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.     

Accuracy of High-resolution Small-volume Cone-Beam Computed Tomography in the Diagnosis of Vertical Root Fracture: An In Vivo Analysis

IntroductionThe purpose of this in vivo study was to evaluate the accuracy of small-volume cone-beam computed tomographic (CBCT) imaging compared with conventional periapical radiography (CPR) in the diagnosis of vertical root fractures (VRFs) using exploratory surgery as the reference standard.MethodsEighty-two dental records of 85 teeth with suspected VRFs that underwent CPR, CBCT imaging, and exploratory surgery were included. Two observers assessed CPR and CBCT images independently for the presence or absence of root fractures, and findings from the exploratory surgery were considered the reference standard. Diagnostic sensitivity, specificity, accuracy, and the receiver operating characteristic curve values were obtained. The effect of single- and multirooted teeth on diagnostic accuracy as well as the association between clinical symptoms and the presence of VRFs were also assessed.ResultsVRFs were surgically detected in 64 of the 85 teeth (75.3%), of which 62.5% were multirooted and 76.6% had intracanal posts. CBCT imaging was more sensitive and accurate (65.6% and 64%) than CPR (27.3% and 40.5%). Both CPR and CBCT diagnostic accuracies were higher in single- than multirooted teeth. Pain on percussion, a localized periodontal pocket, and tooth mobility were associated with the presence of VRFs (P < .05; odds ratio = 4.15, 13.5 and 4.1, respectively).ConclusionsThe accuracy of CBCT imaging for the diagnosis of VRFs was poor, although it was higher than with CPR. Multirooted teeth in the presence of intracanal posts may limit its diagnostic value.     

Biodentine Pulpotomies on Permanent Traumatized Teeth with Complicated Crown Fractures

IntroductionThe aim of this multicentric prospective study was to evaluate the clinical and radiographic outcomes of Biodentine (BD) pulpotomies on permanent teeth with complicated crown fractures.MethodsThis study was carried out in 2 hospital-based dental departments in Quebec, Canada. Children seeking emergency care after trauma to anterior permanent teeth were invited to participate in this study. The treatment outcome was assessed clinically and radiographically at 1 week and 1, 3, 6, 12, 18, and 24 months after treatment.ResultsForty-five patients between the ages of 8 and 16 years (mean, 10.8 ± 2.4) were included in this study. Fifty-one teeth were treated with a BD pulpotomy. The study showed a survival rate of 100% and a success rate of 91%. Four failures were noted at 1-, 6-, and 15-month follow-up, and the teeth were subsequently treated with either conventional root canal therapy or regenerative endodontic procedure. Dental sensitivity to cold reported by patients reduced over time, and more teeth responded normally to pulp vitality tests during the course of this study. Slight discoloration was noted on 8 teeth (17%). Radiographic outcomes showed dentinal bridge formation in 91% of cases, and all immature teeth showed continued root formation.ConclusionsBD is a suitable material for pulpotomies on anterior permanent teeth with complicated crown fractures. It may be a good alternative to mineral trioxide aggregate pulpotomies because it does not cause significant discoloration, and it allows root maturation.     

Retrospective radiological evaluation to study the prevalence and pattern of maxillofacial fracture among Military personal at Prince Sultan Military Medical City [PSMMC], Riyadh: An institutional study

PurposeThe aim of the present study was to analyze the prevalence, causes, and patterns of maxillofacial fractures retrospectively in patients who were treated at Prince Sultan Military Medical City, Riyadh, Saudi Arabia.MethodsPatients′ medical records were reviewed from 2005 to 2014. Patient′s age, gender, cause, and the pattern of maxillofacial fractures were studied. Associated body injuries were also recorded.ResultsOut of 263 patients, 207 (78.7%) were male and 56 (21.3%) were female. The age range was from 3 to 67 yr with a mean age of 26.21 yr. Road traffic accidents 236 (89.8%) were the most commonly reported cause of maxillofacial fractures, followed by falls 14 (5.3%), assaults 4 (1.5%), gunshot 3 (1.1%), and sport accidents 2 (0.8%). Most of the cases of maxillary fracture were Le Fort II 27 (36.5%), followed by LeFort I 23 (31.1%), LeFort III 20 (27.0%) and palatal fractures 4 (5.4%). Of the mandibular fractures, parasymphysis fractures constituted 61 (27.4%), body 50 (22.4%), condyle 45 (20.2%), angle 40 (17.9%), symphysis 16 (7.2%), ramus 7 (3.1%) and coronoid 4 (1.8%). Zygomatic complex fractures 110 (94.8%) were the most commonly reported fractures in the mid and upper facial region. Other facial fractures included orbital floor 61 (97.0%), naso-orbito-ethmoidal 18 (19.8%), and frontal 12 (13.2%).ConclusionRoad traffic accidents were the most common cause of maxillofacial fractures. Spreading awareness among young drivers regarding road safety regulations is highly recommended.     

International Association of Dental Traumatology guidelines for the management of traumatic dental injuries: 2. Avulsion of permanent teeth

Avulsion of permanent teeth is one of the most serious dental injuries. Prompt and correct emergency management is essential for attaining the best outcome after this injury. The International Association of Dental Traumatology (IADT) has developed these Guidelines as a consensus statement after a comprehensive review of the dental literature and working group discussions. It represents the current best evidence and practice based on that literature search and expert opinions. Experienced researchers and clinicians from various specialties and the general dentistry community were included in the working group. In cases where the published data did not appear conclusive, recommendations were based on consensus opinions or majority decisions of the working group. They were then reviewed and approved by the members of the IADT Board of Directors. The purpose of these Guidelines is to provide clinicians with the most widely accepted and scientifically plausible approaches for the immediate or urgent care of avulsed permanent teeth. The IADT does not, and cannot, guarantee favorable outcomes from adherence to the Guidelines. However, the IADT believes that their application can maximize the probability of favorable outcomes.     

International Association of Dental Traumatology guidelines for the management of traumatic dental injuries: General introduction

Traumatic dental injuries (TDIs) occur most frequently in children and young adults. Older adults also suffer TDIs but at significantly lower rates than individuals in the younger cohorts. Luxation injuries are the most common TDIs in the primary dentition, whereas crown fractures are more commonly reported for the permanent teeth. Proper diagnosis, treatment planning and follow up are very important to assure a favorable outcome. These updates of the International Association of Dental Traumatology's (IADT) Guidelines include a comprehensive review of the current dental literature using EMBASE, MEDLINE, PUBMED, Scopus, and Cochrane Databases for Systematic Reviews searches from 1996 to 2019 and a search of the journal Dental Traumatology from 2000 to 2019. The goal of these guidelines is to provide information for the immediate or urgent care of TDIs. It is understood that some follow‐up treatment may require secondary and tertiary interventions involving dental and medical specialists with experience in dental trauma. As with previous guidelines, the current working group included experienced investigators and clinicians from various dental specialties and general practice. The current revision represents the best evidence based on the available literature and expert opinions. In cases where the published data were not conclusive, recommendations were based on the consensus opinions of the working group. They were then reviewed and approved by the members of the IADT Board of Directors. It is understood that guidelines are to be applied using careful evaluation of the specific clinical circumstances, the clinician's judgment, and the patient's characteristics, including the probability of compliance, finances and a clear understanding of the immediate and long‐term outcomes of the various treatment options vs non‐treatment. The IADT does not, and cannot, guarantee favorable outcomes from adherence to the Guidelines. However, the IADT believes that their application can maximize the probability of favorable outcomes.     

离体下颌前磨牙预备状况与贴面抗折性的关系

目的:旨在比较下颌前磨牙牙体预备和不预备后制备全瓷贴面和复合树脂贴面的抗折力。方法:40个新鲜离体下颌前磨牙随机分为4组(n=10):NPR组(牙体不预备直接0.2 mm厚树脂贴面修复);NPC组(牙体不预备直接0.2 mm厚铸瓷贴面修复);P2C组(牙体预备0.2 mm,修复0.2 mm厚铸瓷贴面);P5C组(牙体预备0.5 mm,修复0.5 mm厚铸瓷贴面),预备面均包绕颊侧延伸颌面1 mm。所有试件常规粘接后进行冷热循环实验(10000次/5~55℃),在万能材料试验机下进行抗折测试(2 KN,0.5 mm/min),断裂面放大10倍分析,数据方差检验。结果:各组抗折力均值分别为:NPR=(690.33±233),NPC=(790.52±408),P2C=(1131.34±341),P5C=(983.56±202)。所有组均有统计学差异(P<0.05),NPR、NPC组抗折力均小于P2C,然后P5C组抗折力与其余各组差距不明显。断裂分析显示断裂面呈现混合断裂(60%),内聚断裂(20%),根裂(15%),粘接断裂(5%)。结论:微量(0.2 mm)的前磨牙牙体预备后修复全瓷贴面可获得最大抗折力,当预备超过0.5 mm时可能会发生牙体折裂。     

34例髁突骨折伴发外耳道骨折临床分析

目的: 探讨髁突骨折与外耳道骨折的关系及同期手术的必要性。方法: 230例320侧髁突骨折根据骨折线位置不同分为矢状（Ⅰ型）、头部 （Ⅱ型）、颈部 （Ⅲ型）、髁突下（Ⅳ型）4种类型, 随访髁突与外耳道骨折同期手术与否的预后差异。采用SPSS 20.0软件包中的χ²检验,比较不同类别髁突骨折伴同侧外耳道骨折之间的差异。结果: 230例320侧髁突骨折伴外耳道骨折34例46侧,Ⅰ~Ⅳ型分别为12侧、16侧、7侧、5侧,另有6侧外耳道骨折无髁突骨折。Ⅲ型髁突骨折伴同侧外耳道骨折发生率显著低于另外3型（P<0.05）;Ⅰ型髁突骨折伴外耳道骨折的发生率显著高于Ⅳ型（P<0.05）,其他各型之间两两比较无显著差异。22例30侧随访至受伤后6个月,5例8侧在排除外耳道脑脊液漏的情况下,同期行髁突及外耳道骨折治疗,术后6个月外耳道无狭窄,听力无下降;另17例22侧均出现不同程度的外耳道狭窄,其中4例5侧出现严重听力障碍（均为外耳道粉碎性骨折）。结论: 髁突颈部骨折伴外耳道骨折的概率较低,而髁突矢状骨折较基底部骨折更易导致外耳道骨折。治疗颌面部骨折,应早期发现、治疗外耳道骨折,积极预防外耳道狭窄、听力下降等并发症。