Clinical utility of selected disease activity markers in patients with systemic lupus erythematosus

The objective of this study was to assess the utility of measurement of thrombomodulin, antinucleosome antibodies, sVCAM-1, sICAM-1, neopterin, fas ligand, IL-10 and sIL-2R in patients with systemic lupus erythematosus (SLE) and to compare them with traditional markers of SLE activity (anti-dsDNA antibodies, C3, C4) and the ECLAM index of disease activity. The measurement was performed over a 6-month period at three consecutive time points after 3 months in each of the 52 patients with SLE. Anti-dsDNA antibodies, thrombomodulin, antinucleosome antibodies, sVCAM-1m sICAM-1, neopterin, fas ligand, IL-10 and sIL-2R were tested by ELISA technique, while C3, C4 components of complement were tested by nephelometry. Fas ligand and IL-10 did not correlate with the ECLAM index. The rest of the markers showed significant correlation with the disease activity index. Thrombomodulin and anti-dsDNA antibodies reflect in the best way the changing trend in disease activity. Antinucleosome antibodies seem to be a promising marker useful in early diagnosis. Soluble VCAM-1, sICAM-1, neopterin and sIL-2R are interesting molecules with a role in disease pathogenesis, but their practical utility is limited. Received: 27 September 2000 / Accepted: 31 March 2001     

Post-gel shrinkage,elastic modulus,and stress generated by orthodontic adhesives

Objectives:To measure post-gel shrinkage, elastic modulus, and flexural strength of orthodontic adhesives and to predict shrinkage stress using finite element analysis (FEA).Materials and Methods:The following 6 orthodontic adhesives were tested: Transbond XT (3M Unitek, Monrovia, Calif), Transbond Plus Color Change (3M Unitek), Greengloo (Ormco, Brea, Calif), Ortho Connect (GC America, Alsip, Ill), Trulock (RMO, Denver, Colo), GoTo (Reliance, Itasca, Ill). Post-gel shrinkage was measured using a biaxial strain gauge during light curing. Elastic modulus and flexural strength were measured with a 4-point bending test. Analysis of variance and Student-Newman-Keuls post hoc tests were used to compare the shrinkage, elastic modulus, and flexural strengths among the materials (α = .05). Shrinkage stresses caused by the post-gel shrinkage and elastic modulus values were calculated using a cross-sectional FEA of a metallic bracket bonded to an incisor.Results:Properties were highly different among the adhesives (P ≤ .0001). Transbond XT (0.38 ± 0.09 percent volumetric contraction) and GoTo (0.42 ± 0.05 percent volumetric contraction) had the lowest post-gel shrinkage; Transbond Plus Color Change had the highest (0.84 ± 0.08 percent volumetric contraction). OrthoConnect (6.8 ± 0.6 gigapascals) had the lowest elastic modulus; GoTo (28.3 ± 3.1 gigapascals) had the highest. Trulock (64.1 ± 8.2 megapascals) had the lowest flexural strength; Greengloo (139.1 ± 20.7 megapascals) had the highest. FEA showed that the highest shrinkage stresses were generated with Transbond Plus Color Change and the lowest with OrthoConnect.Conclusions:Post-gel shrinkage of orthodontic adhesives was comparable with restorative composites, which are known to create shrinkage stresses in restored teeth. FEA indicated that this shrinkage creates stresses in the adhesive and in the enamel around the brackets.     

Tube Technique with Light-curing Composite for Removing Fractured Root Canal Instruments: Influence of Polymerization Cycles and Mechanical Exposure

IntroductionThe purpose of this study was to investigate the influence of both polymerization cycles and mechanical exposure procedures on the adhesion of instrument fragments using a modified tube technique with a light-curing composite.MethodsEighty Mtwo instruments (size 15.05; VDW, Munich, Germany) were cut at a diameter of 35/100 mm and clamped in a vice with an overlap of 2 mm. Matching cannulas were filled with SDR composite (Dentsply, York, PA) and placed over the instruments. Prime & Bond Active (Dentsply Sirona, Bensheim, Germany) was used as the bonding material. Glass fiber was inserted from the opposite side into the cannula, and 1, 2, 4, or 6 polymerization cycles of 30 seconds were applied (800 mW/mm²) (n = 20/group). Sixty further identical instruments (n = 20/group) were divided into the following groups: group 1, cut at 10 mm and left unprepared (taper = 5%); group 2, parallelized using diamond instruments (taper = 0%); and group 3, prepared in a way that an inverted conical taper resulted (taper = 2%). Polymerization was performed for 2 minutes. The failure load and mode of failure were determined using a tensile testing device (2 mm/min). Data were statistically analyzed using the Kruskal-Wallis or chi-square test.ResultsThe failure load increased significantly with the number of polymerization cycles (P < .0001). More than 4 polymerization cycles had no further benefit (P > .05). The failure load in the inverted conical group was significantly lower (P < .0001) compared with the parallel and the unprepared groups. Adhesive failure was significantly more frequent in groups 2 and 3 (20/20) than in group 1 (16/20) (P < .05).ConclusionsBoth the number of polymerization cycles and the mechanical exposure procedures had a significant impact on the adhesive force when using the tube technique.     

双侧唇腭裂新生儿数字化模型与硬石膏模型的比较

目的： 比较双侧唇腭裂新生儿口内扫描数字化模型和硅橡胶制取灌注的超硬石膏模型的可靠性和稳定性。方法： 收集19例双侧唇腭裂新生儿病例,分别制取口内扫描数字化模型和硅橡胶取模超硬石膏灌注模型,对上颌牙槽骨长度、上颌牙槽骨宽度、腭裂宽度及上颌中线偏斜量等指标进行测量。采用SPSS 24.0软件包对测量结果进行统计学分析。结果： 2种方法上颌牙槽骨长度、上颌牙槽骨宽度、腭裂宽度及上颌中线偏斜量3次测量间均无统计学差异（P>0.05）,2种方法的测量值无统计学差异（P>0.05）。结论： 双侧唇腭裂新生儿口内扫描获取的数字化模型与硅橡胶取模超硬石膏灌注获取的石膏模型各测量项目之间无显著差异。口内数字化扫描操作过程简便,可以提高诊疗效率,新生儿承受痛苦少,风险小,可广泛用于唇腭裂患儿的研究、诊断分析及临床治疗。     

Adhesion procedures for CAD/CAM indirect resin composite block: A new resin primer versus a conventional silanizing agent

PurposeThe purpose of this study was to evaluate the effectiveness of both a resin primer containing methyl methacrylate (MMA) and a silanizing agent on bonding to indirect resin composite blocks, using two types of build-up hybrid resin composites.MethodsSHOFU BLOCK HC (Shofu) specimens were blasted with alumina, after which one of two surface treatments was applied: CERA RESIN BOND (Shofu, the Silane group) or HC primer (Shofu, the MMA group). Resin composites made using either Solidex Hardura (SDH, Shofu) or Ceramage Duo (CMD, Shofu) were built up and micro-tensile bond strength (μTBS) values were measured after storage in water for either 24 h or 6 months (n = 24 per group). The fracture surfaces after μTBS measurements and the resin block/build-up resin interfaces were observed by scanning electron microscopy (SEM).ResultsThe bond strength of the Silane/SDH group significantly decreased after 6 months (p < 0.001), whereas in the MMA group there was no significant loss after 24 h or 6 months (p = 0.99). In the CMD group, the bond strength after 6 months was significantly lowered in both the Silane group (p < 0.001) and the MMA group (p < 0.001), but the latter still showed greater adhesion. SEM images demonstrated that the matrix resin was partially destroyed at the fracture surfaces of the MMA group and fracture surface unevenness was observed.ConclusionsA primer containing MMA produced stronger bonding to CAD/CAM resin even after long-term aging compared to a silane treatment.     

Positional factors affecting the bond failure rates in orthodontic treatment: A systematic review and meta-analysis

PurposeThe purpose of this study was to make a systematic review and meta-analysis of studies investigated the effects of positional factors on the bonding failure of brackets.MethodsElectronic databases (PubMed, Web of science, Scopus) were searched by 3 independent researchers. Randomized studies comparing maxilla-mandibular region, anterior–posterior segments, and right-left arch were included in the meta-analysis. The odds ratio was used as the effect size. A two-tailed test was performed to compare the factors. Heterogeneity was calculated with the Cochran Q test and I² statistics.ResultsAssociation was found between bonding failure and dental regions (OR = 1.24, 95% CI: 1.05, 1.46) (p = 0.009) and between bonding failure and anterior–posterior segments, too (OR = 1.96, 95% CI: 1.58, 2.45) (p < 0.001). But, no association was found bonding failure and arch sides (OR = 1.11, 95% CI: 0.96, 1.29) (p = 0.26).ConclusionClinicians should more care, especially when operating in the mandibular region and posterior segment. However, there is no difference between the left and right arch in terms of the loss of the bracket.     

A comparative assessment of bracket survival and adhesive removal time using flash-free or conventional adhesive for orthodontic bracket bonding: A split-mouth randomized controlled clinical trial

Objectives:To compare bracket survival and adhesive removal time between a flash-free and a conventional adhesive for orthodontic bracket bonding.Materials and Methods:Forty-five consecutive patients had their maxillary incisors, canines, and premolars bonded with ceramic brackets using a flash-free adhesive (APC Flash-Free Adhesive, 3M Unitek, Monrovia, Calif) on one side and a conventional adhesive (APCII Adhesive, 3M Unitek) on the other side. The side allocation was randomized. Bracket failure was recorded at 4-week intervals. The adhesive remnant index (ARI) was scored on debond and adhesive removal timed to the nearest second. The primary outcome was adhesive removal time per quadrant. Secondary outcomes were bracket failure rate, time to first-time failure of a bracket, and ARI score on debond. Paired t-tests were used to compare adhesive removal times and ARI scores between the adhesives with P < .05 considered statistically significant.Results:Bracket failure rates were 4.3% for the flash-free adhesive and 1.9% for the conventional adhesive, with mean times to first-time failure of 31 weeks for the flash-free adhesive and 42 weeks for the conventional adhesive; neither failure rates nor times to first failure were significantly different. Although the flash-free adhesive left significantly more adhesive on the tooth surface after debonding, the adhesive removal times were 22.2% shorter than with the conventional adhesive.Conclusions:Bracket survival with the flash-free adhesive was equivalent to the conventional adhesive when ceramic brackets were bonded. Adhesive removal was significantly faster when using the flash-free adhesive, which may result in time savings of more than 20% compared with the conventional adhesive.     

An In Vitro Evaluation of the Microleakage under Complete Metal Crowns Using Three Adhesive Luting Cements

Despite the material advancements and precise laboratory techniques, cement lines are inevitable in fixed prosthodontics which leads to increased dependence on the integrity of the cement to maintain the marginal seal. The material class of luting agent is known to influence microleakage. Studies of cement dissolution and disintegration have produced varying results. Hence, this study was done to evaluate marginal leakage under complete metal crowns using three adhesive cements, two resin cements (one self cure, one dual cure) and a glass ionomer cement. Metal crowns were prepared on sixty intact extracted premolars and were randomly divided into three groups of twenty each, with each group using a different cement for luting. All the samples were then subjected to thermocycling and were sectioned using a diamond saw. Reflected Binocular Stereomicroscope at 100× magnification was used to study the extent of microleakage at both metal cement (MC) and tooth cement (TC) interface, at two opposite margins of each sectioned specimen. Data was analyzed with a one way analysis of variance. For comparison among the groups multiple comparison Bonferroni test was done. Within group data was analysed with independent student t test. Between three groups, metal crowns cemented with multilink cement showed significantly less microleakage at both the interfaces. Glass ionomer cement recorded maximum combined microleakage amongst three cements irrespective of the interfaces. Within group, glass ionomer and multilink cement showed more microleakage at MC interfaces than at TC interface. A complex interaction between variables related to dental restoration, luting agent and tooth structure probably influence microleakage. In vitro studies must always be followed by in vivo studies before definite conclusion can be drawn.     

Effect of application mode on interfacial morphology and chemistry between dentine and self-etch adhesives

Objective

To investigate the influence of application mode on the interfacial morphology and chemistry between dentine and self-etch adhesives with different aggressiveness.

Methods

The occlusal one-third of the crown was removed from un-erupted human third molars, followed by abrading with 600 grit SiC under water. Rectangular dentine slabs were prepared by sectioning the tooth specimens perpendicular to the abraded surfaces. The obtained dentine slabs were treated with one of the two one-step self-etch adhesives: Adper Easy Bond (AEB, pH ∼ 2.5) and Adper Prompt L-Pop (APLP, pH ∼ 0.8) with (15 s, active application) or without (15 s, inactive application) agitation. The dentine slabs were fractured and the exposed adhesive/dentine (A/D) interfaces were examined with micro-Raman spectroscopy and scanning electron microscopy (SEM).

Results

The interfacial morphology, degree of dentine demineralization (DD) and degree of conversion (DC) of the strong self-etch adhesive APLP showed more significant dependence on the application mode than the mild AEB. APLP exhibited inferior bonding at the A/D interface if applied without agitation, evidenced by debonding from the dentine substrate. The DDs and DCs of the APLP with agitation were higher than those of without agitation in the interface, in contrast to the comparable DD and DC values of two AEB specimen groups with different application modes. Raman spectral analysis revealed the important role of chemical interaction between acid monomers of self-etch adhesives and dentine in the above observations.

Conclusion

The chemical interaction with dentine is especially important for improving the DC of the strong self-etching adhesive at the A/D interface. Agitation could benefit polymerization efficacy of the strong self-etch adhesive through enhancing the chemical interaction with tooth substrate.