Comparison of Different Intraoral Scanners With Prefabricated Aid on Accuracy and Framework Passive Fit of Digital Complete-Arch Implant Impression: An In Vitro Study.

OBJECTIVES: This study aimed to compare the accuracy of digital complete-arch implant impressions with prefabricated aids using three intraoral scanners (IOSs) and explore the correlation between virtual deviation measurement and physical framework misfit. MATERIALS AND METHODS: Four edentulous maxillary master models with four and six parallel and angular implants were fabricated and scanned by a laboratory scanner as reference scans. Ten scans of each master model were acquired using three IOSs (IOS-T, IOS-M, and IOS-A) with and without prefabricated aids. Trueness and precision of root mean square (RMS) errors were measured. Ten aluminum alloy frameworks were fabricated, and the misfit was measured with a micro-computed tomography scan with one screw tightened. RESULTS: Trueness and precision showed significant improvement when prefabricated aids were used for all three IOSs (p < 0.010). Median (interquartile range) RMS errors of trueness reduced from 67.5 (30.4) to 61.8 (30.3) µm, from 100.6 (35.4) to 45.9 (15.1) µm, and from 52.7 (33.2) to 41.1 (22.5) µm for scanner IOS-T, IOS-M, and IOS-A, respectively (p < 0.010). The precision of IOS-A and IOS-M was significantly better than IOS-T when using prefabricated aid (p < 0.001). RMS errors and the maximum marginal misfit of the framework were significantly correlated (p < 0.001, R2 = 0.845). CONCLUSIONS: With the prefabricated aids, the accuracy of IOSs enhanced significantly in digital complete-arch implant impressions. Three IOSs showed different levels of improvement in accuracy. Virtual RMS errors <62.2 µm could be the clinically acceptable threshold (150 µm) for framework passive fit.

Diet-related diseases mediate the effect of masticatory function on premature death in older adults.

AIM: Although poor oral health has been a potentially modifiable risk for mortality, the precise association between functional tooth units (FTUs) and premature death as well as the underlying mechanisms remains unclear. METHODS: This study used data from the National Health and Nutrition Examination Survey (NHANES) 2009-2018. Mortality details were obtained from the National Death Index (NDI). The number of FTUs was defined as pairs of opposing natural and artificial teeth in the premolar and molar area. Weighted logistic regression models were employed to assess the relationship between FTU and premature death. Demographic characteristics, lifestyle habits, and disease histories were adjusted as confounding factors. The propensity score matching (PSM) was conducted to further assess the association between FTU and premature death. Mediation analyses were conducted to assess the role of diet-related diseases in the association between FTU and premature death. RESULTS: The analysis included 4169 individuals aged between 60 and 74 years. Participants with 0 ≤ FTUs ≤ 3 had a significantly higher odds of premature death compared to the 10 ≤ FTUs ≤ 12 group (OR = 2.142, 95% CI 1.091-4.208). After missing data imputation, 0 ≤ FTUs ≤ 3 was still significantly associated with increased odds of premature death (OR = 2.115, 95% CI 1.125-3.975). The relationship between 0 ≤ FTUs ≤ 3 and reference group persisted (OR = 2.196, 95% CI 1.296-3.721) after PSM analyses. For mechanism, mediation analysis showed that diet-related diseases, including diabetes and hypertension, partially mediated the association between FTU and premature death with proportions of 5.089% and 8.437%, respectively. CONCLUSION: The findings revealed a link between impairment of masticatory function and a heightened odds of premature death among older adults. Notably, 0 ≤ FTUs ≤ 3 is significantly correlated to premature death among this demographic, with diabetes and hypertension partially mediating the effect of FTU on premature death. Further longitudinal studies are required to validate the findings.

Accuracy of traditional open-tray impression, stereophotogrammetry, and intraoral scanning with prefabricated aids for implant-supported complete arch prostheses with different implant distributions: An in vitro study.

STATEMENT OF PROBLEM: Conventional impression techniques for complete arch implant-supported fixed dental prostheses (CIFDPs) are technique sensitive. Stereophotogrammetry (SPG) and intraoral scanning (IOS) may offer alternatives to conventional impression making. PURPOSE: The purpose of this in vitro study was to assess the accuracy and passive fit of IOS with prefabricated aids, SPG, and open tray impression (OI) for CIFDPs with different implant distributions. MATERIAL AND METHODS: Three definitive casts with 4 parallel implants (4-PARA), 4 inclined implants (4-INCL), and 6 parallel implants (6-PARA) were fabricated. Three recording techniques were tested: IOS with prefabricated aids, SPG, and OI. The best and the worst scans were selected to fabricate 18 milled aluminum alloy frameworks. The trueness and precision of distance deviation (∆td and ∆pd), angular deviation (∆tθand ∆pθ), root mean square errors (∆tRMS for ∆pRMS), and passive fit score of frameworks were recorded. Two-way ANOVA was applied. RESULTS: SPG showed the best trueness and precision (95%CI of ∆td/∆tθ/∆tRMS, 31 to 39 µm, 0.22 to 0.28 degrees, 20 to 23 µm; 95%CI of ∆pd/∆pθ/∆pRMS, 9 to 11 µm, 0.06 to 0.08 degrees, 8 to 10 µm), followed by OI (61 to 83 µm, 0.33 to 0.48 degrees, 28 to 48 µm; 66 to 81 µm, 0.29 to 0.38 degrees, 32 to 41 µm) and IOS (143 to 193 µm, 0.37 to 0.50 degrees, 81 to 96 µm; 89 to 111 µm, 0.27 to 0.31 degrees, 51 to 62 µm). Tilted implants were associated with increased distance deviation. Increased implant number was associated with improved recording precision. The passive fit of frameworks was negatively correlated with the RMS error, and the correlation coefficient was -0.65 (P=.003). CONCLUSIONS: SPG had the best accuracy. Implant distributions affected implant precision. The RMS error can be used to evaluate the passive fit of frameworks.

Bovine-originated xenografts versus synthetic bone grafting materials in lateral maxillary sinus floor augmentation: A systematic review and meta-analysis.

AIMS: This study aimed to systematically compare the patients undergoing lateral MSFA therapies utilizing bovine-originated xenografts versus varied synthetic bone grafting materials. METHODS: Pubmed, Scopus, Embase, and Cochrane Library were searched up to April 2023, compensated by a manual search in selected journals. Studies reporting histological outcomes (residual bone graft, newly formed bone, non-mineralized tissue) and clinical outcomes (implant survival, ISQ value) were included. Several analyses were performed, including meta-analysis, sensitivity study, and Egger's regression tests. RESULTS: Sixteen clinical/randomized control trials were included in this systematic review, among which 12 were enrolled in a meta-analysis. The percentage of newly formed bone within the grafted sinuses by hybrid HA/TCP was significantly higher than those by xenografts (WMD 2.85, 95%CI [0.72; 4.99]), but those grafted by pure HA (WMD -1.72, 95%CI [-3.15; -0.29]) or TCP (WMD -7.10, 95%CI [-13.02; -1.17]) were significantly lower than xenograft counterparts. The residual bone graft and non-mineralized tissue yielded by synthetic HA, TCP, and HA/TCP showed no significant differences with the xenograft group. CONCLUSION: The chemistry of grafted bone substitutes in lateral MSFA influenced the quantity of newly formed bone. Those grafted with hybrid HA/TCP yielded the highest amount of new bone compared to bovine-originated HA. However, this influence was not significant on residual bone graft and non-mineralized tissue.

Association between masticatory function and depression in older adults: Results from NHANES 2009 to 2018.

AIM: Depression is prevalent among older adults. Although the number of missing teeth is considered to be associated with depression, the relationship between masticatory function, which is usually indicated by functional tooth units (FTUs), and depression in older adults remains unclear. MATERIALS AND METHODS: This study used data from the National Health and Nutrition Examination Survey (NHANES) 2009-2018. The number of FTUs was defined as pairs of opposing natural and artificial teeth. Depression was accessed using the Patient Health Questionnaire (PHQ-9), and participants who scored ≥10 on PHQ-9 were diagnosed with depression. Logistic regression analyses, propensity score matching (PSM) analyses and subgroup analyses were conducted to assess the association between FTU and depression. RESULTS: The analysis included 5764 individuals over 60 years. An association between FTU and the risk of depression among older adults was detected (odds ratio [OR] = 0.951, 95% confidence interval [CI] 0.915-0.989), suggesting protective roles of more FTUs. Significant increase in the risk of depression in 0 ≤ FTUs ≤ 3 was observed compared with 10 ≤ FTUs ≤ 12 (OR = 1.819, 95% CI 1.157-2.858). However, no significant increase in the risk of depression in 4 ≤ FTUs ≤ 9 was found. After PSM, significant increase in the risk of depression in 0 ≤ FTUs ≤ 3 was still detected compared with 4 ≤ FTUs ≤ 12 (OR = 1.484, 95% CI 1.030-2.136). Subgroup analyses demonstrated consistent results in all subgroups, except for individuals aged 76-80 and drinking regularly. CONCLUSIONS: The findings suggested the association between impaired masticatory function and the risk of depression among older adults. Longitudinal studies are needed to elucidate the role of masticatory function impairment in the development of depression further.

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.

Low energy intake and nutritional maladaptation in terminal stage IV periodontitis.

AIM: Impairment of masticatory function in elderly patients with terminal dentition due to stage IV periodontitis (TDS4P) may lead to lower nutritional intake. The study aimed to report the dietary intake and nutrition status of elderly patients with TDS4P and compare them with those of the elderly Chinese population and the Chinese Dietary Reference Intakes (DRIs). MATERIALS AND METHODS: Fifty-one consecutive subjects (≥55 years old) with TDS4P were enrolled. Average dietary intake was evaluated based on a 3-day 24-h dietary recall (24HR) and food frequency questionnaire (FFQ). The daily intake of fresh vegetables and fruits, dietary energy as well as macro and micronutrients were calculated and compared with matched national data and the Chinese DRIs. Nutritional status was assessed by Short-Form Mini-Nutritional assessment. RESULTS: Of the subjects, 19.6% (95% CI: 7.2%-28.1%) were at risk of malnutrition. The mean daily energy intake was 1517.4 kcal (95% CI: 1400.5-1634.3) for males and 1110.7 kcal (95% CI: 1001.5-1219.9) for females, which were very low compared with both the national data and the DRIs. Females derived a higher percentage of energy from fat. The mean daily intake of vegetables was 151.4 g (95% CI: 128.1-174.8) by FFQ and 130.9 g (95% CI: 104.6-157.3) by 24HR. Both results were significantly lower than the national reports (95% CI: 310.3-340.1) and the DRIs (300-450 g). Insufficient micronutrient intake, especially vitamins A, C and E, was also found. CONCLUSIONS: Elderly subjects with TDS4P had a lower daily energy intake, vegetable and fruit consumption and essential macro and micronutrient intake. More studies are needed to clarify the impact of periodontitis and tooth loss/replacement on nutrition and healthy ageing.

Impact of periodontitis on type 2 diabetes: a bioinformatic analysis.

BACKGROUND: Periodontitis is strongly associated with type 2 diabetes (T2D) that results in serious complications and mortality. However, the pathogenic role of periodontitis in the development of T2D and the underlain mechanism have not been fully elucidated. METHODS: A Mendelian randomization (MR) was performed to estimate the causality between two diseases. Bioinformatics tools, including gene ontology and pathway enrichment analyses, were employed to analyze the common differentially expressed genes (DEGs) in periodontitis and T2D. MR and colocalization analyses were then utilized to investigate the causal associations between potential pathogenic gene expression and the risk of T2D. Single cell-type expression analysis was further performed to detect the cellular localization of these genes. RESULTS: Genetically predicted periodontitis was associated with a higher risk of T2D (OR, 1.469; 95% CI, 1.117-1.930; P = 0.006) and insulin resistance (OR 1.034; 95%CI 1.001-1.068; P = 0.041). 79 common DEGs associated with periodontitis and T2D were then identified and demonstrated enrichment mainly in CXC receptor chemokine receptor binding and interleutin-17 signaling pathway. The integration of GWAS with the expression quantitative trait locis of these genes from the peripheral blood genetically prioritized 6 candidate genes, including 2 risk genes (RAP2A, MCUR1) and 4 protective genes (WNK1, NFIX, FOS, PANX1) in periodontitis-related T2D. Enriched in natural killer cells, RAP2A (OR 4.909; 95% CI 1.849-13.039; P = 0.001) demonstrated high risk influence on T2D, and exhibited strong genetic evidence of colocalization (coloc.abf-PPH4 = 0.632). CONCLUSIONS: This study used a multi-omics integration method to explore causality between periodontitis and T2D, and revealed molecular mechanisms using bioinformatics tools. Periodontitis was associated with a higher risk of T2D. MCUR1, RAP2A, FOS, PANX1, NFIX and WNK1 may play important roles in the pathogenesis of periodontitis-related T2D, shedding light on the development of potential drug targets.

Leveraging Large Language Models for Improved Patient Access and Self-Management: Assessor-Blinded Comparison Between Expert- and AI-Generated Content.

BACKGROUND: While large language models (LLMs) such as ChatGPT and Google Bard have shown significant promise in various fields, their broader impact on enhancing patient health care access and quality, particularly in specialized domains such as oral health, requires comprehensive evaluation. OBJECTIVE: This study aims to assess the effectiveness of Google Bard, ChatGPT-3.5, and ChatGPT-4 in offering recommendations for common oral health issues, benchmarked against responses from human dental experts. METHODS: This comparative analysis used 40 questions derived from patient surveys on prevalent oral diseases, which were executed in a simulated clinical environment. Responses, obtained from both human experts and LLMs, were subject to a blinded evaluation process by experienced dentists and lay users, focusing on readability, appropriateness, harmlessness, comprehensiveness, intent capture, and helpfulness. Additionally, the stability of artificial intelligence responses was also assessed by submitting each question 3 times under consistent conditions. RESULTS: Google Bard excelled in readability but lagged in appropriateness when compared to human experts (mean 8.51, SD 0.37 vs mean 9.60, SD 0.33; P=.03). ChatGPT-3.5 and ChatGPT-4, however, performed comparably with human experts in terms of appropriateness (mean 8.96, SD 0.35 and mean 9.34, SD 0.47, respectively), with ChatGPT-4 demonstrating the highest stability and reliability. Furthermore, all 3 LLMs received superior harmlessness scores comparable to human experts, with lay users finding minimal differences in helpfulness and intent capture between the artificial intelligence models and human responses. CONCLUSIONS: LLMs, particularly ChatGPT-4, show potential in oral health care, providing patient-centric information for enhancing patient education and clinical care. The observed performance variations underscore the need for ongoing refinement and ethical considerations in health care settings. Future research focuses on developing strategies for the safe integration of LLMs in health care settings.

Enhanced control of periodontitis by an artificial intelligence-enabled multimodal-sensing toothbrush and targeted mHealth micromessages: A randomized trial.

AIM: Treatment of periodontitis, a chronic inflammatory disease driven by biofilm dysbiosis, remains challenging due to patients' poor performance and adherence to the necessary oral hygiene procedures. Novel, artificial intelligence-enabled multimodal-sensing toothbrushes (AI-MST) can guide patients' oral hygiene practices in real-time and transmit valuable data to clinicians, thus enabling effective remote monitoring and guidance. The aim of this trial was to assess the effect of such a system as an adjunct to clinical practice guideline-conform treatment. MATERIALS AND METHODS: This was a single-centre, double-blind, standard-of-care controlled, randomized, parallel-group, superiority trial. Male and female adults with generalized Stage II/III periodontitis were recruited at the Shanghai Ninth People's Hospital, China. Subjects received a standard-of-care oral hygiene regimen or a technology-enabled, theory-based digital intervention consisting of an AI-MST and targeted doctor's guidance by remote micromessaging. Additionally, both groups received guideline-conform periodontal treatment. The primary outcome was the resolution of inflamed periodontal pockets (≥4 mm with bleeding on probing) at 6 months. The intention-to-treat (ITT) analysis included all subjects who received the allocated treatment and at least one follow-up. RESULTS: One hundred patients were randomized and treated (50 tests/controls) between 1 February and 30 November 2022. Forty-eight tests (19 females) and 47 controls (16 females) were analysed in the ITT population. At 6 months, the proportion of inflamed periodontal pockets decreased from 80.7% (95% confidence interval [CI] 76.5-84.8) to 52.3% (47.7-57.0) in the control group, and from 81.4% (77.1-85.6) to 44.4% (39.9-48.9) in the test group. The inter-group difference was 7.9% (1.6-14.6, p < .05). Test subjects achieved better levels of oral hygiene (p < .001). No significant adverse events were observed. CONCLUSIONS: The tested digital health intervention significantly improved the outcome of periodontal therapy by enhancing the adherence and performance of self-performed oral hygiene. The model breaks the traditional model of oral health care and has the potential to improve efficiency and reduce costs (NCT05137392).

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.

The potential causal path between periodontitis stage diagnosis and vegetable consumption is mediated by loss of posterior functional tooth units and masticatory function.

AIM: Emerging evidence points to a two-way relationship between periodontitis and dietary choices and, thus, nutrition. This study aimed to assess the potential cause-effect relationship between the periodontitis stage, loss of functional tooth units (FTUs), masticatory function, and intake of different food groups using path analysis. MATERIALS AND METHODS: A single calibrated examiner determined the periodontitis stage of a consecutive sample of 241 Chinese subjects reporting for tooth replacement. Their masticatory function was quantified by the mixing ability of a two-colour chewing gum. Validated food frequency questionnaires were used to calculate the intake of 33 food group items by an experienced calibrated rater. After verification of assumptions, visual structural equation modeling was performed with Amos 23. The consistency of results and the potential modifying effect of age were assessed in 9043 subjects from the NHANES database. RESULTS: Highly significant models were constructed using periodontitis stage and age as exogenous factors. Periodontitis stage diagnosis significantly affected the number of posterior FTUs and oral health-related quality of life (OHRQoL, path coefficient [PC] = -0.55 and -0.20, p < .05, respectively). In the model, FTUs also had an independent effect on OHRQoL (PC = 0.23, p < .05). FTUs determined the level of masticatory function (PC = -0.38, p < .05), which in turn affected vegetable intake but not fruit or meat intake (PC = -0.18, p < .0.5, PC = 0.06, NS and PC = 0.11, NS, respectively). The effect of age was significant for vegetable and meat intake and was also correlated with periodontitis stage diagnosis. Analysis of the NHANES database confirmed the negative impact of periodontitis on the number of occluding pairs and vegetable consumption for the 18-44, 45-60 and >60 age groups. CONCLUSIONS: Periodontitis showed a potential cause-effect pathway affecting vegetable intake across cultures and age groups. The size of the effect is potentially of clinical and public health significance. Additional studies, including intervention trials, are required to test this potential mechanism linking oral health to nutrition.

Dioscin Alleviates Periodontitis by Inhibiting NLRP3 Inflammasome Activation via Regulation of K+ Homeostasis and Mitochondrial Function.

Gingival inflammation and alveolar bone loss are characteristic manifestations of periodontitis. Interleukin (IL)-1ß, the maturation of which is mainly regulated by NOD-like receptor protein (NLRP) 3 inflammasome, not only amplifies the inflammatory response but also triggers osteoclastogenesis, thereby accelerating the progression of periodontitis. Dioscin, a natural steroid saponin, has been shown to inhibit NLRP3 inflammasome. Nevertheless, research on the effectiveness of Dioscin for the management of periodontitis remains scarce. In this study, Dioscin was found to dramatically reduce the integral components of NLRP3 inflammasome, ultimately limiting IL-1ß secretion. Notably, the inhibitory impact of Dioscin on NLRP3 inflammasome might be exerted by curbing the generation of mitochondrial (mt) reactive oxygen species (ROS) and oxidized (ox) mtDNA, which were mediated by inhibition of K+ efflux. Furthermore, Dioscin effectively alleviated periodontitis in mice. Overall, the results established that Dioscin could alleviate periodontitis by inhibiting NLRP3 inflammasome via modulation of the K+ efflux-mtROS-ox-mtDNA pathway, holding the potential to treat periodontitis and other NLRP3-driven inflammatory diseases.

Nerve Growth Factor-Preconditioned Mesenchymal Stem Cell-Derived Exosome-Functionalized 3D-Printed Hierarchical Porous Scaffolds with Neuro-Promotive Properties for Enhancing Innervated Bone Regeneration.

The essential role of the neural network in enhancing bone regeneration has often been overlooked in biomaterial design, leading to delayed or compromised bone healing. Engineered mesenchymal stem cells (MSCs)-derived exosomes are becoming increasingly recognized as potent cell-free agents for manipulating cellular behavior and improving therapeutic effectiveness. Herein, MSCs are stimulated with nerve growth factor (NGF) to regulate exosomal cargoes to improve neuro-promotive potential and facilitate innervated bone regeneration. In vitro cell experiments showed that the NGF-stimulated MSCs-derived exosomes (N-Exos) obviously improved the cellular function and neurotrophic effects of the neural cells, and consequently, the osteogenic potential of the osteo-reparative cells. Bioinformatic analysis by miRNA sequencing and pathway enrichment revealed that the beneficial effects of N-Exos may partly be ascribed to the NGF-elicited multicomponent exosomal miRNAs and the subsequent regulation and activation of the MAPK and PI3K-Akt signaling pathways. On this basis, N-Exos were delivered on the micropores of the 3D-printed hierarchical porous scaffold to accomplish the sustained release profile and extended bioavailability. In a rat model with a distal femoral defect, the N-Exos-functionalized hierarchical porous scaffold significantly induced neurovascular structure formation and innervated bone regeneration. This study provided a feasible strategy to modulate the functional cargoes of MSCs-derived exosomes to acquire desirable neuro-promotive and osteogenic potential. Furthermore, the developed N-Exos-functionalized hierarchical porous scaffold may represent a promising neurovascular-promotive bone reparative scaffold for clinical translation.

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.

One-piece versus two-piece zirconia abutment supported single implant crown in the esthetic region: 3-Year results from a split-mouth randomized controlled clinical trial.

OBJECTIVES: To compare the clinical, radiographic, and immunological outcomes between one-piece versus two-piece zirconia abutments supported single implant crowns in the esthetic region. MATERIALS AND METHODS: The study followed a split-mouth, double-blind, and randomized controlled clinical design for a duration of 3 years. Twenty-two eligible patients with 44 implants were randomly assigned to two groups: Group 1 (one-piece zirconia abutment with zirconia base, n = 22) and Group 2 (two-piece zirconia abutment with titanium base, n = 22). The primary outcome was the technical complication rate. Additionally, survival rates, cytokines concentrations in peri-implant crevicular fluid (PICF), peri-implant conditions, marginal bone loss, and pink/white esthetics score (PES/WES) were assessed as secondary outcomes. RESULTS: Twelve of 22 patients attended the 1-year follow-up (due to the COVID pandemic), and 19 patients attended the 3-year examination. Two abutments in Group 1 were fractured after 10 and 12 months in function. Additionally, one screw loosening occurred in Group 1 at 1-year follow-up. The 3-year technical complication rate was significantly higher in Group 1 than that in Group 2 (15.79% vs. 0%, p < .001). The 3-year implant survival rate was 100% in both groups. The concentration of IFN-γ in PICF was significantly upregulated in Group 2 (p = .018). Furthermore, the IL-6 concentration was positively correlated with BOP% (p = .020). CONCLUSIONS: Two-piece zirconia abutments exhibited superior technical performance compared to one-piece designs during a 3-year follow-up in the anterior region. However, further long-term research is necessary to verify the immunological stability of two-piece zirconia abutments.

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.