Evaluation of a Technique for Reducing Chairside Occlusal Adjustment of Crowns.


  • 影响因子:1.81
  • DOI:10.1111/jopr.13252
  • 作者列表:"Altarakemah Y","Akbar J","Akthar S","Qudeimat MA","Omar R
  • 发表时间:2021-02-01

PURPOSE:To assess whether the occlusion of metal-ceramic crowns, as received from the laboratory, and the time taken to adjust the occlusion of crowns not deemed acceptable, can be reduced by fabricating the crowns with controlled amounts of infra-occlusion during the laboratory phase. MATERIAL AND METHODS:An opposing set of typodonts, articulated in maximum intercuspal position served as the patient in an in vitro simulation. Seventy-five metal-ceramic crowns were fabricated for the mandibular right second molar with three different occlusal contact specifications: A, control group had occlusal contacts shared evenly by the crown and the neighboring teeth (n = 25); B, first experimental group had the occlusion relieved until 2 shimstock foils were able to be pulled from between the crown and the opposing tooth without tugging (n = 25); C, second experimental group had the occlusion relieved until 4 shimstock foils were able to be pulled from between the crown and the opposing tooth without tugging (n = 25). The occlusion of each crown, as received from the laboratory, was assessed using one of three categories (Excellent, Acceptable, and Poor). Chi-square analysis was used to test the differences in occlusal outcomes between the three study groups. For all of those rated "Acceptable," the time taken to adjust each crown to proper occlusion was recorded. One-way analysis of variance (ANOVA) and Bonferroni tests were carried out to compare the adjustment times across the three study groups. RESULTS:The 2-shim group had the best outcome, with 56% of the crowns rated as "Excellent" (p = 0.001). In addition, there were statistically significant differences in adjustment times between the control group (A) and the 2-shim (B) and the 4-shim (C) groups (p = 0.0001), but not between the 2-shim (B) and 4-shim (C) groups (p = 0.08). CONCLUSIONS:Metal-ceramic crowns fabricated with controlled interocclusal relief of 2- and 4-shims each required less time for chairside occlusal adjustment than crowns fabricated in the laboratory to conventional occlusal contact. However, the overall superior outcome, in terms of the possibility for immediate insertion as received from the laboratory as well as favorable chairside adjustment time, for the 2-shim prespacing suggests that this dimension is the preferred option over 4-shim prespacing to reduce occlusal inaccuracies of indirect restorations.


目的: 评估从实验室收到的金属陶瓷冠的闭塞,以及调整冠的闭塞所花费的时间是否被认为是不可接受的,是否可以通过在实验室阶段制造具有受控量的下闭塞的冠来减少。 材料和方法: 在体外模拟中作为患者使用在最大cuspal位置铰接的相对组的typodonts。为下颌右第二磨牙制作了75个金属烤瓷冠,有三种不同的咬合接触规格: A、对照组牙冠与邻牙均匀共用咬合接触 (n = 25); B、第一个实验组解除咬合,直到2个咬合箔能够从牙冠和相对牙齿之间拔出而不拖拉 (n = 25); C,第二个实验组解除咬合,直到4个咬合箔能够从牙冠和相对牙齿之间拔出而不拖拉(n = 25)。使用三个类别 (优秀、可接受和差) 之一评估从实验室接收的每个牙冠的咬合。卡方分析用于测试三个研究组之间咬合结果的差异。对于所有评级为 “可接受” 的那些,记录调整每个牙冠至适当咬合所花费的时间。进行单向方差分析 (ANOVA) 和Bonferroni检验以比较三个研究组的调整时间。 结果: 2-shim组效果最好,56% 的冠被评为 “优秀” (p = 0.001)。此外,对照组 (A) 和2-shim (B) 和4-shim (C) 组之间的调整时间差异有统计学意义 (p = 0.0001),但2-shim (B) 和4-shim (C) 之间没有差异组 (p = 0.08)。 结论: 与实验室制造的牙冠相比,用2-和4-垫片的受控咬合间缓解制造的金属陶瓷牙冠相对于传统咬合接触而言,椅侧咬合调整所需的时间较少。然而,就从实验室获得的立即插入的可能性以及有利的椅侧调整时间而言,2-垫片预起搏的总体优异结果表明,与4-垫片预起搏相比,该尺寸是减少间接修复的咬合不准确性的首选选项。

关键词: 皇冠 遮挡 时间


作者列表:["Juan-Carlos PM","Perla-Lidia PP","Stephanie-Talia MM","Mónica-Griselda AM","Luz-María TE"]

METHODS::The ATP binding-cassette superfamily corresponds the mostly transmembrane transporters family found in humans. These proteins actively transport endogenous and exogenous substrates through biological membranes in body tissues, so they have an important role in the regulation of many physiological functions necessary for human homeostasis, as well as in response regulation to several pharmacological substrates. The development of multidrug resistance has become one of the main troubles in conventional chemotherapy in different illnesses including cancer, being the increased efflux of antineoplastic drugs the main reason for this multidrug resistance, with a key role of the ABC superfamily. Likely, the interindividual variability in the pharmacological response among patients is well known, and may be due to intrinsically factors of the disease, genetic and environmental ones. Thus, the understanding of this variability, especially the genetic variability associated with the efficacy and toxicity of drugs, can provide a safer and more effective pharmacological treatment, so ABC genes are considered as important regulators due to their relationship with the reduction in pharmacological response. In this review, updated information about transporters belonging to this superfamily was collected, the possible role of these transporters in cancer, the role of genetic variability in their genes, as well as some therapeutic tools that have been tried to raise against main transporters associated with chemoresistance in cancer.

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作者列表:["Sawada H","Oeda T","Kohsaka M","Tomita S","Umemura A","Park K","Yamamoto K","Kiyohara K"]

METHODS:BACKGROUND:Cholinergic neurotransmission regulates neuroinflammation in Parkinson disease (PD). RESEARCH DESIGN AND METHODS:The authors conducted a delayed-start study of donepezil for cognitive decline in non-demented PD patients. The study consisted of a 96-week randomized placebo-controlled double-blind phase 1, followed by a 24-week donepezil extension phase 2. The primary outcome measure was a change in the Mini-Mental State Examination (MMSE) at week 120. RESULTS:A total of 98 patients were randomly allocated to the early-start (donepezil-to-donepezil) and delayed-start (placebo-to-donepezil) groups. Mean (SD) of the baseline MMSE was 27.6 (2.0) and 28.0 (2.1), respectively. MMSE change at week 120 was better in the early-start group than in the delayed-start group, but the difference was not significant. The MMSE declined in apolipoprotein ε4 carriers, but not in non-carriers, and the factor interaction (intervention × ε4 genotype) was highly significant (P < 0.001). Analyzed with the interaction, the difference was significant (group difference 1.95 [0.33 to 3.57], P = 0.018). The MMSE decline slope in phase 1 was significantly better in the early-start group than in the delayed-start group (P = 0.048). CONCLUSIONS:Cognitive function deteriorated in ε4 carriers, but not in non-carriers, and early-start donepezil may postpone cognitive decline in the former.

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作者列表:["Louvrier A","Terranova L","Meyer C","Meyer F","Euvrard E","Kroemer M","Rolin G"]

METHODS::Since the discovery of dental pulp stem cells, a lot of teams have expressed an interest in dental pulp regeneration. Many approaches, experimental models and biological explorations have been developed, each including the use of stem cells and scaffolds with the final goal being clinical application in humans. In this review, the authors' objective was to compare the experimental models and strategies used for the development of biomaterials for tissue engineering of dental pulp with stem cells. Electronic queries were conducted on PubMed using the following terms: pulp regeneration, scaffold, stem cells, tissue engineering and biomaterial. The extracted data included the following information: the strategy envisaged, the type of stem cells, the experimental models, the exploration or analysis methods, the cytotoxicity or viability or proliferation cellular tests, the tests of scaffold antibacterial properties and take into account the vascularization of the regenerated dental pulp. From the 71 selected articles, 59% focused on the "cell-transplantation" strategy, 82% used in vitro experimentation, 58% in vivo animal models and only one described an in vivo in situ human clinical study. 87% used dental pulp stem cells. A majority of the studies reported histology (75%) and immunohistochemistry explorations (66%). 73% mentioned the use of cytotoxicity, proliferation or viability tests. 48% took vascularization into account but only 6% studied the antibacterial properties of the scaffolds. This article gives an overview of the methods used to regenerate dental pulp from stem cells and should help researchers create the best development strategies for research in this field.

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