牙冠延长术在残根残冠修复中的临床疗效

目的评价牙冠延长术在牙体缺损达龈下的残根残冠修复中的临床疗效。方法自2004年5月至2005年6月,对32例患者的36颗牙体缺损达龈下的患牙,术前按断端位于龈下最深距离分为A组(20颗患牙,距离<3.0mm)和B组(16颗患牙,3.0mm≤距离≤4.0mm),均采用牙冠延长术暴露龈下牙体断面,术后6周行桩冠修复。分别记录和比较手术前、后牙周探诊深度(PD)、菌斑指数(PLI)、龈沟出血指数(SBI)和牙齿松动度,以观察临床疗效。结果术后随访患者6个月,两组病例术后6周牙体断端均暴露较好、龈缘颜色正常,术后修复效果有效率为100%,满意率为77.78%。A组术后无松动,修复效果满意;B组术后50.00%出现Ⅰ度松动,修复效果欠佳,两组修复效果比较差异有显著意义(P<0.05)。术后各阶段两组的PD、PLI、SBI均明显优于术前(P<0.05),但两组术后牙周指数比较差异无显著意义(P>0.05)。结论牙冠延长术有利于残根残冠的保存和修复,但要注意适应证的选择。     

Shorter sentences for drug mules: The early impact of the sentencing guidelines in England and Wales

Abstract

Aims: In February 2012, new sentencing guidelines for drug offences became effective in all courts in England and Wales. An explicit aim was to reduce the length of sentences for drug “mules” and so make them more proportionate. Methods: This article examines their early impact drawing on data from the Court Proceedings Database and the Crown Court Sentencing Survey for importing/exporting a Class A drug. Findings: Overall, the guidelines have achieved their intended aim. The length of the average custodial sentence for drug trafficking fell following the introduction of the guidelines, largely due to taking defendants' roles into account. Notably, three-quarters of those in “lesser” roles received sentences less than four years, representing an important change. Nonetheless, around 10% of mules received very long sentences due to the continued use of drug weight in sentencing. Conclusion: The new guidelines represent an internationally important innovation in drug policy reform.     

58例年轻恒牙外伤冠折的处理分析

目的：探究年轻恒牙外伤冠折的临床处理方法及效果。方法选择该院2009年3月—2014年9月口腔科门诊就诊年轻恒牙不同程度的外伤冠折的患者58例,依据不同临床表现分别给予直接盖髓术,活髓切断术,根尖诱导术治疗后对患牙进行随诊观察。结果治疗成功患牙52颗,占89%。结论对于年轻恒牙的外伤冠折,选择好正确的治疗方法,大多数患牙能保存牙髓活力,牙根能继续发育,永久性修复后患牙功能良好。     

Treatment Outcomes of Permanent Immature Teeth with Crown Fracture: A Retrospective Cohort Study

IntroductionCrown fractures are a common type of traumatic dental injury. Various factors may affect the outcome of crown fractures. This study aimed to evaluate the treatment outcomes of immature teeth with a crown fracture.MethodsThis retrospective cohort study included patients who presented to a dental trauma center from 2008–2018 with a history of a crown fracture of immature teeth and at least 6 months of follow-up. Outcomes of primary endodontic or restorative interventions as well as reinterventions were evaluated. Kaplan-Meier curves were used to compare the unadjusted differences in survival time. Logistic and Cox regression analyses were performed to identify potential predictors for complication and survival time, respectively.ResultsThe success rates of the primary interventions for 99 teeth (72 patients) after a median follow-up of 22 months were as follows: cervical pulpotomy (90.4%), partial pulpotomy (85.2%), mineral trioxide aggregate apical barrier (80.0%), root canal treatment (66.6%), and only restoration (47.2%). Teeth that received vital pulp therapy were less prone to complications (adjusted hazard ratio = 0.21; 95% confidence interval, 0.09–0.53; P < .05), whereas those with concomitant luxation injuries were more susceptible to complications (adjusted odds ratio = 2.90; 95% confidence interval, 1.01–8.29; P < .05).ConclusionsCrown fractures had a relatively high favorable prognosis. Vital pulp therapy (partial or cervical pulpotomy) had the highest success rate, whereas cases that received only restoration had the lowest success rate. Teeth with concomitant luxation injuries had more odds and hazards of complications.     

Mechanical behavior of nano-hybrid composite in comparison to lithium disilicate as posterior cement-retained implant-supported crowns restoring different abutments

ObjectiveResin-based materials are gaining popularity in implant dentistry due to their shock absorption capacity. Therefore, the aim of this study was to evaluate the fracture strength and failure mode of resilient materials for both crowns and abutments and compare them to the most widely used materials in different combinations after subjection to long-term fatigue loading.MethodsForty-eight cement-retained implant-restorations were assembled on titanium implants. Identical custom-made CAD/CAM abutments were milled out of 3 different materials (n = 16); T: titanium, Z: zirconia and P: ceramic-reinforced PEEK. Each group was subdivided, according to the restorative crown material, into two subgroups (n = 8); C: nano-hybrid composite and L: Lithium disilicate. Specimens were subjected to dynamic load of 98 N for 1,200,000 cycles with integrated thermal cycling. The surviving specimens were subjected to quasi-static loading until failure. Shapiro–Wilk test was used to test for normality. One-way ANOVA followed by Tukey’s post-hoc test was used to detect statistically significant differences between groups.ResultsAll specimens withstood 1,200,000 load cycles. The fracture strength values varied from a minimum of 1639 ± 205 N for group PL to a maximum of 2949 ± 478 N for group ZL.SignificanceThe abutment material influenced the fracture strength and failure mode of the restoration. A combination of zirconia abutments and nano-hybrid composite showed the most favorable mode of failure within the test groups. Therefore, this combination might be recommended as an alternative for restoring single implants in the posterior area.     

牙冠延长术后桩核修复在牙体缺损至龈下残根残冠患者中的应用观察

目的观察牙冠延长术后桩核修复在牙体缺损至龈下残根残冠患者中的应用效果。方法选取我院2016年10月~2019年11月期间接收的牙体缺损至龈下残根残冠患者140例,根据随机数字表法分成研究组(70例)与对照组(70例),其中对照组接受直接桩核冠修复治疗,研究组接受牙冠延长术后桩核修复治疗。比较两组临床疗效、美观满意度、治疗前与治疗后龈沟液中炎性因子[一氧化氮(NO)、白细胞介素-1β(IL-1β)、前列腺素E2(PGE2)]水平以及治疗前、治疗6周、3个月牙周状况[探诊深度(PD)、龈沟出血指数(SBI)]。结果研究组总有效率97.14%(68/70),较对照组80.00%(56/70)高(P<0.05);治疗6周、3个月研究组PD浅于对照组,SBI少于对照组(P<0.05);治疗3 d,研究组NO、PGE2、IL-1β水平低于对照组(P<0.05);与对照组88.57%(62/70)对比,研究组美观满意度98.57%(69/70)明显较高(P<0.05)。结论牙冠延长术后桩核修复应用于牙体缺损至龈下残根残冠患者中,可增强治疗效果,改善牙周恢复状况,减轻龈沟液中炎性因子,并提高美观度。     

氢氧化钙糊剂在年轻恒牙牙髓切断术中的应用

目的探讨氢氧化钙糊剂用于年轻恒牙牙髓切断术的临床效果。方法对2016年1月～2017年11月来我科就诊的46例患儿的外伤冠折露髓后行牙髓切断术的51颗年轻恒前牙的治疗效果进行比较分析及随访观察。结果经过1～2年的随访观察,51颗年轻外伤恒牙行牙髓切断术后,成功45颗,失败6颗,成功率为88.2%。不同治疗时间段患者治疗效果对比显示,外伤后就诊越早,露髓孔感染的机率越小,牙髓切断术的成功率就越高,其差异有统计学意义(P0.05)。伤后1～24 h治疗的43颗牙(40例)总有效率为93.0%。结论氢氧化钙糊剂具有很好的杀菌消毒作用,对组织无刺激,可诱导牙本质桥的形成,能有效地保护年轻恒牙的根髓活力,使年轻恒牙的牙根继续发育,并形成良好的根尖形态,建立正常的根尖周组织结构,是年轻恒牙牙髓切断术的首选盖髓剂。     

自酸蚀粘结剂应用于年轻恒中切牙冠折修复的效果

目的评价自酸蚀粘结剂用于年轻恒中切牙冠折充填修复治疗的效果。方法选择年轻恒上颌中切牙牙冠牙釉质-牙本质折断而未露髓的患者106例137颗患牙,按抛硬币方法分为试验组和对照组。试验组的56例74颗患牙使用自酸蚀粘结剂处理牙面;对照组的50例63颗患牙常规间接盖髓、酸蚀剂和粘结剂处理牙面。2组用相同光固化复合体修复牙冠外形,调牙合抛光,观察2组修复后1个月、3个月、6个月、1年、2年的疗效。结果治疗后1个月、3个月、6个月、1年、2年,试验组成功率分别为97.30%、97.30%、94.59%、94.59%、94.59%,对照组成功率分别为95.24%、95.24%、90.48%、88.89%、88.89%,试验组成功率高于对照组,但差异均无统计学意义(P>0.05)。结论应用自酸蚀粘结剂粘结充填修复牙釉质-牙本质折断而未露髓的年轻恒中切牙效果良好。     

Fatigue resistance and microleakage of CAD/CAM ceramic and composite molar crowns

Purpose: The aim of this study was to determine effect of compressive cyclic loading on fatigue resistance and microleakage of monolithic CAD/CAM molar ceramic and composite crowns. Materials and Methods: Thirty‐two extracted molars were prepared to receive CEREC crowns according to manufacturer's guidelines using a special paralleling device (Parallel‐A‐Prep). Sixteen feldspathic ceramic crowns (VITABLOCS Mark II) (VMII) and 16 resin‐composite crowns (Paradigm‐MZ100 blocks) (PMZ) were milled using a CEREC‐3D machine. Eight crowns of each group were cemented to their respective teeth using self‐etching resin cement (Panavia‐F‐2.0) (PAN), and eight were cemented using self‐adhesive resin cement (RelyX‐Unicem‐Clicker) (RXU). Following storage for 1 week in water, specimens were subjected to uniaxial compressive cyclic loading in an Instron testing machine at 12 Hz for 1,000,000 cycles. Load was applied at the central fossa, and the cycle range was 60–600 N. Specimens were then subjected to microleakage testing. Data were statistically analyzed using factorial ANOVA and Post Hoc (Tukey HSD) tests. Results: All composite crowns survived compressive cyclic loading without fracture, while three ceramic crowns from the subgroup cemented with RXU developed surface cracks at the center of occlusal surfaces, extending laterally. Microleakage scores of ceramic crowns cemented with PAN were significantly lower than those of the other three subgroups (p < 0.05). Conclusions: After 1,000,000 cycles of compressive cyclic loading, PMZ composite molar crowns were more fatigue‐resistant than VMII ceramic crowns. Cement type had a significant effect on fatigue resistance of the ceramic crowns but not the composite ones. Microleakage scores of ceramic crowns cemented with PAN were significantly lower than those of the other subgroups (p < 0.05).     

全冠修复治疗隐裂牙

目的观察全冠修复治疗隐裂牙的临床效果。方法选择130颗确诊为隐裂牙的牙齿,按隐裂牙病变的不同程度分为两组。A组：早期组,为牙隐裂而无牙髓症状者;治疗时,先行牙体预备,然后烤瓷全冠修复;B组：晚期组,为牙隐裂有牙髓症状者;治疗时先行完善的根管治疗,之后进行烤瓷全冠修复治疗。分别在6个月、1年及2年随访一次。结果经全冠修复治疗的各期隐裂牙,随访效果满意。结论全冠修复治疗各期牙裂对延长患牙的使用寿命及患者咀嚼功能的提高作用良好。