Do enamel and dentine caries at 5 years of age predict caries development in newly erupted teeth? A prospective longitudinal study

Abstract

Objective: To explore caries development in children from 5 to 12?years of age, and to study whether enamel caries and dentine caries at 5?years of age could predict caries prevalence at 12?years of age, controlled for child characteristics.

Methods: The study included 3282 children examined at 5 and 12?years of age. Data were collected by clinical examination and questionnaire. Enamel and dentine caries were registered at surface level. Data were tested by t-test and analysed by bi- and multivariate logistic regression. The study was ethically approved.

Results: In 5-year-olds, 15% of the children had dentine caries experience and 21% had enamel caries. In 12-year-olds, 32% had dentine caries experience and 47% had enamel caries. Children with dentine caries experience at 5?years of age had at 12?years of age developed more surfaces with enamel caries (mean 2.8, SD 4.2) and dentine caries experience (mean 1.8, SD 2.5) than other children (p?<?.05). Dentine caries experience at 12?years of age was associated with having only enamel caries (OR 1.6, CI 1.2–2.0) and dentine caries experience (OR 3.2, CI 2.6–3.9) at 5?years of age. Family status and parental education were related to caries development.

Conclusion: Children with caries in primary teeth continued to be caries risk children during the mixed dentition period. In addition to dentine caries experience, enamel caries in primary teeth was a predictor for caries development in young permanent teeth and may be used to improve the caries risk assessment.     

Investigation of the root canal configurations of mandibular permanent teeth in the Turkish population

AIM: To investigate the root and canal morphology of mandibular permanent teeth collected from an indigenous Turkish population. METHODOLOGY: A total of 1400 extracted mandibular permanent teeth were evaluated. The teeth were divided into seven groups as central incisors, lateral incisors, canines, first premolars, second premolars, first molars and second molars in order to evaluate their root canal configurations. Access cavities were prepared and pulp tissue removed using 5.25% sodium hypochlorite solution. The teeth were stored in 5% nitric acid solution for 5 days, then rinsed under running water for 4 h and placed in increasing concentrations of ethyl alcohol. The teeth were rendered transparent by immersion in xylene solution for 3 days until complete transparency was achieved. Following this procedure, India ink was injected in the root canal systems and their configurations were examined and compared with the classification of Vertucci. The following observations were made: (i) root canal classification of mandibular teeth; (ii) morphology of the mandibular permanent teeth. The classification of Vertucci was taken as a reference during the evaluation; however additional canal morphological types were evaluated as separate groups. RESULTS: The presence of a second canal was detected in 68% of mandibular central incisors and 63% of lateral incisors. Lateral canals were found in 6.5% of mandibular central incisors and in 13% of lateral incisors. Overall, 62% of mandibular first premolar teeth had a single canal whereas 71% of second premolars had a single canal. The mandibular first and second molar teeth exhibited similar root canal configurations except for a group of second molar teeth that had a single root and canal. CONCLUSIONS: The morphological characteristics of teeth in this Turkish population were consistent with those of other studies performed on different populations using similar methodology.     

Root fracture in immature anterior teeth followed for 15 years

Abstract –  We report a case of injury to an immature tooth, observed over a period of 15 years. In 1987, a 9-year-old boy fell down in a schoolyard. The right central incisor demonstrated palato-version and radiographic observations revealed that the roots of both central incisors were incomplete. Further, a root fracture in the apical region of the central incisors was observed. During the first treatment visit, the right central incisor was repositioned and both teeth splinted. After confirming that the line of fracture was aligned, the fixation was continued for 2 months. The teeth were examined periodically for the next 15 years. Both teeth had favorable outcomes with continued root development of both the apical and coronal segments with good apposition of the fracture lines.     

犬恒牙牙根正常发育过程中细胞凋亡的研究

目的：探讨细胞凋亡在牙根发育过程中的生理作用。方法：采用原位末端标记技术(TuNEL)，观测犬恒牙牙根发育过程中各组织中凋亡细胞的分布情况：结果：牙根发育时期在成牙本质细胞、牙髓组织、牙乳头组织、上皮根鞘、牙槽骨组织中有特异性细胞凋亡发生。结论：细胞凋亡在牙根发育过程中的发生具有时空特异性，提示其在牙根形态形成过程中发挥重要的生理作用。     

Baseline characteristics as 3-year predictors of tooth fracture and crack progression: Findings from The National Dental Practice-Based Research Network

BackgroundThe authors of this practice-based study estimated the risk of experiencing tooth fractures and crack progression over 3 years and correlated baseline patient-, tooth-, and crack-level characteristics with these outcomes.MethodsTwo-hundred-and-nine National Dental Practice-Based Research Network dentists enrolled a convenience sample of 2,601 participants with a cracked vital posterior tooth that had been examined for at least 1 recall visit over 3 years. Data were collected at the patient, tooth, and crack levels at baseline, annual follow-up visits, and any interim visits. Associations between these characteristics and the subsequent same-tooth fractures and crack progression were quantified.ResultsOf the 2,601 teeth with a crack or cracks at baseline, 78 (3.0%; 95% confidence interval, 2.4% to 3.7%) subsequently developed a fracture. Of the 1,889 patients untreated before year 1, 232 (12.3%; 95% confidence interval, 10.9% to 13.8%) had some type of crack progression. Baseline tooth-level characteristics associated with tooth fracture were the tooth was maxillary and had a wear facet through enamel and a crack was detectable with an explorer, on the facial surface, and in a horizontal direction. Crack progression was associated with males and teeth with multiple cracks at baseline; teeth with a baseline facial crack were less likely to show crack progression. There was no commonality between characteristics associated with tooth fracture and those associated with crack progression.ConclusionsDevelopment of tooth fractures and crack progression over 3 years were rare occurrences. Specific characteristics were associated with the development of tooth fracture and crack progression, although none were common to both.Practical ImplicationsThis information can aid dentists in assessing factors that place posterior cracked teeth at risk of experiencing adverse outcomes.     

Onlay植骨技术在上颌前牙美学区种植修复中的应用

目的:评估Onlay植骨技术在上颌前牙美学区种植修复中的应用。方法:随机选取82例行种植修复术的患者,根据术前评估,给予患者合理的Onlay植骨技术及牙种植修复手术方案。观察患者植骨期间牙槽嵴骨量变化及美学指标变化情况,记录牙种植体存活率。结果:Onlay植骨术后3个月末牙槽嵴水平向骨量(7.84±0.42)mm、牙槽嵴垂直向骨量(11.65±0.85)mm和术后6个月末牙槽嵴水平向骨量(7.15±0.60)mm、牙槽嵴垂直向骨量(10.86±0.63)mm均显著高于植骨前骨量,P=0.035、0.039、0.035、0.040;牙种植修复术后3个月末PES(7.48±1.36)分、WES(7.56±1.09)分和术后6个月末PES(7.78±1.42)分、WES(7.82±1.51)分均显著高于术前评分水平,P=0.040、0.043、0.038、0.032;Onlay植骨术后,骨组织美观丰满,伤口愈合良好,未出现植骨坏死,种植体存活率高。结论:将Onlay植骨技术应用于上颌前牙美学区种植修复中,可显著改善种植区骨量不足的问题,骨愈合情况良好,种植体存活率高,值得推广使用。     

三种品牌人工牙在全口义齿修复中的性能比较

目的 观察三种品牌人工牙制作全口义齿修复7－8年后的磨耗及He关系变化。方法 选择103例全口义齿修复患者，让其自选三种品牌人工牙之一作全口义齿修复，7－8年后复查人工牙He面磨耗程度，颌位和He关系的变化，义齿固位情况及咀嚼效能的自我评价。结果 三种品牌人工牙所作全口义齿7－8年后的He磨耗，义齿固位经秩和统计分析，Ivoclar牌人工牙与ODI和Bayer两种品牌相比差异有显著性（P＜0.05)，ODI与Bayer比较差异无显著性（P＞0.05)。结论 使用 优质的塑脂人工牙作全口义齿修复，能延长全口义齿发挥最佳咀嚼效能时间。     

心理暗示干预在老年人牙拔除术中的应用

目的：探讨心理暗示干预在老年人牙拔除术中的应用价值。方法：将老年人拔牙患者118例随机分为心理暗示组及对照组各59例。心理暗示组在拔牙术前采用心理暗示干预的方法,对照组未给予任何暗示,按照沉稳型、张乱型及混合型三个等级统计数据,进行对比研究。结果：心理暗示组的沉稳型率显著高于对照组（P〈0.01）,张乱型率显著低于对照组（P〉0.05）。结论：心理暗示干预应用于老年人牙拔除术时,可明显降低患者的畏惧程度,缩短手术时间,确保手术的顺利进行,有一定的应用价值。     

The fibrous structure of the cemento-dentinal junction in human molars shown by scanning electron microscopy combined with NaOH-maceration

The cemento dentinal junction was studied in acellular and cellular cementum of human mandibular third molars by scanning electron microscopy combined with NaOH-maceration. Scanning electron microscopy with NaOH-maceration was applied to observe the fibrous structure in detail through long sections of the cemento-dentinal junction. In macerated specimens, the cemento dentinal junction was a fibril-poor groove. Some cemental fibrils or fibril bundles penetrated the groove and appeared to intermingle with dentinal fibrils. Prolonged maceration caused detachment of the cemento-dentinal junction irrespective of fibril intermingling allowing observation of the inner cementum surface facing the root dentin. Observations suggested that the fibril intermingling was point-like and present only in places at the cemento-dentinal junction. It was established that NaOH-maceration removes interfibrillar substances effectively in connective tissues and does no damage to the collagen fibril structure and architecture. This study showed the 3-dimensional fibrous structure of the cemento-dentinal junction in human mandibular third molars, and suggested that interfibrillar adhesive substances are more important than the fibril intermingling for the cemento-dentinal attachment.     

Reasons for replacement of restorations in permanent teeth in general dental practice

OBJECTIVE: The analysis of reasons for the replacement of 9,805 amalgam, composite, glass ionomer, resin modified glass ionomer and 'other' restorations in permanent teeth in general dental practice. DESIGN: The data were subdivided on the bases of age and gender of the patients, the types of restorations and the clinicians' gender, experience and practice setting. RESULTS: The clinical diagnosis of secondary caries was the main reason for replacement of all types of restorations studied, followed by fracture of restorations, especially bulk fracture, irrespective of patient's age. Bulk discoloration was the third most common reason for replacement of resin based materials in adults, but it rarely occurred in adolescents 18 years and younger. The reasons for replacement of restorations were not associated with the gender of the patients. Subgroupings based on the clinicians' gender showed that female clinicians diagnosed secondary caries more often than male clinicians. Otherwise, the reasons for replacements were similar for both genders of clinicians. Subdivision of restorations based on the years since graduation of the clinicians resulted in small groups. The youngest group of clinicians diagnosed relatively more secondary caries both for amalgam and composite restorations than the most experienced group. CONCLUSION: The clinical diagnosis secondary caries was the main reason for replacement of all types of restorations studied.