Effect of implant shape and length on the accuracy of robot-assisted immediate implant surgery: An in vitro study.

OBJECTIVES: To compare the accuracy of immediate implant placement of cylindrical implants (CI) and tapered implants (TI) of different lengths using a robotic dental implant system. MATERIALS AND METHODS: CI and TI of three lengths (8, 10, and 12 mm) each were digitally planned and placed in a three-dimensional printed extraction socket model under robotic guidance. There were six groups with three samples in each group, resulting in a total of 18 samples. Implant angular deviation, platform point deviation (total, lateral, depth), and implant apical point deviation (total, lateral, depth) were recorded and compared between the different groups. RESULTS: The angular deviations for CI 8 mm, CI 10 mm, CI 12 mm, TI 8 mm, TI 10 mm, and TI 12 mm were 1.32° ± 0.19°, 1.03° ± 0.56°, 1.31° ± 0.38°, 1.27° ± 0.64°, 1.10° ± 0.43° and 1.05° ± 0.45°, respectively. The total deviations of platform and apical points for CI 8 mm, CI 10 mm, CI 12 mm, TI 8 mm, TI 10 mm, and TI 12 mm were 0.79 ± 0.18 mm, 0.77 ± 0.33 mm; 0.64 ± 0.21 mm, 0.55 ± 0.17 mm; 0.64 ± 0.37 mm, 0.65 ± 0.34 mm; 0.68 ± 0.26 mm, 0.71 ± 0.20 mm; 0.70 ± 0.12 mm, 0.66 ± 0.23 mm; and 0.71 ± 0.15 mm, 0.77 ± 0.29 mm, respectively, and had no significant differences. CONCLUSIONS: Within the limitation of this study, acceptable accuracy can be achieved for both TI and CI using robotic systems. Our study demonstrated that the implant shape and length did not affect the accuracy of immediate implant placement under robotic guidance in vitro. However, further trials are required to confirm their efficacy in clinical practice.

Identification of novel candidate biomarkers related to immune cell infiltration in peri-implantitis.

OBJECTIVE: The present study was performed to identify key biomarkers associated with immune cell infiltration in peri-implantitis through bioinformatic analyses. METHODS: Six peri-implantitis soft tissue samples and six healthy gingiva samples were obtained from GSE106090, and were used to identify immune-associated differentially expressed genes (DEGs) in peri-implantitis. The candidate biomarkers associated with immune cell infiltration were examined by immunohistochemical staining. RESULTS: We identified 2089 upregulated and 2173 downregulated genes. Upregulated DEGs were significantly associated with immune response. Ten key candidate biomarkers were identified in the PPI network, including IL1B, TLR2, TLR4, CCL4, CXCL8, IL10, IL6, CD4, CCL3, and PTPRC. The expression level of the 10 genes increased in peri-implantitis soft tissue samples compared with healthy gingiva samples. The proportion of CD4+ T cells, iTreg, and Tfh in infiltration immune cells increased in peri-implantitis soft tissue samples and were positively correlated with the expression level of candidate biomarkers TLR4, CCL3, CXCL8, and IL1B. Immunohistochemistry showed that there were more lymphocytes in peri-implantitis soft tissue samples, with an increased expression level of TLR4, CCL3, CXCL8, and IL1B. CONCLUSION: Identification of four novel diagnostic biomarkers was helpful for revealing the molecular mechanisms and could serve as a risk predictor for the immune microenvironment in peri-implantitis.

Influence of dental implant clinical experience on the accuracy of robot-assisted immediate implant placement: an in vitro study.

OBJECTIVES: To assess the accuracy and effectiveness among operators with different levels of experience in a robot-assisted immediate implant surgery. MATERIALS AND METHODS: The study included four participants who had received dental training at the same institution but have varying levels of clinical experience in implant dentistry, denoted as undergraduate student (UG), dental resident (DR), specialist with no robot experience (IS) and specialist with robot experience (RS). Following comprehensive theoretical training in robot-assisted implant operation, each operator participated in five robotic-assisted implant procedures at 21 sites, resulting in the implant surgery of a total of 20 implants. Subsequently, the accuracy of the implants was assessed by analyzing the preoperative planning and the postoperative CBCT scans, and the time required for each procedure was also recorded. RESULTS: Angular deviation in UG, DR, IS and RS group was 0.82 ± 0.27°, 0.55 ± 0.27°, 0.83 ± 0.27°, and 0.56 ± 0.36°, respectively. The total deviation of the implant platform point was 0.28 ± 0.10 mm, 0.26 ± 0.16 mm, 0.34 ± 0.08 mm and 0.31 ± 0.06 mm, respectively. The total deviation of the apical point was 0.30 ± 0.08 mm, 0.25 ± 0.18 mm, 0.31 ± 0.09 mm, and 0.31 ± 0.05 mm, respectively. The time spent was 10.37 ± 0.57 min, 10.56 ± 1.77 min, 9.93 ± 0.78 min, and 11.76 ± 0.78 min for each operator. As the number of operations increased, the operation time decreased, but there was no significant difference in implant accuracy between the different groups. CONCLUSIONS: Within the scope of this study, robot-assisted implant surgery demonstrated high accuracy, with no significant differences in performance between operators with varying levels of clinical experience or implant robot-user experience. Furthermore, the learning curve for robotic implant surgery is steep and consistent. CLINICAL RELEVANCE: Robot-assisted implant surgery demonstrates consistent high accuracy across operators of varying clinical and robotic experience levels, highlighting its potential to standardize procedures and enhance predictability in clinical outcomes.

Does dynamic navigation assisted student training improve the accuracy of dental implant placement by postgraduate dental students: an in vitro study.

OBJECTIVES: To assess the accuracy of implant placement in models and satisfaction in dynamic navigation assisted postgraduate dental students training. METHODS: Postgraduate dental students who had at least one year of dental clinical practice with no experience in dental implant surgeries were included. Students were instructed to make treatment plans in the dynamic navigation system. Each student placed two maxillary right incisors, using freehand approach at first and then under dynamic navigation. The implant position was compared with treatment plan. Factors influencing the accuracy of implants placed under dynamic navigation were analyzed. Student acceptance towards the training and use of dynamic navigation was recorded using a questionnaire. RESULTS: A total of 21 students placed 42 implants. For freehand implant placement, the median entry point deviation, apex point deviation, and implant axis deviation was 3.79 mm, 4.32 mm, and 10.08°. For dynamic guided implant placement, the median entry point deviation, apex point deviation, and implant axis deviation was 1.29 mm, 1.25 mm, and 4.89° (p < 0.001). The accuracy of dynamic guided implant was not influenced by student gender or familiarity with computer games. All students were satisfied with the training. CONCLUSIONS: Dynamic navigation system assisted students in improving the accuracy of implant placement and was well accepted by students.

Multiscale Relaxation Behavior of Amorphous Plasticized Poly(vinyl butyral).

As a key component in laminated glass, plasticized polyvinyl butyral (PVB) interlayer is a kind of impact-resistant polymer material with high toughness. Recently, by using ultrasmall angle X-ray scattering (USAXS) technique, Stretch-induced phase-separated structure on the scale of hundreds of nanometers formed in plasticized PVB for the first time is reported. In this work, the multiscale relaxation behavior of plasticized PVB is further investigated. The relaxation behavior of deformed plasticized PVB is studied from macroscopic stress, mesoscopic phase-separated structure, and microscopic chain segment by combining USAXS, and birefringence with in situ stretching device. The contributions of chain segments and hydrogen bonding clusters for the multiscale relaxation behavior are discussed.

Radiographic comparison of atelocollagen versus deproteinized bovine bone minerals covered with a collagen membrane in alveolar ridge preservation: a retrospective study.

BACKGROUND: Atelocollagen (AC) is a low-immunogenic collagen derivative with longer degradation time, which can be a suitable material for alveolar ridge preservation (ARP). However, there are few human studies on AC using for ARP. This research aims to radiographically evaluate the efficacy of AC in comparison to deproteinized bovine bone minerals covered with a collagen membrane (DBBM/CM) in ARP. METHODS: Medical records in the Implantology Department of the Hospital of Stomatology of Wuhan University were screened for patients who received flapless ARP using either AC or DBBM/CM. A total of 58 patients were included in this retrospective study. 28 patients were treated with AC, while 30 patients were used DBBM/CM. Cone-beam computed tomography (CBCT) scans were taken before extraction and after 6 months of healing. To assess the dimensional change of the extraction sockets, the scanning data were output and transferred to the digital software to measure horizontal bone width change, vertical bone height change and bone volume change in region of interest. To evaluate the bone quality of healed sockets, the bone density of virtual implants was evaluated. RESULTS: The horizontal bone width changes at all five different levels showed no significant difference between the two groups. The largest horizontal bone width decrement in both groups occurred at the crest of ridge, which decreased 3.71 ± 1.67 mm in AC group and 3.53 ± 1.51 mm in DBBM/CM group (p = 0.68). At the central buccal aspect, the ridge height reduced 0.10 ± 1.30 mm in AC group, while increased 0.77 ± 2.43 mm in DBBM/CM group (p = 0.10). The vertical bone height differences between two groups showed no statistical significance. The percentages of volume absorption in AC group and DBBM/CM group were 12.37%±6.09% and 14.54%±11.21%, respectively. No significant difference in volume absorption was found (p = 0.36). The average bone density around virtual implants in AC group (649.41 ± 184.71 HU) was significantly lower than that in DBBM/CM group (985.23 ± 207.85 HU) (p < 0.001). CONCLUSIONS: ARP with AC had a similar effect on limiting the dimensional alteration of alveolar ridge, when radiographically compared with DBBM/CM.

The reporting and methodological quality of split-mouth trials in oral implantology: A methodological study.

OBJECTIVES: The objective of this study is to assess the reporting and methodological quality of split-mouth trials (SMTs) in oral implantology published during the past 10 years, and to investigate whether there was any improvement over time. MATERIALS AND METHODS: We searched PubMed for SMTs in oral implantology published during 2011-20. We used CONSORT 2010, its extension for within-person trial (WPT), and an SMT-specific methodological checklist to assess trial reporting quality (TRQ), WPT-specific reporting quality (WRQ), and SMT-specific methodological quality (SMQ), respectively. Binary scores were given to each item, and total scores of TRQ (range 0-32), WRQ (0-15), and SMQ (0-3) were calculated for each study. Multivariable regression analyses were performed to compare the quality of SMTs published before (2011-17) and after (2018-20) the release of CONSORT for WPT. RESULTS: Seventy-nine SMTs were included. The mean TRQ, WRQ, and SMQ were 16.4, 6.7, and 1.3, respectively. Less than one-third (n = 25, 31.6%) reported the rationale for using split-mouth designs. Only 4 (5.1%) trials adequately conducted sample size calculation, and 40 (50.6%) used appropriate statistical methods that considered dependency and clustering of data. In multivariable analyses, compared with 2011-17, studies published in 2018-20 had significantly higher TRQ (p = .044), while WRQ and SMQ did not show improvement. CONCLUSIONS: The reporting and methodological quality of SMTs in oral implantology need to be improved. Joint efforts are needed to improve the reporting and methodology of SMTs in this field.

The benefit of antimicrobial photodynamic therapy to mechanical debridement in the treatment of smokers with peri-implant diseases: a systematic review and meta-analysis.

Antimicrobial photodynamic therapy (aPDT) has been proposed as an adjunctive treatment strategy for peri-implant diseases. This systematic review aimed to determine whether aPDT as an adjunct to mechanical debridement has an additional benefit for smokers with peri-implant diseases. Randomized controlled trials (RCTs), which evaluated the clinical outcomes of mechanical debridement alone versus mechanical debridement + aPDT among smokers, were considered eligible to be included. The primary outcome was bleeding on probing (BOP) and secondary outcomes included probing depth (PD), plaque index (PI), and crestal bone loss (CBL). Meta-analyses using a random-effects model were conducted to calculate the mean difference (MD) with a 95% confidence interval (CI). The quality of evidence was assessed according to Grading of Recommendations Assessment, Development and Evaluation (GRADE). A total of four RCTs (188 participants) were included. The aPDT group showed significantly improved PD (MD = - 1.26, 95% CI = - 2.19 to - 0.32, p = 0.008) and PI (MD = - 10.6%, 95% CI = - 14.46 to - 6.74%, p = 0.0001) compared with mechanical debridement group at 3-month follow-up. No significant difference in bleeding on probing (BOP) was observed at 3-month follow-up (MD = - 0.60%, 95% CI = - 2.36 to 1.16%, p = 0.50). The subgroup analyses on photosensitizers demonstrated significant differences between the two groups on PD (MD = - 1.23, 95% CI = - 2.41 to - 0.05, p = 0.04) and PI (MD = - 12.33, 95% CI = - 14.74 to - 9.92, p < 0.00001) by the use of methylene blue (MB). Within the limitation of this study, compared with mechanical debridement alone, combined use of aPDT was more effective in reducing PD and PI in smokers at 3-month follow-up. MB was a predictable photosensitizer for aPDT. However, the findings should be interpreted with caution due to the limited number of included studies, methodological deficiencies, and heterogeneity between studies.

Are short implants (≤8.5 mm) reliable in the rehabilitation of completely edentulous patients: A systematic review and meta-analysis.

STATEMENT OF PROBLEM: Limited data are available regarding the reliability of short implants (≤8.5 mm) in patients with resorbed completely edentulous jaws. PURPOSE: The purpose of this systematic review and meta-analysis was to compare the clinical outcomes of short implants (intervention) versus long implants (≥10 mm, comparison) in the rehabilitation of completely edentulous jaws. MATERIAL AND METHODS: The PubMed, Embase, and Cochrane CENTRAL databases were searched for randomized controlled trials (RCTs) comparing short and long implants supporting fixed or removable prostheses in completely edentulous jaws. Outcome measures included implant survival, marginal bone loss (MBL), and biological and technical complications. The risks of bias within and across the studies were assessed, and meta-analyses, sensitivity analyses, and subgroup analyses by types of prostheses, jaw locations, and follow-up length were performed. RESULTS: A total of 4 RCTs with 158 participants were included. No significant difference was found between short implants and long implants regarding implant survival (RR=1.01, 95% CI: 0.97 to 1.05, P=.710, I2=70%) or MBL (MD=-0.19 mm, 95% CI: -0.39 to 0.02, P=.070, I2=94%). In subgroup analyses, when supporting fixed prostheses, short implants showed significantly less MBL than long implants (P<.001). In the mandible, short implants showed higher implant survival (P=.008) and less MBL (P<.001). Participants receiving long implants combined with bone augmentation procedures reported more postsurgery pain. CONCLUSIONS: For completely edentulous jaws, short implants provide a reliable treatment alternative, as survival and MBL were not different when compared with those of long implants. However, additional high-level evidence is still needed to determine the long-term clinical outcomes of short implants in completely edentulous jaws.

Trends in the level of evidence and impact of clinical studies published in leading oral implantology journals: 2008-2018.

OBJECTIVES: To present the characteristics and level of evidence (LOE) of clinical studies published in leading oral implantology journals during 2008-2018 and to explore whether the LOE of a study is associated with its scientific and social impact. MATERIALS AND METHODS: Clinical studies with direct relevance to the evaluation of healthcare interventions published in 2008, 2013, and 2018 in six oral implantology journals were identified via hand searches. A modified 4-level Oxford 2011 LOE tool was used to assess the LOE of all eligible studies. The citation count and Altmetric Attention Score (AAS) of each study were extracted from Web of Science and Altmetric Explorer, respectively. Thereafter, multivariable generalized estimation equation analyses were used to investigate the association between LOE, citation counts, and AAS, adjusting for potential confounding factors and clustering effects. RESULTS: A total of 763 clinical studies were included, among which the proportion of level-1, level-2, level-3, and level-4 studies was 2.4%, 30.4%, 40.2%, and 27.0%, respectively. During 2008-2018, the proportion of high LOE studies (level-1 and level-2) increased substantially from 24.6% to 43.1%, although the number of systematic reviews that only include randomized controlled trials has remained limited. According to multivariable analyses, the citation count (p = .002) and AAS (p = .005) of high LOE studies were both significantly greater than those of low LOE studies. CONCLUSIONS: During the past decade, the proportion of high LOE studies has increased substantially in the field of oral implantology. Clinical studies with higher LOE tend to have greater scientific and social impact.

Pharmaceutical micelles featured with singlet oxygen-responsive cargo release and mitochondrial targeting for enhanced photodynamic therapy.

The efficacy of nanoparticulate photodynamic therapy is often compromised by the short life time and limited diffusion radius of singlet oxygen as well as uncontrolled intracellular distribution of photosensitizer. It was hypothesized that rapid photosensitizer release upon nanoparticle internalization and its preferred accumulation in mitochondria would address the above problems. Hence, the aim of this study was to engineer a multifunctional micellar nanosystem featured with singlet oxygen-responsive cargo release and mitochondria-targeting. An imidazole-bearing amphiphilic copolymer was employed as the micelle building block to encapsulate triphenylphosphonium-pyropheophorbide a (TPP-PPa) conjugate or PPa. Upon laser irradiation, the singlet oxygen produced by TPP-PPa/PPa oxidized the imidazole moiety to produce hydrophilic urea, leading to micelle disassembly and rapid cargo release. The co-localization analysis showed that the TPP moiety significantly enhanced the photosensitizer uptake by mitochondria, improved mitochondria depolarization upon irradiation, and hence boosted the cytotoxicity in 4T1 cells. The targeting strategy also dramatically reduced the intracellular ATP concentration as a consequence of mitochondria injury. The mitochondria damage was accompanied with the activation of the apoptosis signals (caspase 3 and caspase 9), whose level was directly correlated to the apoptosis extent. The current work provides a facile and robust means to enhance the efficacy of photodynamic therapy.

[The Effect of Concentrate Growth Factors on the Survival, Proliferation and Differentiation of Human Dental Pulp Cells].

OBJECTIVE: To explore the cytotoxicity of concentrate growth factors (CGF) and the effects on the apoptosis, proliferation and differentiation of human dental pulp cells (hDPCs), which were closely correlated with future application of CGF in the treatment of dental pulpal and periapical diseases. METHODS: hDPCs were isolated from permanent teeth extracted for orthodontic purpose, and expanded in vitro. hDPCs were treated with CGF and mineral trioxide aggregate (MTA) respectively. The cell apoptosis, proliferation, cell cycle and ALP activity were analyzed after 1, 3 and 7 days. RESULTS: Compared with the MTA group, CGF significantly promoted cell proliferation, increased the proportion of S-phase cells and ALP activity on days 3 and 7 (P<0.01). Besides, hDPCs apoptotic rates decreased in CGF group. CONCLUSION: CGF has a good ability to promote the proliferation of dental pulp cells, resist apoptosis and induce osteogenic/odontogenic differentiation in vitro.

Patients Are More Satisfied With Implant-Supported Mandibular Overdentures Than With Conventional Dentures.

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: Comparison of implant supported mandibular overdentures and conventional dentures on quality of life: a systematic review and meta-analysis of randomized controlled studies. Sivaramakrishnan G, Sridharan K. Aust Dent J. 2016; 61(4):482-8. SOURCE OF FUNDING: The authors received no financial support for this study. TYPE OF STUDY/DESIGN: Systematic review.

What are patients' expectations of orthodontic treatment: a systematic review.

BACKGROUND: What patients expect to happen during treatment or benefit from the treatment might influence the subsequent factors such as treatment outcome, patient satisfaction, patient's cooperation as well as compliance. The aim of this systematic review is to assess the role of patients' expectations from orthodontic treatment. METHODS: A systematic literature search of four databases Pubmed, Cochrane, Web of Science and PsychINFO was conducted following PRISMA guidelines. Studies reporting expectations regarding orthodontic treatment were selected and a narrative review was conducted. The quality of study was rated according to STROBE statements and the methodology as well as key findings were summarized. RESULTS: Thirteen studies (14 papers) were finally included for analysis. Among them, only one was a randomized control trial, while the rest included one cohort study, two questionnaire-developments and ten cross-sectional studies. The STROBE quality of reporting scores of the studies ranged from 12 to 18. Seven papers described expectations of the treatment experiences, along with seven talking about benefit expectations from the treatment. Dental appearance and function improvement were most expected in studies relate to the treatment benefits. CONCLUSIONS: Orthodontics appears to have adopted various standardized questionnaires. However, most of them are poor in the quality of methodology and results analyses, which prohibit synthesizing sufficient evidence to help identify which factors influence patient expectations. The evidence of "expectations" affecting treatment outcomes is not found in current research. Future studies are needed to better understand the impact of "expectation" on the treatment both theoretically and experimentally.

Effects of Er-Zhi-Wan on microarchitecture and regulation of Wnt/ß-catenin signaling pathway in alveolar bone of ovariectomized rats.

Recent studies have shown that Er-Zhi-Wan (EZW), a traditional Chinese medicine consisting of Herba Ecliptae (HE) and Fructus Ligustri Lucidi (FLL), had a definite antiosteoporotic effect on osteoporotic femur, but its effect on osteoporosis of alveolar bone remains unknown. In the present study, we investigated the effects of Er-Zhi-Wan (EZW) on the microarchitecture and the regulation of Wnt/ß-catenin signaling pathway in the alveolar bone of ovariectomized rats. Thirty Sprague-Dawley rats were randomly divided into three groups: sham operation group (sham, n=10), ovariectomy (OVX) group (n=10), and OVX with EZW treatment group (EZW group, n=10). From one week after ovariectomy, EZW (100 mg/mL) or vehicle (distilled water) was fed (1 mL/100 g) once per day for 12 weeks until the sacrifice of the rats. The body weights were measured weekly. After sacrifice, the sera and mandible were collected and routinely prepared for the measurement of alveolar trabecular microarchitecture, serum levels of E2, bone-specific alkaline phosphatase (BALP) and tartrate-resistant acid phosphatase 5b (TRAP5b), as well as mandibular mRNA expression of Wnt/ß-catenin signaling pathway molecules wnt3a, low-density lipoprotein receptor-related protein 5 (LRP5), ß-catenin and dickkopf homolog 1 (DKK1). The results showed that EZW treatment significantly prevented the body weight gain, degradation of alveolar trabecular microarchitecture and alveolar bone loss in the OVX rats. Furthermore, we observed that EZW could increase the serum levels of E2 and BALP, and decrease levels of serum TRAP5b in EZW group compared with vehicle group. In addition, RT-PCR results revealed that EZW upregulated the expression levels of wnt3a, LRP5 and ß-catenin, and reduced the expression of DKK1 in OVX rats. Taken together, our results suggested that EZW may have potential anti-osteoporotic effects on osteoporotic alveolar bone by stimulating Wnt/LRP5/ß-catenin signaling pathway.

A transcrestal sinus floor elevation strategy based on a haptic robot system: An in vitro study.

OBJECTIVES: To reveal the force profiles recorded by haptic autonomous robotic force feedback during the transcrestal sinus floor elevation (TSFE) process, providing a reference for the surgery strategy during TSFE. MATERIALS AND METHODS: A total of 42 maxillary sinus models with different angles of the sinus floor (30°, 40°, 50°, 60°, 70°, 80°, and 90°, compared to vertical plane) were 3D printed. Implant site preparation was performed using a robotic system, and the total force (Ft) and axial force along the drill (Fz) during the surgery were recorded by the haptic robotic arm. The actual initial breakthrough point (drill contacting sinus floor) and complete breakthrough point (drill penetrating the sinus floor) were defined visually (the actual IBP and the actual CBP). The theoretical initial breakthrough point (the theoretical IBP) and the theoretical complete breakthrough point (the theoretical CBP) defined by the robot-guided system and the CBCT were determined by real-time force feedback and imaging distance measurement, respectively. The distance from the bottom of the resin model to the actual IBP and the actual CBP was defined as Di and Dt, respectively. RESULTS: The difference in Fz began to increase significantly at 70°, while the difference in Ft became significant at 60°. When the angle was greater than 70°, there was no significant difference in the discrepancy between the actual and theoretical perforation points. Compared to judging the breakthrough point by CBCT, real-time force feedback TSFE under robotic surgery achieved more accurate initial breakthrough point detection. CONCLUSIONS: The smaller the angle, the larger the breakthrough force for the drill. The real-time force feedback of haptic robotic system during TSFE could provide reliable reference for dentists. More clinical studies are needed to further validate the application of robotic surgery assisted TSFE.

A Multivariate Logistic Regression Analysis of Risk Factors for Peri-implant Bone Loss.

OBJECTIVE: To evaluate multiple risk factors of peri-implant bone loss. MATERIALS AND METHODS: A case-control study was conducted on patients who had received dental implants treatment from January 2018 to December 2021. Implants with bone loss were included in the case group, and implants with no bone loss were included in the control group. Risk factors including history of periodontitis, abutment connection type, implant surface, diameter, location, three-dimensional position, opposing dentition, adjacent teeth, prosthetic type, retention type and custom abutment were evaluated. A multivariate logistic regression model was used to evaluate these risk factors, providing corresponding odds ratios (ORs) with 95% confidence intervals (CIs). RESULTS: A total of 776 implants in 479 patients were included in the analysis. The number of implants in the case group and the control group were 84 and 692, respectively. Cement-retained prostheses (OR=2.439, 95%CI=1.241-4.795) and nonplatform switch design (OR=2.055, 95%CI=1.167-3.619) were identified as weak risk factors. Horizontal deviation (OR=4.177, 95%CI=2.265-7.703) was a moderate risk factor. Vertical deviation (OR=10.107, 95%CI=5.280-19.347) and implants located in the mandibular molar region (OR=10.427, 95%CI=1.176-92.461) were considered high risk factors. CONCLUSION: Implants in the molar region, cement retained, non-platform switch design, and poor three-dimensional implant positioning are identified as significant risk factors for peri-implant bone loss.

Improved HPLC method with automated pre-column sample derivatisation for serum pegylated L-asparaginase activity measurement in paediatric acute lymphoblastic leukaemia patients.

Therapeutic drug monitoring of pegylated L-asparaginase (ASNase) ensures the drug effectiveness in childhood acute lymphoblastic leukaemia (ALL) patients. The biological drug property with variable immunogenic host clearance, and the prescription of its generic formulation urge the need for a reliable assay to ensure an optimal treatment and improve outcome. This study aimed to optimise an existing isocratic reversed-phase high performance liquid chromatography (RP-HPLC) method with an automated pre-column sample derivatisation and injection program, and a computational algorithm for measuring serum pegylated ASNase activity in children with ALL. Nath et al.'s method in 2009 was adopted and modified using a pegylated ASNase. A set of Microsoft Excel macros was developed for the serum drug activity computation. An Agilent InfinityLab LC Series 1260 Infinity II Quaternary System with fluorescence detection was employed with an Agilent Poroshell 120 EC-C18 4.6×100 mm, 2.7 µm analytical column. System flow rate was optimised to 2.0 mL/min with 40×10-6/bar pump compressibility. The O-phthaldialdehyde (OPA) solution composition was optimised to 1 % o-phthaldialdehyde, 0.8 % 2-mercaptoethanol, 7.13 % methanol, and 1.81 % sodium tetraborate. The pre-column derivatisation program mixed 0.1 µL sample with 25 µL OPA solution before the automated injection. Method validation was according to the ICH guidelines. Total analysis time was 15 min, with L-aspartic acid eluted at 0.96 min and internal standard at 4.7 min. The calibration curves showed excellent linearity (R ≥0.9999). Interday precision for the drug activity at 0.1 IU/mL, 0.5 IU/mL, and 1 IU/mL were 4.15 %, 3.05 %, and 3.09 % (n = 6). Mean %error for the drug activity at 0.1 IU/mL, 0.5 IU/mL, and 1 IU/mL were 0.90±4.41 %, -1.37±3.04 %, and -3.03±3.02 % (n = 6). Limit of quantitation was 0.03 IU/mL. Majority of the patients' serum drug activity fell within the assay calibration range. Our improved method is automated, having shorter analysis time with a well-maintained separation resolution that enables a high-throughput analysis for application.

[A quantitative study of mechanics in the treatment of atlantoaxial joint disorder by tendon relaxation manipulation].

OBJECTIVE: To explore dose-effect relationship of biomechanical parameters in treating atlantoaxial joint disorder by slimming manipulation. METHODS: From October 2022 to May 2023, 18 patients with atlantoaxial joint disorders were treated, including 10 males and 8 females;aged from 24 to 27 years old with an average of (25.50±1.10) years old;CT of cervical vertebra showed 16 patients with right side distortion and 2 patients with left side distortion. The mechanical parameters of treatment of atlantoaxial joint disorder by tendon relaxation manipulation were measured by wearing massage manipulation gloves. The magnitude, frequency and mechanical curve of force during tendon relaxation and starting force, pulling force, pulling time and mechanical curve during rehabilitation were quantified, the differences between the affected and contralateral manipulations were compared. RESULTS: The maximum force and frequency of Fengchi(GB20) on the affected side were (19.82±2.02) N and (116.83±14.49) times/min, and opposite side were (13.87±2.19) N and (188.89±16.03) times/min, respectively. There were statistically difference in the maximum force and frequency of both sides (P<0.05). The maximum force and frequency of Quepen (ST12) on the affected side were (14.44±3.27) N and (139.06±28.47) times/min, and those on the opposite side were (9.41±1.38) N and (142.50±28.47) times/min. There was difference in maximum force on both sides (P<0.05). The starting force, turning force and turning time of the affected side were (14.16±5.98) N, (11.56±6.63) N, (0.14±0.03) S, and the contralateral side were (8.94±3.39) N, (8.30±4.64) N, (0.18±0.04) S, respectively. The difference of starting force, turning force and turning time on both sides were statistically significant (P<0.05). CONCLUSION: By applying a light relaxation force on the affected side, the mechanical balance between cervical vertebrae could be restored, and recovery trend of atlantoaxial joint disorder could be strengthened. On this basis, the atlantoaxial odontoid process could be reversed by applying a light rotation force, which reflects the characteristics of high safety of the manipulation.

Midfacial Soft Tissue Recession Following Immediate Implant Placement with Bone Grafting in the Esthetic Area: A Systematic Review and Meta-analysis.

Purpose: To systematically analyze the outcomes of immediate implant placement (IIP) with bone grafting in the esthetic area. Materials and Methods: PubMed, Embase, and Cochrane CENTRAL were searched. Prospective studies reporting midfacial soft tissue recession (primary outcome) of single-tooth IIP with bone grafting in the esthetic area were included. Risks of bias were assessed. Meta-analysis, sensitivity analysis, and meta-regression were undertaken. Results: A total of 13 studies and 421 patients were included, with a follow-up length of 1 to 10 years in function. The weighted mean (95% CI) of midfacial soft tissue recession was 0.33 (0.21, 0.46) mm and 0.54 (0.16, 0.93) mm after 1 year and 5 years in function. Meta-regression indicated that after 1 year in function, there was 0.33 mm less midfacial soft tissue recession with soft tissue grafting (P = .021), while there was 0.58 mm more soft tissue recession (P = .007) in defect extraction sockets. Implant survival was 97.8%, and all failures were early failures. Peri-implant soft and hard tissue stability, peri-implant health, esthetic outcomes, and patient satisfaction were predictable within the follow-up period. Conclusion: Midfacial soft tissue recession showed an ongoing status in IIP with bone grafting in the esthetic area within 5 years in function. For extraction sockets with a thin gingival biotype or deficient buccal bone wall, soft tissue grafting was recommended.