耳脑医用粘合剂修补脑脊液漏

耳脑医用粘合剂是α－氰基丙烯酸正辛酯和α－氰基丙烯酸正丁酯及少量添加剂配伍而成的复合性医用粘合剂。应用此粘合剂粘合修补脑脊液漏２７例，其中外伤性脑脊液鼻漏５例，经鼻蝶入路垂体瘤切除术脑脊液漏６例，开颅手术后手术切口脑脊液漏１１例，脊膜膨出修补术后脑脊液漏５例。成功２５例，成功率９３％。应用此粘合剂修补脑脊液漏具有简便、迅速、有效的特点。     

Structure and properties of methacrylate based dental restorative materials

The chemistry and structure of the dimethacrylate resins and the nature of the filler systems in dental composite resins are reviewed in relation to their influence on the setting behaviour, dimensional stability, aesthetics, fracture behaviour and adhesive potential. It is clear that a deeper understanding of the structure of the polymeric matrix and the mechanism of clinical wear is required. As a result of ongoing research in this area and with the development of dentine adhesives, the future prospects of composite resins are encouraging.     

自酸蚀牙本质粘接剂对人牙髓成纤维细胞的毒性作用

目的比较和评价自酸蚀粘接剂XenoⅢ（XO）和Adper Prompt（AP）以及全酸蚀粘接剂Single bond2（SB）三者的细胞毒性大小。方法将3种牙本质粘接剂XO、AP和SB涂布于直径为5.0 mm、厚度为0.5 mm的牙本质圆片的两面,置于DMEM培养液中获得材料的浸提液,然后将培养液稀释成100.0%、50.0%、25.0%和12.5%四种体积分数。选用组织块法体外原代培养人牙髓成纤维细胞,并将不同体积分数的材料浸提液与第5代人牙髓成纤维细胞共同培养,通过MTT法评价材料24、72、120 h的细胞毒性。结果牙本质粘接系统XO、AP和SB在体外对人牙髓成纤维细胞均有一定程度的细胞毒性,两种自酸蚀粘接剂XO和AP的细胞毒性明显低于全酸蚀粘接剂SB,其差异有统计学意义（P<0.05）。结论自酸蚀牙本质粘接剂XO和AP的细胞毒性小于全酸蚀牙本质粘接剂SB。     

Intensity and duration of in‐vitro antibacterial activity of different adhesives used in orthodontics

This work investigated the antibacterial activity of 14 bonding agents to predict their ability to inhibit white‐spot development during orthodontic treatment. Standardized, sterilized disks of each material were continuously rinsed (for up to 180 d) in a flow of sterile saline. At predetermined time points, the residual ability of each material to inhibit bacterial growth (determined by measuring the size of inhibition halos around disks placed onto appropriate culture media seeded with Streptococcus gordonii DSM6777, Streptococcus sanguinis DSM20567, Streptococcus mutans DSM20523, or Lactobacillus acidophilus DSM20079) and biofilm formation (determined by measuring the numbers of bacteria adherent to disks following incubation in appropriate broths) was tested in triplicate and compared with the baseline activities of freshly prepared materials. Overall antibacterial and anti‐biofilm activities, adjusted for exposure time and strain of bacteria, were assessed. The decrease of antibacterial activity was faster (30–60 d) and complete for fluoride‐enriched materials, but slower (90 d) and partial for antimicrobial‐containing materials (benzalkonium chloride, zinc oxide, chlorexidine, or MDPB). Materials enriched with benzalkonium chloride, chlorexidine, or MDPB showed the highest antibacterial activities. Anti‐biofilm assays yielded similar results. These data could be helpful for clinicians in the choice of the best performing bonding agent also in light of duration of the clinical application.     

The effect of universal adhesives on dentine collagen

ObjectivesThe purpose of the study was to evaluate the integrity of dentine type I collagen after self-etching (SE) treatments with strong and mild universal adhesives.MethodsCoronal dentine specimens (n = 10/product) were imaged by optical microscopy and analyzed by ATR-FTIR spectroscopy before and after treatment with 32% phosphoric acid gel (PA-negative control), 17% neutral EDTA (ED-positive control) conditioners and Adhese Universal (AD), Clearfil Universal Bond Quick (CQ), G-Premio Bond (GP), Prelude One (PR) and Scotchbond Universal (SB) adhesives. From the spectroscopic analysis the following parameters were determined: a) Extent of dentine demineralization (DM%) and b) percentage area of the Amide I curve-fitted components of β-turns, 3₁₀-helix/β-turns, α-helix, random coils, β-sheets and collagen maturation (R) index. Statistical analysis was performed by one-way ANOVA (DM%), paired t-test/Wilcoxon test (Amide I components) and Spearman correlation coefficient (DM% vs Amide I components) at an a = 0.05 level.ResultsPA, ED and GP removed the smear-layer and opened tubule orifices, whereas all other treatments removed only the intratubular smear-layer fraction. The ranking of the statistically significant differences in DM% was PA > GP > ED > AD, SB, CQ, PR, with AD being significantly different from PR. Regarding the Amide I components, PA demonstrated a significant reduction in β-turns, α-helices and an increase in β-sheets, GP a reduction in β-turns, AD an increase in β-turns and random coils, and CQ an increase in β-turns. PR, SB and ED showed insignificant differences in all the Amide I components. Significant correlations were found between DM%-random coils and DM%-R.SignificanceThe universal adhesives used in the SE mode induced none to minimal changes in dentine collagen structure, without evidence of the destabilization pattern observed after conventional phosphoric acid treatments.     

Safety and Usability of Hemostats,Sealants, and Adhesives

Hemostats, sealants, and adhesives are an integral part of surgical patient care. Nurses who have knowledge about these agents can better help ensure safe, efficient surgical patient care. As a caregiver and patient advocate, the perioperative nurse must understand the most current information about these agents and be prepared to facilitate the transfer of this knowledge to all caregivers. Information about these agents, including the contraindications, warnings, and precautions associated with their use as well as their preparation and application, is provided here. Algorithms designed to clarify the best options for using hemostats, sealants, and adhesives are included as well.     

Experimental study of brackets adhesion with a novel enamel-protective material compared with conventional etching

IntroductionA reliable adhesion between fixed devices and dental surfaces is a key factor for the clinical success of any orthodontic treatment. Adhesion preparation is associated with damages related to abrasive cleaning, enamel structure defacing caused by etching, enamel loss when removing resin remnants at orthodontic treatment finishing stage or when conditioning surface for adhesive failure and fractures at bracket removal.AimThe objective of this study was to compare the shear bond strength of metallic brackets to enamel adhered with a novel non-damaging and remineralizing material for enamel versus the traditional 37% phosphoric acid etching.Material and methods75 Premolars collected from 15- to 40-years old healthy donors requiring extraction were collected. The teeth were then randomly divided into three groups (n = 25). One group was used for the experimental new method (EX), the second for the conventional phosphoric acid etching (PA) method and the third group was left without any treatment (NT). The metallic brackets were fixed with Transbond® XT adhesive and composite resin polymerized for 40 s with a halogen photocuring lamp. The shear bond strength was quantified by means of a universal testing machine at 1 mm/min crosshead speed and a load cell of 1 kN.Statistical analysis usedTests of normality, adjustment of the data to a root square, a one-way ANOVA and Tukey tests were performed.ResultsStatistically significant differences between the NT (1.4 MPa), PA (32.1 MPa) and EX (9.7 MPa) groups were observed.ConclusionsThe experimental material for conditioning human enamel induces calcium phosphates crystals on the enamel surface and improves the bond strength in comparison to the NT group.     

Effect of a functional monomer (MDP) on the enamel bond durability of single‐step self‐etch adhesives

The present study aimed to determine the effect of the functional monomer, 10‐methacryloxydecyl dihydrogen phosphate (MDP), on the enamel bond durability of single‐step self‐etch adhesives through integrating fatigue testing and long‐term water storage. An MDP‐containing self‐etch adhesive, Clearfil Bond SE ONE (SE), and an experimental adhesive, MDP‐free (MF), which comprised the same ingredients as SE apart from MDP, were used. Shear bond strength (SBS) and shear fatigue strength (SFS) were measured with or without phosphoric acid pre‐etching. The specimens were stored in distilled water for 24 h, 6 months, or 1 yr. Although similar SBS and SFS values were obtained for SE with pre‐etching and for MF after 24 h of storage in distilled water, SE with pre‐etching showed higher SBS and SFS values than MF after storage in water for 6 months or 1 yr. Regardless of the pre‐etching procedure, SE showed higher SBS and SFS values after 6 months of storage in distilled water than after 24 h or 1 yr. To conclude, MDP might play an important role in enhancing not only bond strength but also bond durability with respect to repeated subcritical loading after long‐term water storage.     

A prospective,multi-center,practice-based cohort study on all-ceramic crowns

ObjectivesThe aim of this prospective, multi-center, practice-based cohort study was to analyze factors associated with the success of all-ceramic crowns.MethodsAll-ceramic crowns placed in a practice-based research network ([Ceramic Success Analysis, AG Keramik) were analyzed. Data from 1254 patients with (mostly in-office CAD/CAM) all-ceramic crowns placed by 101 dentists being followed up for more than 5 years were evaluated. At the last follow-up visit crowns were considered as successful (not failed) if they were sufficient, whereas crowns were considered as survived (not lost) if they were still in function. Multi-level Cox proportional hazards models were used to evaluate the association between a range of predictors and time of success or survival.ResultsWithin a mean follow-up period (SD) of 7.2(2)years [maximum:15years] 776 crowns were considered successful (annual failure rate[AFR]:8.4%) and 1041 crowns survived (AFR:4.9%). The presence of a post in endodontically treated teeth resulted in a risk for failure 2.7 times lower than that of restorations without a post (95%CI:1.4–5.0;p = 0.002). Regarding the restorative material and adhesive technique, hybrid composite ceramics and single-step adhesives showed a 3.4 and 2.2 times higher failure rate than feldspathic porcelain and multi-step adhesives, respectively (p < 0.001). Use of an oxygen-blocking gel as well as an EVA instrument resulted in a 1.5–1.8 times higher failure rate than their non-use (p ≤ 0.001).SignificanceAfter up to 15years AFR were rather high for all-ceramic crowns. Operative factors, but no patient- or tooth-level factors were significantly associated with failure.The study was registered in the German Clinical Trials Register (DRKS-ID: DRKS00020271).