[Prediction, analysis and application of learning curve of tooth preparation for all ceramic crowns of maxillary central incisors].

OBJECTIVE: To predict the learning curve of tooth preparation for all ceramic crowns of maxillary central incisors on phantom head simulators for graduate students participating in standardized dental resident training based on the modified Wright learning curve model, then to analyze and applicate the learning curve. METHODS: Twelve graduate students participating in standardized dental resident training were selected to prepare the resin maxillary central incisors on phantom head simulators for all ceramic crowns 4 times. The results of preparation were evaluated by 3 prosthetic experts with at least 10 years' experience focusing on the reduction, contour, taper, shoulder, finish line, margin placement, adjacent tooth injury, and preparation time for tooth preparation. The learning rate of tooth preparation was calculated by scores of tooth preparation of 4 times. The learning curve of tooth preparation was predicted based on the modified Wright learning curve model. According to the criteria of standardized training skill examinations for dental residents in Beijing, 80 was taken as the qualified standard score. The minimum training times for tooth preparation to satisfy the qualified standard score (80) was calculated, to analyze the characteristics of learning curve and evaluate the effectiveness of tooth preparation. RESULTS: The scores of 4 tooth preparation were 64.03±7.80, 71.40±6.13, 74.33±5.96, and 75.98±4.52, respectively. The learning rate was (106±4)%, which showed the learning curve an upward trend. There were no significant differences between the qualified standard score and the predicted scores of tooth preparation from the 5th preparation to the 13th preparation (P > 0.05). The predicted score of the 14th preparation was higher than the qualified standard score (P < 0.05). CONCLUSION: The trend of the learning curve of tooth preparation for all ceramic crowns of maxillary central incisors on phantom head simulators for graduate students participating in standardized dental resident training is upward, which predicts the minimum training times higher than the qualified standard score is 14 times.

The role of muscarinic acetylcholine receptor type 3 polypeptide (M3RP205-220) antibody in the saliva of patients with primary Sjögren's syndrome.

BACKGROUND: Sjögren's syndrome (SS) is a chronic autoimmune disorder of unknown cause. Recent studies have shown that antimuscarinic acetylcholine type 3 receptor (M3R) antibodies can be detected in patients with Sjögren's syndrome (SS), but little is known about the diagnostic value of this antibody. OBJECTIVES: To assess the clinical correlations of anti-M3R (muscarinic acetylcholine receptor type 3) polypeptide (M3RP205-220) antibodies in saliva from patients of primary Sjögren's syndrome (pSS). METHODS: Serum samples and unstimulated mixed saliva from 100 patients with SS were collected and examined. Their mean (SD) age was 54.2 (13.4) years, and the mean (SD) disease duration was 6.2 (3.8) years. Serum samples from 40 patients with systemic lupus erythematosus (SLE), 40 with rheumatoid arthritis (RA), and 60 healthy subjects were analysed as controls. All the patients with SS were carefully evaluated according to European and American criteria. A circular M3RP205-220 peptide sequence was synthesized using solid-phase techniques on an applied biosytems peptide synthesizer. The correlation between anti-M3RP205-220 antibodies and clinical manifestations of pSS was analysed. RESULTS: The IgG of anti-M3RP205-220 antibodies was present in 69% of patients with pSS, 27.5% with SLE, 22.5% with RA, and 23.3% of normal saliva donors. The prevalence of anti-M3RP205-220 antibodies in pSS was significantly higher than in SLE, RA, and normal controls. The specificity of anti-M3RP205-220 antibodies in pSS was 75%. The salivary flow rate in the group positive for anti-M3RP205-220 was 436 µl/10 min, compared to a rate of 658 µl/10 min for the negative group (p<0.05). CONCLUSIONS: The anti-M3RP205-220 antibody was detected in most patients with pSS. The presence of the antibody was closely associated with the salivary flow rate. This indicated that it may act as an autoantigen, with a role in the pathogenesis of pSS.

A comparative study of transfection efficiency between liposomes, immunoliposomes and brain-specific immunoliposomes.

This study investigated the transfection ability and efficiency of liposomes and immunoliposomes for exogenous gene delivery into the brain via the venous system. Four groups of rats underwent tail vein injection with one of the following: liposomes encapsulating pCMV (human cytomegalovirus promoter)-LacZ plasmid 80 microg (low dose) or 300 microg (high dose); general immunoliposomes encapsulating 80 microg transferrin receptor antibodies (OX26)-pCMV-LacZ plasmid; or brain-specific immunoliposomes encapsulating 80 microg OX26-pGFAP (glial fibrillary acidic protein promoter)-LacZ plasmid. A control group received no injected agent. The LacZ mRNA levels (1 h post-injection) and beta-galactosidase activity (48 h post-injection) in the brain and peripheral organs were assayed using real-time reverse transcription-polymerase chain reaction and histochemical staining, respectively. Both immunoliposomes delivered exogenous DNA containing the LacZ gene into the brain after venous injection, resulting in extensive LacZ expression in the brain. Furthermore, the brain-specific OX26-pGFAP-LacZ immunoliposome decreased the non-specific expression of LacZ in peripheral organs without affecting transfection efficiency in the brain. Thus, brain-specific immunoliposomes are an efficient and brain-specific targeting vector.

[Discussion on teaching reform of oral histopathology in multiple classes].

In the information age, teaching methods are undergoing tremendous changes, and the traditional teaching methods are difficult to draw students' attention. As the core course of stomatology, oral histopathology is an important foundation for oral students. Along with the rapid development of medical science, it is imperative to deepen the reform of teaching. This article discussed the diversified teaching methods conducted in oral histopathology course in Zhejiang University School of Stomatology in the past 10 years with the core teaching theory of "learning before teaching" including the exploration design course, case based learning, journal club, etc. Diversified teaching methods activated students' subjective initiative, which laid a foundation for the next stage of clinical study, and provided a guiding framework for the future teaching reforms.

Immunohistochemical and in-situ hybridization study of hypoxia inducible factor-1alpha and angiopoietin-1 in a rabbit model of mandibular distraction osteogenesis.

The endogenous release of angiogenic factors in a rabbit mandibular distraction osteogenesis model was investigated. The spatial and temporal expression of hypoxia inducible factor-1alpha (HIF-1alpha) and angiopoietin-1 (Ang-1) was compared at different phases. The lengthened calluses were harvested on post-osteotomy days 13, 20, 34 and 48, and then stained with haematoxylin & eosin. Immunohistochemical (IHC) and in-situ hybridization (ISH) examination of HIF-1alpha and Ang-1 staining was performed. The ossification in the distracted gap was predominantly intramembranous and slightly endochondral. Expression of HIF-1alpha and Ang-1 was mainly detected in the cytoplasm of fibroblast-like cells, osteoblasts and immature osteocytes on day 13 and 20, but declined with bone maturation. HIF-1alpha was also detected in the nuclei of some osteoblasts. These results suggest that the production of HIF-1alpha and Ang-1 in the distracted gap may contribute to new bone formation during gradual distraction of the mandible.

[Clinical applications of transcrestal around detached sinus floor elevation technique using osteotomes and sequential drills with stops].

Sinus floor elevation was needed in 11 patients having 15 implant sites with the residual bone height (RBH) was less than 10 mm in the posterior maxillary region from Feb to May 2017. The RBH ranged from 3.10 to 8.34 mm [averaged (6.18±1.60) mm]. RBH<6 mm was observed in 40% implant sites (6 implant sites) and RBH≥6 mm was observed in 60% implant sites (9 implant sites). The thickness of the sinus floor membrane correspond to the implant site measured by cone beam CT (CBCT) ranged from 0.50 to 4.24 mm [averaged (1.21±0.92) mm]. Sequential drills with stops were used to perforate the cortical bone of the sinus floor firstly, then the transcrestal around detached sinus floor elevation technique (TADSFET) was carried with osteotomes. Anorganic bovine bone was used as the augmentation material.Fifteen implants were placed in 15 implant sites. CBCT pictures showed that there was a smooth and continuous tent-shaped apophysis on each lifted site and no air fluid level was observed in the sinus immediately after operation. The mean elevated height of the 15 implant sites was (7.83±1.57) mm (ranged from 5.94 to 11.01 mm). The mean follow-up time was 7.91 months (7-10 months). The survival rate was 100% during the follow up period.

Early bone response to sandblasted, dual acid-etched and H2O2/HCl treated titanium implants: an experimental study in the rabbit.

The aim of this study was to evaluate the influence of a roughened H(2)O(2)/HCl heat-treated titanium surface on peri-implant bone formation at an early stage in vivo. 24 Ti(6)Al(4)V alloy implants were used; half were treated by sandblasted and dual acid-etched treatments (control group), while the others were treated by sandblasted, dual acid-etched and H(2)O(2)/HCl heat treatments (test group). The morphology and roughness were analyzed by field emission SEM and atomic force microscopy. The implants were inserted into the femora of 12 adult white rabbits. After 2 and 4 weeks, femora block specimens were prepared for histological and histomorphometric analysis. SEM micrographs showed that multilevel and different sized pits were formed on both surfaces. New bone formation was observed on both implant surfaces. Test implants demonstrated a greater mean percentage of bone-implant contact as compared with controls at 2 (46.84 vs. 41.81, p=0.000) and 4 weeks (49.43 vs. 44.87, p=0.006) of healing. It is concluded that the H(2)O(2)/HCl heat-treated rough titanium surface promoted enhanced bone apposition during the early stages of new bone formation around the implant.

Schistosoma mansoni: characterization of phosphoinositide response.

Signal transduction pathways may have important regulatory roles in cellular events in the human parasite Schistosoma mansoni. The presence of the phosphoinositide response in S. mansoni was examined by radiolabeling intact worms with 20 muCi of [3H]myoinositol for 24 hr and stimulating parasites with 25 mM NaF and 10 microM AlCl3 in the presence of 10 mM LiCl. Total inositol phosphates were increased within 2 min and maximal accumulation was achieved after 30 min. Similar results were seen with the non-hydrolyzable GTP analogues GTP gamma S and GppNHp while only minimal changes were detected with GMP. Neomycin inhibited NaF-induced inositol phosphate production. NaF stimulated a significant 3.6-fold increase of inositol phosphates in females compared to males. These data suggest that stimulation of guanine nucleotide-binding regulatory proteins activates phospholipase C resulting in production of inositol phosphates in S. mansoni.