The Maillard reaction in demineralized dentin in vitro

The Maillard reaction between carbohydrate and protein has been proposed as a cause of the browning of carious lesions. The aim of the present investigation was to determine the occurrence of this reaction in bovine dentin collagen in vitro and to establish the effect of the reaction on the proteolytic degradation of bovine dentin collagen in vitro. Slices of demineralized bovine dentin were incubated with 0.2 M glucose or buffer for 10 weeks at 37°C. The formation of initial (furosine) and advanced (pentosidine) products of the Maillard reaction in dentin exposed to glucose was confirmed by HPLC. After reduction with NaBH₄ to prevent intermediate Maillard products from further reaction, slices were either degraded with collagenase for fluorescence measurement or incubated with trypsin or pepsin to assess enzymatic degradation. Fluorescence characteristic for the Maillard reaction increased in glucose-exposed slices. Degradation of collagen by pepsin, but not by trypsin, was greatly depressed following glucose pretreatment. This may indicate an altered sensitivity to proteolytic degradation; the Maillard reaction thus has a potential role in caries arrestment.     

Concomitant intrusive luxation and root fracture of a central incisor - report of a case

Abstract A case of a 9-year-old boy who presented with intruded maxillary central incisors, one of which had also sustained a middle third root fracture, is reported. The root fracture was diagnosed after orthodontic extrusion was started, which resulted in separation of the apical and coronal fragments. The hypermobile coronal fragment was stabilised by passing a K file through a palatal access cavity into the root canal of the apical fragment. Orthodontic alignment was completed and the fractured incisors were restored with the file left in situ. At a 10-year follow-up, the incisors were clinically healthy and continued to satisfy aesthetic and functional demands.     

Two types of intraoral distribution of fluorotic enamel

Abstract Different distributions of fluorotic dental enamel within the dentition have been described in the literature. This report describes two patterns of intraoral distribution. In nine Tanzanian low fluorosis communities with a prevalence of pitting fluorosis of less than 2% and in live moderate fluorosis communities with a prevalence of pitting fluorosis of 16–59%, incisors and first molars were the least affected teeth. In four high fluorosis communities with a prevalence of pitting fluorosis of 86–97%, maxillary incisors exhibited lower Thylstrup-Fejerskov Index values than the maxillary canines, premolars and molars. The mandibular teeth exhibited increasing Thylstrup-Fejerskov Index values from the anterior to the posterior region. The curves presenting the intraoral distribution of the severity of dental fluorosis corresponded with the curve presenting the completion time of primary enamel formation of the various tooth types, with the exception of the first molars in high fluorosis communities. The similarity of the curves suggests that the later in life enamel is completed, the higher is the severity of dental fluorosis. This relation seems to be explained by the prevailing feeding and dietary habits, which result in minimal intake of fluoride in the first 18 months of life during breastfeeding, followed by increasing fluoride ingestion in the following years through consumption of tea, seafish and F-containing magadi salt.     

A clinical comparison of 2 electric toothbrush designs

Abstract A single blind 30 day study compared the reduction of plaque and gingivitis for the Hapika® Powerbrush to the Interplak® ultra 10 tuft. A longitudinal parallel group design was utilized and screening evaluation was performed to determine patient eligibility prior to study enrollment. 66 subjects were entered into the study and assigned to 1 of 2 groups, each using one of the toothbrushes. At baseline, subjects received an oral soft tissue exam, a dental hard tissue exam, and were scored by the Lobene modification of the Löe and Silness gingival index (GI). Plaque was then disclosed and scored both pre and post brushing using the modified Turesky plaque/debris examination and an interproximal bleeding examination was performed post-brushing. On days 15 and 30, after an oral soft tissue and GI examination, plaque was graded by the Modified Turesky plaque/debris exam. Subjects then brushed and were graded by the Modified Turesky plaque/debris examination and an interproximal bleeding index examination. The results showed that both brushes provided a similar change in clinical indices. All produced a statistically significant reduction from baseline to day 30 for the gingival index (26.5-29.1%), the bleeding index (13.8-24.1%), and the plaque index (16.9-19.4%), A comparison of pre and post brushing scores for the plaque index at 30 showed that both brushes reduced plaque similarly with a statistically significant reduction (P<0.05) from their pre-brushing plaque index scores at all time periods.     

乳牙釉质表面氟浓度与患龋状况的关系

目的 探讨牙齿不同部位之间、易患龋牙与非易患龋牙之间牙釉质表面氟浓度有无差异。方法 收集上海、北京和深圳3个地区儿童的下颌乳中切牙45颗,并利用微样酸蚀法分析乳牙釉质表面氟元素的分布。结果 氟浓度从釉质表面到内部有由高到低的变化趋势,牙磨耗是牙齿丧失氟的重要元素,未发现釉质表层氟浓度与龋蚀指数(CSI)、龋补牙数(dft)有相关性(P>0.05)。结论 乳牙釉质表面氟浓度与患龋状况无明显相关性。     

Treatment of traumatized primary teeth: a conservative approach

This retrospective study examined some different types of treatment to primary teeth. The aim of this study was to assess the treatment of traumatized primary teeth and the importance of a long-term follow up. Brazilian children in the age group of 1-4 years from a baby clinic took part in the study. Three hundred and fifteen patients suffered some type of traumatic injury, a total of 338 affected teeth. Data were registered in specific records and submitted to statistic analysis. The most prevalent type of treatment was monitor only (85%) followed by tooth extraction and endodontic procedure. Invasive treatments were performed in case of severe traumas, usually 6 months after the injury. We verified that a careful follow up might be the preferential choice to the treatment of traumatic primary teeth even in some severe cases.     

功能性矫治器在正畸矫治中运用的伦理思考

功能性矫治器是正畸临床中常用的一种矫治器，作者从口腔正畸学理论基础出发，探讨了功能性矫治器在正畸矫治作用中存在的伦理道德问题，主要有（1）不能正确的诊断、制定周密的矫治计划。（2）操作不规范、不细致、缺乏敬业精神。（3）态度简单，粗曝，缺乏与患者良好的交流。并提出解决方法（1）刻苦学习专业知识，不断提高诊疗水平及个人修养。（2）建立高度的道德责任感，以严谨的作风，规范的操作为病人服务。（3）尊重、善待青少年，建立良好的医患关系。     

Skilled birth attendant competence: an initial assessment in four countries, and implications for the Safe Motherhood movement.

OBJECTIVES: Percentage of deliveries assisted by a skilled birth attendant (SBA) has become a proxy indicator for reducing maternal mortality in developing countries, but there is little data on SBA competence. Our objective was to evaluate the competence of health professionals who typically attend hospital and clinic-based births in Benin, Ecuador, Jamaica, and Rwanda. Methods: We measured competence against World Health Organization's (WHO) Integrated Management of Pregnancy and Childbirth guidelines. To evaluate knowledge, we used a 49-question multiple-choice test covering seven clinical areas. To evaluate skill, we had participants perform five different procedures on anatomical models. The 166 participants came from facilities at all levels of care in their respective countries. Results: On average, providers answered 55.8% of the knowledge questions correctly and performed 48.2% of the skills steps correctly. Scores differed somewhat by country, provider type, and subtopic. Conclusion: A wide gap exists between current evidence-based standards and current levels of provider competence.     

Guided bone regeneration for immediate non‐submerged implant placement using bioabsorbable materials in Beagle dogs

The aim of the present study was to evaluate the combined application of different bioabsorbable materials for healing of residual peri‐implant defects after placement of non‐submerged implants into fresh extraction sockets. Second and third mandibular premolars were extracted from 10 Beagle dogs, the coronal part of the distal sockets were surgically enlarged and this was followed by immediate placement of specially designed hollow‐screw non‐submerged dental implants. For each animal, the coronal peri‐implant defects were further treated with one of the 4 following procedures: 1) no treatment, control site: 2) grafting with porous hydroxyapatite (HA); 3) collagen membrane tightly secured around the implant and over the defect and 4) grafting with HA covered with a collagen membrane. After 16 weeks of healing, specimens were removed from the mandibule and prepared for a histomorphometric evaluation. The bone-to-implant contact length (BIC) was measured and compared amongst the different treatment modalities. In the defect area, the irregular bone regeneration was similar between all the treatment procedures ( P >0.10). In the sites covered with a collagen membrane alone, the total BIC (47%) was greater than in control sites (28.7%. P <0.05) or sites grafted with HA (22.2%, P <0.02). Total BIC in sites treated with the HA‐membrane combination (43%) was only significantly different from sites treated with HA ( P <0.10). It is concluded that the use of bioabsorbable materials results in a limited increase of osseointegration when used in conjunction with immediate placement of non-submerged implants, although the principle of the one stage surgical approach can be maintained.