Combined effects of electric toothbrushing and dentifrice on artificial stain removal: An in vitro study.

BACKGROUND: This in vitro study aimed to clarify the combined effect of electric toothbrushing and dentifrice on the removal of artificial stain. MATERIAL AND METHODS: Twenty-five bovine incisors were cut at the cervix and the crown was embedded in auto-cured acrylic resin. Specimens were abraded using #240 SiC paper to obtain a flat enamel surface, and 20 specimens were treated with 10% citric acid / 3% ferric chloride solution followed by 1% tannic acid solution to produce surface staining. They were divided into four groups: 1) brushing with an electric toothbrush and whitening dentifrice (group S+B); 2) brushing with an electric toothbrush and fluoride dentifrice (group S+C); 3) brushing with an electric toothbrush and no dentifrice (group S); and 4) no brushing (control group). The remaining five specimens were used as a baseline. Color values (L*, a*, and b* were measured before brushing (0 min), and at 1 min, 5 min, 10 min, and 20 min using a microscopic area spectrophotometer. The color change (ΔE) was calculated by subtracting the baseline values from the final color values obtained at each time point. The data were statistically analyzed using two-way repeated-measures analysis of variance and Tukey's honest significant difference test as a post hoc test (p<0.05). RESULTS: The L* values of groups S+B and S+C increased over time (p<0.05), but no significant differences were observed in group S and the control group at any of the time points (p>0.05). Groups S+B and S+C demonstrated greater ΔE values than group S. CONCLUSIONS: The combination of electric toothbrushing and dentifrice removed the artificial stain more effectively than brushing without dentifrice. However, the stain removal was limited. The two dentifrices evaluated in this study exhibited similar stain removal effects. Key words:Color change, stain removal, dentifrice, electric toothbrush, whitening effect.

Effect of professional dental prophylaxis on the surface gloss and roughness of CAD/CAM restorative materials.

BACKGROUND: This study aimed to evaluate the effect of dental prophylaxis on the surface gloss and roughness of different indirect restorative materials for computer-aided design/computer-aided manufacturing (CAD/CAM): two types of CAD/CAM composite resin blocks (Shofu Block HC and Estelite Block) and two types of CAD/CAM ceramic blocks (IPS Empress CAD and Celtra DUO). MATERIAL AND METHODS: After polishing the CAD/CAM blocks and applying prophylaxis pastes, professional dental prophylaxis was performed using four different experimental protocols (n = 5 each): mechanical cleaning with Merssage Regular for 10 s four times (Group 1); four cycles of mechanical cleaning with Merssage Regular for 10 s and Merssage Fine for 10 s (Group 2); four cycles of mechanical cleaning with Merssage Regular for 10 s and Merssage Fine for 30 s (Group 3); and mechanical cleaning with Merssage Fine for 10 s four times (Group 4). A glossmeter was used to measure surface gloss before and after mechanical cleaning, and a contact stylus profilometer was used to measure surface roughness (Ra). RESULTS: Polishing with prophylactic paste led to a significant reduction in surface gloss and increase in surface roughness among resin composite blocks, whereas the polishing-related change in surface gloss or roughness was smaller in Celtra DUO, a zirconia-reinforced lithium silicate block. CONCLUSIONS: Changes in surface gloss and roughness due to polishing with a prophylactic paste containing large particles were not improved by subsequent polishing with a prophylactic paste containing fine particles. Key words:CAD/CAM, professional dental prophylaxis, prophylactic paste, surface gloss, surface roughness.

Correlations between Perceived Oral Malodor Levels and Self-Reported Oral Complaints.

Objectives. Even though objective data indicating the absence of oral malodor are presented to patients, they may be skeptical about the results, possibly due to the presence of some discomfort in the oral cavity. The objective of this study was to investigate whether there is an association among self-perceptions of oral malodor, oral complaints, and the actual oral malodor test result. Materials and Methods. Questions concerning self-perceptions of oral malodor and subjective intraoral symptoms were extracted from a questionnaire on oral malodor completed by 363 subjects who visited the clinic for oral malodor of Tokyo Dental College Chiba Hospital and gave consent to this study. In addition, the association of self-perception of oral malodor with values obtained after organoleptic and OralChroma measurement was analyzed. Results. No correlation between 195 subjects (54%) who were judged "with oral malodor" (organoleptic score of ≥1) and 294 subjects (81.6%) who had a self-perceptions of oral malodor was observed. Self-perception of oral malodor was significantly correlated with tongue coating (p = 0.002) and a strange intraoral taste (p = 0.016). Conclusions. Subjects with a self-perception of oral malodor were not necessarily consistent with those actually having an oral malodor. In addition, it was suggested that patients became aware of oral malodor when they felt oral complaints.

Personality traits in patients with oral malodor.

Many patients presenting at oral malodor clinics have psychological halitosis, which is characterized as being obsessive about having oral malodor or being distressed from a keen awareness of oral odor. We used the Tokyo University Egogram (TEG) to evaluate personality traits in patients presenting at the oral malodor clinic of this institute. The incidence of each TEG personality type was compared between a total of 600 patients presenting at the clinic and a cohort of healthy individuals. Differences were found between the malodor patient and healthy groups. Nurturing Parent (NP)-dominant, Adult (A)-dominant, inverse N (NP low, Free Child high), showed a significant decrease of 6.7, 11.3, and 3.6%, respectively; whereas N (A low) and N (NP high, Free Child low) showed a significant increase of 3.3 and 6.4%, respectively (p < 0.01).

Influence of different rubber dam application on intraoral temperature and relative humidity.

The purpose of this study was to investigate the effect of type of rubber dam and application method on the moisture exclusion effect. The intraoral temperature and relative humidity were compared among various moisture exclusion appliances. Various dry field techniques were applied to 5 subjects and intraoral temperature and relative humidity measured 5 min after placing a digital hygro-thermometer in the mouth. The relative humidity was 100% in all subjects when moisture was excluded by means of cotton rolls alone. When only tooth 36 was exposed, relative humidity was significantly lower with latex, urethane, or 3-dimensional sheets than with cotton rolls alone, and was similar to the level of humidity in the room. When a local rubber dam was used, the relative humidity was significantly higher than the indoor humidity (p<0.05). No significant differences were noted in the intraoral temperature or relative humidity between exposure of 4 teeth and 1 tooth, but variation in the relative humidity was more marked in 4- than in 1-tooth exposure. The creation of an air vent did not influence the moisture exclusion effect. These results suggest that the rubber dam isolation technique excludes moisture to a level equivalent to the humidity in the room when only a single tooth is exposed, but the moisture exclusion effect may be inconsistent when several teeth are exposed.

Analysis of dental treatment performed by dental residents at General Dentistry Department of Tokyo Dental College Chiba Hospital over 6 years following introduction of mandatory dental clinical training system.

Six years have passed since the introduction of legislation mandating at least 1 year of clinical training for those who have passed the national dentist examination. To determine whether clinical training has been appropriately implemented at the General Dentistry Department of Tokyo Dental College Chiba Hospital, a managed-type clinical training facility, the number of patients treated and types of dental and dental technical work performed by dental residents trained by the department were summarized and analyzed. The number of patients treated per dental resident increased from 11 in 2006 to 15 in 2011. By treatment type, periodontic treatment was the most frequently performed throughout the study period, followed by endodontic treatment. Conservation treatment, prosthodontic treatment with crowns/bridges, and prosthodontic treatment with dentures were performed at a similar moderate frequency, while oral surgical treatment was performed least frequently throughout the study period. The frequency of periodontic treatment increased slightly, whereas that of endodontic treatment decreased slightly or remained almost unchanged after introduction of the mandatory clinical training system. When the distribution of dental treatment performed at our department was compared with that of dental treatment performed by general dentists across Japan in 2011, our department showed a slightly lower frequency of periodontic treatment and higher frequency of endodontic treatment than the national total, whereas the frequency of other types of treatment was similar between the two populations. These results demonstrated that appropriate clinical training has been provided by our department to meet the purpose of offering dentists the opportunity to acquire the basic diagnostic and treatment abilities that would enable them to provide appropriate treatment for injuries and diseases frequently encountered in daily practice. The study also revealed some problems, such as a decreasing number of residents engaging in dental technical work each year. For additional improvement in the quality of dental clinical training, more analyses are needed to further identify and address potential problems in the system.

Recent trends among dental residents at Tokyo Dental College.

Trends among dental residents at Tokyo Dental College between 2006, at which time clinical residency became mandatory, and 2011 were analyzed and the following results obtained. Almost all the eligible students from our school participated in the orientation seminar on dental residency programs. Although the number varied slightly by year, approximately 70 to 150 students from other schools also participated in these orientation seminars. Almost all the students from our school and 60 to 80% of those from other schools participating in the orientation seminar each year applied to sit the dental residency entrance examination. The number of candidates was highest in 2006 (318) and lowest in 2010 (205) (average: 248), and the applicant-to-seat ratio for residency was 1.59. The examination pass rate was 59.02%. Approximately 10% of the students from other schools were admitted as dental residents.

Effects of position and task demands on endogenous eyeblink.

The present study investigated the effects of the supine position and task demands on blink activities. 24 participants (M age = 21.7 yr., SD = 0.5) performed the Japanese version of the Reading Span Test to investigate the effects of task difficulty. Eyeblink activities were detected by electrooculogram, via a wireless system, and were analyzed using newly developed software. Results showed that the supine position did not affect blink rate itself, but some wave characteristics of blinks, such as blink amplitude and closing and re-opening duration, were influenced; specifically, amplitude was reduced and durations increased. Further analyses suggested that task demands affected eyeblink rates but did not affect waveform attributes. Eyeblink rates increased during task performance and decreased during rest periods but it was not confirmed that this task demand effect was larger in the supine position than in the sitting position.

Character traits of malodor patients.

Many patients visit oral malodor clinics because of malodors which are brought to their attention by friends and family, or because they note the behavior of people around them, they suspect a problem and develop a fear of having an oral malodor. However, only around 30% of such patients actually have levels of malodor high enough to bother other people. Many patients exhibit halitophobia symptoms, which present as self-perception of malodor, and thus have a strong obsession about their smell which results in distress. Here, we carried out a study on 300 outpatients who visited the Tokyo Dental College Chiba Hospital Odor Clinic. We used the Tokyo University Egogram (TEG) to elucidate character traits of affected outpatients and compared the occurrence of TEG types in these patients with those of normal individuals. We discovered that 10.4% of patients were A-dominant type, which was 10.6% lower than the 21.0% of normal individuals. On the other hand, 18.4% of patients were N-type (NP high, FC low), which was 9.9% higher than the 8.5% of normal individuals. Results revealed that very few of the malodor outpatients exhibited the trait that shows intelligence, calm judgment, and self-affirmation, and as a result enjoy their life. Instead, many of these patients tended to show high levels of kindness and appeared to be holding themselves back and exercising patience.

Matching system within clinical training facilities group of clinical dental training in Tokyo Dental College Chiba Hospital.

Since clinical dental training became mandatory in April 2006, Tokyo Dental College Chiba Hospital has been offering the following two types of training system: 1. a single system, and 2. a clinical training facilities group system. The clinical training facilities group system consists of program B, in which residents are trained in a cooperation-type clinical training facility for 3-4 months, and program C, in which residents are trained in two cooperation-type clinical training facilities for 7-8 months. A matching system within the clinical training facilities group is applied to select and decide on the cooperation-type clinical training facility for residents. In this system, the ranking of resident candidates that a cooperation-type clinical training facility would like to accept, and the ranking of training facilities that candidates choose are matched. The present study investigated the matching system within the clinical training facilities group in 2006, 2007, and 2008. The rate of matching to their third choice was more than 90% in program B and about 80% in program C in each year, suggesting a high matching rate. The percentage of cooperation-type clinical training facilities accepting dental residents dropped due to a decrease in the number of such residents. The distribution of accepted cooperation-type clinical training facilities is concentrated in Chiba Prefecture where our hospital, the management-type clinical training facility, is located, and the neighboring prefectures.

Clinical usefulness of "Isolite Plus" for oral environment of Japanese people.

The recent demand for dental devices which are easier to handle and offer higher levels of reliability and safety has led to the development in the US of Isolite Plus, a new oral support device. When placed in the oral cavity, Isolite Plus enables marking of the surgical field, secures the treatment space, ensures a vacuum, protects the cheek and tongue, assists in opening the mouth, prevents accidental ingestion/aspiration, ensures treatment without contamination and enhances comfort and safety during dental treatment. The present study was carried out to verify whether Isolite Plus can fit well in the mouth of Japanese people and to determine whether it performs adequately. Thirty resident dentists were required to wear Isolite Plus in their mouth and perform mutual simulation training using an air turbine handpiece. After the training, both subjects playing the role of surgeon and those playing the role of patient were asked to complete questionnaires. On the basis of the results, we discuss the clinical usefulness of Isolite Plus in Japanese people. In the present investigation, Isolite Plus was rated slightly better by surgeons than by patients. The supportive functions of the device were judged inadequate due to the poor fit of the mouthpiece portion of the device to subjects' mouth. For the distribution of Isolite Plus in the Japanese market, the mouthpiece portion of the device should be improved so that it can fit the mouth of Japanese people.

Clinical care provided on post-graduate dental clinical training course at Tokyo Dental College Chiba Hospital, Department of General Dentistry.

Number of patients assigned to dental residents, course of treatment and number of various technical tasks performed as described in the Reports on Clinical Training of Dentists published by the Department of General Dentistry, Tokyo Dental College Chiba Hospital since its establishment in 2002 were compared between before (2003-2005) and after (2006-2007) clinical training was made mandatory, and the state of clinical residency evaluated. Number of patients assigned generally increased, and mean number of patients treated by each resident in 2007 (15.08) was approximately 2 times higher than that in 2003 (8.47). Total number of treatments was 1.38 times higher in 2007 than in 2003, and periodontal treatment accounted for approximately 40% of all treatment both before and after clinical training became mandatory. Number of technical tasks in 2004-2007 was less than half the peak in 2003. To further improve clinical training, evaluation and implementation of effective approaches is necessary to secure an adequate number of patients, widen the variety of cases and increase the number of technical tasks.

Clinical training in department of general dentistry at Tokyo Dental College Chiba Hospital.

A compulsory postgraduate clinical training program was established in April 2006 in Japan, and an applicants-only postgraduate training program 9 years ago at Tokyo Dental College. In addition, a training program was also established in the Department of General Dentistry at Tokyo Dental College Chiba Hospital in April 2002. The curriculum consists of training in the outpatient clinic and the following: 1) clinical training (preparation of written treatment plans, simulation practice, submission of evaluation sheets, and submission of training journals), 2) tutorials, and 3) case reports. In 1), trainees write treatment plans for new patients, discuss them with their instructor, perform simulation practice using dummies based on those discussions, submit evaluation sheets and training journals concerning treatment, and receive their instructor's assessment. In 2), trainees are divided into small groups, independently study themes they have chosen, and present the results. In 3), they orally report cases they have treated and receive evaluation by other trainees and instructors in general discussion meetings. In addition, a course was also established at the Department of General Dentistry, Tokyo Dental College Chiba Hospital in April 2002. We report the training curriculum of this course.