise the long-term outcomes of treatment.