Evidence of the validity of a model of determinants of quality of restorative dental care

A model describing the relationship between self-reported quality of restorative dentistry and dentist characteristics for 119 Montana general dentists is presented. The best predictors formed a significant model explaining 22% of the variance of the quality measure. Results are contrasted with a previous estimation of the model for 102 Washington general practitioners. Evidence for the external validity of the model is presented.     

Results of treatment of cancer of the lip

A study was carried out in Sancti Spiritus Province in the 1984-1986 period about the results of the treatment of lip cancer. Male patients were the most affected by lip cancer (CIE 8-140) in our series. The place of the tumor was predominantly the lower lip (p less than or equal to 0.001). Surgical treatment was used in 96.8% of the cases and the cuneiform (wedge-shaped) exeresis was the most commonly used method in the early stages of the disease (T1 y T2). Casta?ón keloplasty was the reconstructive procedure used in 18.7% of the patients. Local sepsis was present in 31.2% of the patients undergoing surgery, occurring most frequently in upper lip tumors.     

口底癌34例临床分析

目的探讨口底癌的临床特性、治疗方法及预后。方法对我院自1992—2002年住院治疗的34例口底癌患者进行回顾性分析。结果34例口底癌患者中,男28例(82.4%),女6例(17.6%),男女比为4.7∶1,平均发病年龄58岁。发病部位:前口底22例(64.7%),后口底12例(35.3%)。淋巴结转移率41.2%。单纯手术组、化疗加手术组、放疗加手术组、化疗加手术加放疗组的5年生存率分别为45.5%、60.0%、50.0%、62.5%。结论口底癌以中老年患者好发,男性居多。易发生淋巴结转移,综合疗法疗效较好。     

平阳霉素对血管内皮细胞急性损伤后酶活性变化的实验研究

目的：探讨平阳霉素损伤血管内皮细胞的机制,为临床应用提供组织学依据。方法：选用成年Wistar大白鼠42只（其中6只为正常对照）,经肠系膜静脉分别注入平骒霉素（24只）或鱼肝油酸钠（12只）后,分别于注药后0．5,1,2,4,8,24h,切取肝脏组织,通过酶组化染色法测定肝窦内皮细胞的5’－核苷酸酶,肝细胞的琥珀酸脱氢酶（SDH）及乳酸脱氢酶（LDH）活性,结果：注入药液后,肝窦内皮细胞的5’－核苷酸酶,肝细胞的SDH和LDH活性随时间逐渐下降,其中平阳霉素组下降较轻微,结论：平阳霉素和鱼肝油酸钠都可对血管内皮细胞产生损伤,损伤的性质一样,均为非特异性,但平阳霉素损伤程度轻微,而鱼肝油酸钠严重。     

Experimental evidence of formation of imines in the course of reduction of hydrazones

The reduction of hydrazones is generally suggested to proceed through a reductive cleavage of the nitrogen–nitrogen bond followed by a reduction of the carbon–nitrogen bond. This sequence of reduction processes is here supported for fluorenone (V) and benzophenone (VI) hydrazones as well as by a comparison of the reduction of fluorenone and benzophenone hydrazonium ions (I,III) with corresponding imines (II,IV). Another proof of the presence of imines as intermediates is the splitting of four-electron waves of hydrazones V and VI and hydrazonium ions I and VIII into two waves at pH < 2. This has been interpreted as due to differences in slopes dE_1/2/dpH and pK_a-values of protonated hydrazine derivatives on one side and corresponding imines on the other. In this pH-range imines formed in reductions of VI and VIII are reduced in a single two-electron wave, those of I and V in two one-electron steps. Fluorenone imine (II) is sufficiently stable to allow recording of time-independent current–voltage curves between pH 6 and 11. In this pH-range the imine (II) is reduced in two one-electron steps. Benzophenone imine (IV) has been found stable between pH 4.6 and 12. At pH 4.6–8 the reduction of the imine IV takes place in a single two-electron step, at pH 8–12 in two one-electron steps. Final proof of the initial cleavage of the N–N bond is presented by comparison with the reduction of nitrones.     

Design of clinical trials of traditional therapies of periodontitis

The present paper on the design of clinical trials of periodontal therapy first addresses the issue of the etiology of periodontal disease. It is suggested that most if not all forms of destructive periodontal disease are caused by microorganisms and that there are different forms of disease with different microbial etiologies. The progressive nature of destructive periodontal disease is subsequently discussed and it is emphasized that, in a given patient, periodontal sites which show signs of inflammation and attachment loss may not over a period of several months and years show further sign of attachment loss. The present methods of assessing periodontal disease do not allow us to discriminate between potentially active and inactive sites in untreated patients. The significance and variability of indicators of periodontal disease such as bleeding on probing, probing pocket depth and probing attachment level measurements are discussed. The errors inherent in the various measurements are analyzed and suggestions are presented describing how alterations in any of the above parameters could be identified and presented in a clinical trial. Of concern for the statistical analysis of clinical data of periodontal disease is the definition of the "experimental unit". For a number of years, the "experimental unit" in periodontal trials was the patient. It is clear, however, that different sites within the same individual show different patterns of disease progression and lesion morphology and often respond differently to periodontal therapy. Statistical analyses must consequently be designed which recognize differences in site-to-site infection and lesion morphology within a common host. Until such analyses are available, the investigator should be wary of pooling data within the same individual, since such pooling may obscure meaningful alternatives which may take place in individual periodontal sites. Some goals of periodontal therapy are subsequently identified. 4 goals are discussed more in detail, namely: to establish conditions which will allow the patient to maintain a dentition without further breakdown of the periodontium; to reduce pocket depth to establish an anatomy in the dentogingival region which with proper maintainance care will prevent the re-establishment of the subgingival infection; to gain attachment as a result of treatment; to assess the effect of a certain chemotherapeutic agent on periodontal disease.     

Comparative analysis of results of mathematical simulation of stressed deformed status of pin dentures of different design

A computer study of 99 types of mathematical models of teeth armed with stump pin insertions widely used in dentistry (group 1--anchor pins and group 2--cast pin insertions suggested by the authors). Tooth models differed by shape, size, and properties of the design material. The shape and parameters of stump pin insertion were proven to be more significant than the properties of design material. The choice of pin design is determined by the clinical situation, topography and anatomy of tooth crown destruction, and maxillodental disease.     

Evaluation of Effects of Application of a Citroxain-Containing Dentifrice

The benefits to the patient of the removal of tooth deposits is well documented. Should such removal provide the additional effect of "whitening" the tooth surface, an additional cosmetic benefit would be provided. This study documents that a Citroxain-containing dentifrice provides all of these benefits.     

正畸患者切牙影像失真发生情况分析

目的研究正畸患者曲面体层片上的切牙影像失真发生情况，并分析其原因。 方法从中山大学附属口腔医院放射科影像数据库中选取500例正畸患者的曲面体层片和头影测量侧位片，所有曲面体层片均采用咬合杆投照，分别从切牙牙体影像放大、缩小、牙根变短、根尖模糊等评价指标分析上下颌切牙影像失真的发生情况，在头影测量侧位片上测量中切牙根尖-对颌切牙切缘的距离，探讨切牙影像失真发生的原因。采用SPSS 19.0统计软件对所得数据进行统计学检验。 结果500例患者中，切牙牙体影像正常者共417例，切牙牙体影像失真者共83例，影像失真发生率16.6%，其中切牙牙体影像放大17例、牙体影像缩小0例、牙根变短30例，牙根影像变短伴模糊36例。影像失真患者的根尖-切缘距离大于影像正常的患者，差异有统计学意义（F = 5 187.18，P = 0）；影像失真患者的覆盖值大于影像正常的患者，差异有统计学意义（F>477，P = 0）。 结论严重牙颌面畸形如反 、深覆盖是导致曲面体层片的切牙影像失真的主要原因之一。     

Evaluation of efficacy of chemiluminescence for diagnosis of leukoplakia

ObjectiveLeukoplakia is the most common potentially malignant disorder preceding oral cancer. Chemiluminescence has been developed as an adjunct to conventional examination for the diagnosis of these potentially malignant disorders. This study was conducted to assess the efficacy of chemiluminescence in the diagnosis of leukoplakia and to compare the results with histopathological examination.Study designA total of 50 patients with leukoplakia were included from the outpatients attending the Department of Oral Medicine and Radiology, Dental Hospital, Bengaluru, Karnataka, India. These patients were subjected to conventional oral examination followed by chemiluminescent examination with Vizilite (Zila, Fort Collins, CO, USA) and biopsy for histopathological confirmation.ResultsThe sensitivity, specificity, positive predictive value, and negative predictive value of chemiluminescence were 93.75%, 55.56%, 78.95%, and 83.3%, respectively. The overall accuracy of chemiluminescence was 80%. A statistically significant association was observed between histopathology results and chemiluminescence results.ConclusionAlthough it is an easy, safe, minimal time consuming, and noninvasive technique, it has only adjunctive utility and it does not replace biopsy for the diagnosis of leukoplakia.     

Electrodeposition of bilayers of dithiols

We report an electrochemical method to form a bilayer of dithiol. The cyclic voltammogram of the oxidative deposition of an aromatic dithiol on gold from an alkaline aqueous solution reveals two current peaks separated by more than 400 mV. The integrated charge of the oxidative current peak (B) at the most positive potential is twice that of the other oxidative current peak (A). These two oxidative current peaks were characterized by differential capacitance and electrochemical quartz crystal microbalance (EQCM) measurements. A decrease of the capacity by a factor of two, and an increase of the EQCM frequency change by a factor of two were observed when the potential was scanned from a value where only the first oxidative peak (A) is obtained, to a potential where both oxidative current peaks (A and B) are obtained. Infrared spectra show that the aromatic dithiols adsorb vertically at potentials corresponding to the current peak A and they become tilted for potentials corresponding to the current peak B. The simple relationships between the properties of the two oxidative current peaks are found to be compatible with a step-wise oxidative deposition of a bilayer of dithiol.     

正常青年Monson球面半径的测量研究

目的测量正常青年Monson球面半径。方法选择60名(男30名,女30名)正常青年制取全口印模,应用立体摄影成像的原理与方法对Monson球面半径进行测量和统计学处理。结果Monson球面的半径平均为10.173 cm,大于理论值10.160 cm,差异有显著性(P<0.01);男、女性球面半径差异无显著性。结论本实验所得到的数据可作为全口义齿修复中记录颌位关系的一个参量。     

The effects of oral administration of chlorhexidine on the rate of regeneration of epithelia of the oral mucosa and skin of mice

Using injection of tritiated thymidine and autoradiography, the labelling index, rate of migration of labelled cells and width of epithelia of the oral mucosa and skin of mice was examined after either (a) 2 % chlorhexidine solution or (b) distilled water, was instilled twice daily for 7 days into the oral cavity. A small but consistent reduction in the rate of regeneration of epithelia in chlorhexidine-treated animals was attributed to the added stress to which the experimental group was exposed. It was anticipated that a direct irritant effect of chlorhexidine on the oral mucosa would produce a locally increased rate of epithelial regeneration: no such change was observed. No change in the labelling index of the liver or in the rate of gain of weight in experimental animals was detected during the experimental period.     

A profile of organizational characteristics of colleges of dentistry

This study investigated the organizational characteristics of colleges of dentistry as perceived by their deans, associate deans, and department chairs. Likert's Profile of Organizational Characteristics is used to describe the administrative structures of the colleges on a continuum from exploitive/authoritative through benevolent/authoritative and consultative to participatory. In addition, administrators were asked to evaluate their colleges' effectiveness in adapting to an environment of change. The results indicate a relatively low level of participation in administration in contrast to a high desire for participation, and that administrators believe their colleges are only marginally effective in adapting to change.     

颌骨动静脉畸形的栓塞治疗

目的：总结直接穿刺结合经血管内介入栓塞治疗颌骨动静脉静脉畸形的经验。方法：收治凳骨动静脉畸形患者6例,均进行了介入栓塞治疗。采用的栓塞材料为附凝血棉纤毛的螺圈,聚乙烯醇泡沫微粒和二氰基丙烯酸对丁酯。数字减影颈动脉造影在PHILIPSV300下完成。结果6例颌骨动静脉畸形患者中4,例急性出血得到了快速、有效控制,1例慢性渗血的右下 骨动静脉畸形患者,介入栓塞治疗,拔除松动的右下凳第一磨牙,有效地控制了出血,另1例伴局部软组织搏动性膨隆的上凳骨动静脉畸形患者,介入治疗后膨隆的搏动性得到明显改善,栓塞治疗后分别随访3－24个月,均未发现有口腔内渗血或出血。随访的X线片上,病灶区可见新骨形成。结论：局部穿刺结合经血管内介入栓塞治疗颌骨动静畸形是一种安全、有效的治疗方法。     

Development of a specific indicator of the well-being of wearers of removable dentures

Montero J, Bravo M, López‐Valverde A. Development of a specific indicator of the well‐being of wearers of removable dentures. Community Dent Oral Epidemiol 2011; 39: 515–524. © 2011 John Wiley & Sons A/S Abstract – Objectives: Bearers of removable prostheses have certain particular characteristics that require the inclusion of items able to detect the specific effect on their oral functions (derived from the presence of such prostheses). We aimed to develop and validate a specific indicator for the assessment of oral health–related quality of life in bearers of dentures. Methods: A panel of experts compiled a questionnaire addressing oral health–related quality of life (11 items) to assess the degree of well‐being afforded by removable dentures. After a pilot trial in patients bearing prostheses (n = 36), a consecutive sampling of denture wearers (n = 123) was conducted among patients not requesting odontological treatment and accompanying persons, attending their respective health centres in the City of Granada and its metropolitan area. The subjects were classified as RPP1 (removable partial prosthesis on one of the arches, RPP2 (on both) and complete prosthesis (CP on both arches). Results: The questionnaire was consistent (Cronbach alpha 0.814) and proved to have suitable validity. Factor analysis revealed three factors termed physical, psychological and social well‐being, which coherently supported the interrelationship among the 11 items. The prevalence of impact was significantly higher in the CP individuals (97.1%) and in that of the RPP2 group (92.1%) than in the RPP1 subjects (80.7%). Prosthetic fit, aesthetics and self‐confidence were significantly discrepant among the prosthetic groups, although the total prosthetic quality of life score was not able to differentiate them. The main prosthetic impact in all the prosthesis‐wearing groups was attributed to ‘food impaction’, although all the groups were essentially satisfied with their mouth. Conclusions: The prosthetic quality of life (PQL) questionnaire is a valid and reliable indicator of the specific well‐being of partial or complete denture wearers.     

Estimating the location of the center of resistance of canines

Objective:To develop a method to quickly estimate the location of center of resistance (CR) in mesial-distal (MD) and buccal-lingual (BL) directions from the tooth''s image.Materials and Methods:The maxillary cone-beam computed tomography (CBCT) scans of 18 patients were used. Finite element (FE) models of the canines and their surrounding tissues were built based on their CBCT scans to calculate the locations of CR. Root length, centroid of the contact surface (CCS), and centroid of projection of the contact surface (CPCS) were also obtained from the images. The CCS and CPCS locations were projected on the tooth''s long axis, which were represented as percentages of the root length measured from the root''s apex.Results:Using the FE results as the standards, the errors of using CCS or CPCS to estimate CR were calculated. The average location of CR calculated using the FE method was 60.2% measured from the root’s apex in the MD direction and 58.4% in the BL direction. The location of the CCS was 60.9%. The difference in CR was 0.7% in the MD direction and 2.5% in the BL direction. The location of CPCS was 60.2% in the MD direction and 59.1% in the BL direction, which resulted in a 0.1% and 0.8% difference with the reference CR, respectively. The average difference of CR in the MD and BL directions was small but statistically significant (P < .05).Conclusion:The locations of the CR of a human canine in the MD and BL directions can be estimated by finding the CPCSs in those directions.     

Correlation of types of orbital fracture and occurrence of enophthalmos

We sought to investigate the correlation between type of orbital fracture and occurrence of traumatic enophthalmos. The 119 patients with orbital fractures were divided into the enophthalmos group (71 cases) and the nonenophthalmos group (48 cases). The 2 groups were compared by location and type of orbital fracture based on observation of computed tomography scans. We found the incidence of medial wall fractures significantly higher in the enophthalmos group (76.06%) than in the nonenophthalmos group (22.92%, χ(2) = 32.63, P < 0.05). The incidence of combined medial-inferior wall fractures was also significantly higher in the enophthalmos group (52.93%) than in the nonenophthalmos group (12.5%, χ(2) = 23.21, P < 0.05). However, the incidence of lateral-inferior wall fractures was significantly lower in the enophthalmos group (36.62%) than in the other group (58.33%, χ(2) = 4.11, P < 0.05). In most cases of lateral-inferior orbital wall fracture in the enophthalmos group, the zygomatic complex was displaced toward the lateral-posterior direction. The combined medial-inferior wall fracture is likely the primary type of multiple wall fracture leading to traumatic enophthalmos. Enophthalmos caused by a combined lateral-inferior fracture may be correlated with lateral-posterior displacement of the zygomatic complex.     

瓷层厚度对金瓷修复体颜色的影响

目的 探讨瓷层厚度对金瓷修复体颜色的影响。方法 选用VMK 95 METALL KERAMIK,A2色瓷粉,Ni-Cr非贵金属体系烤瓷合金(德国),常规制作金瓷试件(金属基底厚为0.3mm,瓷厚度分别为0.5mm,1.0mm,1.5mm,2.0mm,2.5mm各10个试件,分成5组)。用Shade eye EX(松风,日本)电脑比色仪检测试件的颜色。结果 ①不同瓷层厚度,其金瓷修复体的颜色、色相、彩度和明度均不同,并有显著差异(P<0.01)。②随着瓷厚度的增加,试件颜色有从A2→A1的变化趋势;试件的色相有从R1→R2的变化趋势;试件的彩度值和明度值均变小。结论 瓷层厚度太大或太小都会影响金瓷修复体颜色,最佳瓷厚度为(1～2.5mm)。由于Vita Lumin比色板与中国人牙色相比,颜色分布不均匀,如要减少颜色的明度或彩度,可适当增加瓷厚度以弥补Vita Lumin比色板的局限。     

Preparation of bone tissue of the jaw to implantation of abutment elements of dentures

A complex multi-staged method for stimulation of bone tissue regeneration in the jaws after removal of teeth and preparation of bone tissue for subsequent implantation, stimulation of bone tissue regeneration after implantation, and adaptation of bone tissue of the jaws to masticatory pressure is developed. The method is based on utilization of magnetic laser exposure with a universal Optodan laser device. In case of pronounced inflammation and pyodestructive processes after implantation, these processes are liquidated due to detoxifying effect of the blood, which is stimulated by irradiation of the carotid sinuses on both sides. Granulation tissue round the heads of implants is removed by laser coagulation with surgical lasers Lancet or Stokos.