The relationship between oral Candida carriage and the secretor status of blood group antigens in saliva

OBJECTIVE: The aim of the study was to investigate the relationship between oral Candida carriage and the secretor status of blood group antigens. STUDY DESIGN: Unstimulated whole saliva and oral rinse samples were obtained from 180 healthy subjects. These samples were plated on Sabouraud's dextrose agar media to determine oral Candida carriage. Sodium dodecylsulfate polyacrylamide gel electrophoresis and immunoblotting were performed on whole saliva samples to determine the secretor status of blood group antigens. RESULTS: The oral Candida carriage rate was found to be 45.0%. The sensitivity of the concentrated rinse culture proved to be superior. Oral Candida carriage was not significantly related to the blood group or secretor status of ABH or Lewis antigens. No significant relationship was found between oral Candida carriage and salivary flow rate. However, smoking affected oral Candida carriage. CONCLUSION: Oral Candida carriage in healthy individuals is not significantly related to blood group or secretor status.     

Effects of sealing the perforated sinus membrane with a resorbable collagen membrane: a pilot study in humans

The effects of repairing the perforated sinus membrane with collagen membrane are unknown. The purpose of this pilot study was to clinically, histologically, and histomorphometrically evaluate the results of repairing the perforated sinus membrane with resorbable collagen membrane. A split-mouth design was followed in the current study. Five subjects requiring bilateral sinus grafting were included in the study, where one site was accidentally perforated during sinus augmentation procedures and the other site was not perforated. The perforated sites were repaired with a resorbable collagen membrane. Dental implants were placed at a second stage and biopsies were harvested from both sinuses. New bone formation was measured for all sites. Implant survival was recorded at second-stage surgery. Nonperforated sites demonstrated significantly more bone formation (34.40%) than perforated sites (12.80%) (P = .016). Implant survival at second-stage surgery was significantly inferior in perforated sites (54.5%) when compared with nonperforated sites (100%) (P = .0146). The study demonstrated that perforation and repair of the Schneiderian membrane can compromise new bone formation and implant survival rate.     

A survey of deans: trends, challenges, and mentoring in prosthodontics. Part 2.

PURPOSE: This study consists of two parts. Part 1, a survey of program directors, was conducted to examine current trends in advanced education in prosthodontics in the United States. Part 2 reports on the findings of a survey distributed to the deans of US dental schools to evaluate their observations of trends in prosthodontic education. MATERIALS AND METHODS: A national, electronic survey of 55 dental school deans was distributed by e-mail to evaluate an interest in specialty training, an interest in specialization in prosthodontics, faculty shortages, programs to address faculty shortages, predoctoral curriculum in prosthodontics, opinions regarding dental specialties, and the administrative position of prosthodontics within the schools. RESULTS: Of the 55 deans, 44 deans responded, an 80% response rate. Only five deans reported a decrease in the number of students seeking specialty training after dental school. The remaining 39 deans reported a large increase, slight increase, or no change in those seeking specialty training. In 29.6% of the deans' responses, an increased interest in prosthodontics was reported, whereas 16 deans reported no change in the level of interest. One or more open faculty positions in prosthodontics existed at 29 dental schools, and 28 schools offered at least one incentive or a variety of incentives to recruit faculty. The respondents to the deans' survey revealed predoctoral student exposure to prosthodontists was high, and exposure to postgraduate prosthodontics students was low. A survey of internal school programs that might have an impact on an increased interest in prosthodontics revealed the presence of a predoctoral mentoring program for prosthodontics in 80% of the institutions. The clinical curriculum included treatment of a variety of cases, including complex cases as defined by a diagnostic classification system. The response to whether dental specialties should be combined or remain individual provided some interesting data. Only 40.9% of the deans responded that prosthodontics was a separate department. CONCLUSION: Dental school deans reported an increased interest in specialty training. Predoctoral student exposure to prosthodontics was high due to the nature of their clinical experience and due to the exposure to full-time prosthodontics faculty. Many dental schools have programs, such as mentoring and new technology, which might have an impact on predoctoral students' increased interest in prosthodontics.     

Ganglion cyst of the temporomandibular joint

We report a case of cystic lesion in a 37-year-old woman. The patient had an oval-shaped lesion adjacent to the temporomandibular joint. Thick fibrotic tissue and muscle were observed microscopically, but the epithelium lining was not observed. The lesion was diagnosed as a ganglion cyst. The patient's general medical history was non-contributory. High performance liquid chromatography (HPLC) and mass spectrophotometry (MS) revealed some proteins from the fluid in the lesion, such as a filaggrin precursor, dystroglycan, a polyprotein of the hepatitis C virus, and proteins originating from bacteria. The follow-up examinations revealed no recurrence. The probable pathogenesis of the lesion is discussed.     

Root canal shaping with manual stainless steel files and rotary Ni-Ti files performed by students

AIM: To investigate root canal shaping with manual stainless steel files and rotary Ni-Ti files by students. METHODOLOGY: Two hundred and ten simulated root canals with the same geometrical shape and size in acrylic resin blocks were prepared by 21 undergraduate dental students with manual stainless steel files using a stepback technique or with rotary Ni-Ti files in crown-down technique. Preparation length, canal shape, incidence of fracture and preparation time were investigated. RESULTS: Zips and elbows occurred significantly (P < 0.001) less frequently with rotary than with manual preparation. The correct preparation length was achieved significantly (P < 0.05) more often with rotary Ni-Ti files than with manual stainless steel files. Fractures occurred significantly (P < 0.05) less frequently with hand instrumentation. The mean time required for manual preparation was significantly (P < 0.001) longer than that required for rotary preparation. Prior experience with a hand preparation technique was not reflected in an improved quality of the subsequent engine-driven preparation. CONCLUSIONS: Inexperienced operators achieved better canal preparations with rotary Ni-Ti instruments than with manual stainless steel files. However, rotary preparation was associated with significantly more fractures.     

Comparison of apical transportation in four Ni-Ti rotary instrumentation techniques

A new radiographic technique was used to compare apical transportation in four Ni-Ti rotary instrumentation sequences. Mesiobuccal canals of 60 extracted mandibular molars were randomly divided into four groups. Groups 1 and 3 were instrumented by crown-down and groups 2 and 4 by step-back technique with 0.06 ProFiles series 29 to size 6. In groups 3 and 4 Greater Taper files were first used in a crown-down manner. The central axes of initial and final instruments were radiographically superimposed to measure loss of working length (WL) and transportation at 0, 0.5, 1, 3, and 5 mm from WL. ANOVA test showed no significant differences among groups regarding degree of transportation or loss of WL. Transportation was negatively correlated with radius of curvature at 0.5 and 5 mm from WL. The results indicate that the operational sequence of ProFiles or preinstrumentation with GT files has no effect on degree of transportation and loss of WL.     

Determinants of successful treatment of bimaxillary protrusion: orthodontic treatment versus anterior segmental osteotomy

The purpose of this study was to investigate the differences in initial skeletal, dental, and soft tissue characteristics of bimaxillary protrusion (BP) patients to determine poor or good results with orthodontic treatment (OT) or anterior segmental osteotomy (ASO) with extraction of four first premolars. Lateral cephalometric radiographs of 46 adult Korean females with BP were analyzed before treatment (T0) and after treatment (T1). According to the measurements at T1, patients were classified into group 1 (poor result with OT, n = 12), group 2 (good result with OT, n = 11), group 3 (poor result with ASO, n = 5), and group 4 (good result with ASO, n = 18). Sagittal, vertical, dental, and soft tissue variables were measured. The differences at T0 among the four groups were compared by one way analysis of variance test and verified by Scheffe's multiple comparison test. Stepwise discriminant analysis was performed to find decisive predictors. Skeletal class II malocclusion tendency, less developed chin, and vertical facial growth pattern were related with group 1. Overly uprighted and less protrusive upper and lower incisor, near normal interincisal angle (IIA), less protrusive upper lip, and more obtuse lower nasolabial angle (NLA) were related with group 3. IIA, U1-NA distance, combination factor, interlabial gap, lower NLA, pterygomaxillary fissure-N, and posterior nasal spine-anterior nasal spine were selected as significant variables for discriminating the four groups. The percentage of correctly classified cases was 91.3%. In particular, the discriminant function showed the highest accuracy in the prediction of group 4. These variables and discriminant functions contributed to the differential diagnosis on BP to make a procedural decision between OT and ASO.     

Effects of sonicated Enterococcus faecalis extracts on interleukin-2 and interleukin-4 production by human T cells

In the present authors' previous study, sonicated Enterococcus faecalis extracts were shown to suppress the cell cycle progression of human lymphocytes. To study the effect of this microorganism on the function of lymphocytes, the authors investigated the levels of interleukin-2 (IL-2) and interleukin-4 (IL-4) production by T lymphocytes before and after the addition of sonicated E. faecalis extracts. In this study, levels of IL-2 and IL-4 produced from T cells were evaluated by using the quantitative sandwich enzyme immunoassay technique. In response to phytohemagglutinin (PHA) stimulation, T cells produced increased levels of IL-2 and IL-4. However, the expressions of both cytokines were significantly inhibited when PHA-activated T cells were preexposed to 12.5 microg/ml and 25 microg/ml of sonicated E. faecalis extracts (p < 0.05). This effect was concentration-dependent, because the levels of IL-2 and IL-4 expressions were not affected by the addition of a low concentration (5 microg/ml) of sonicated extract. These findings suggest that Th1 and Th2 immunosuppression mediated by E. faecalis could be a part of the pathogenic mechanism of the endodontic failure associated with this microorganism.