Conversion of plaque-area measurements to plaque index scores. An assessment of variation and discriminatory power.

Plaque areas recorded graphically or photographically provide a permanent record of plaque accumulations on teeth at a moment in time. As such, these records could be re-evaluated and converted into other index scores. The purpose of this study was to determine the reproducibility of scoring a plaque index from previously recorded plaque areas and to compare such scores with the original scores of the same index. A randomised blind, crossover study comparing 5 treatments for plaque inhibition scored by plaque area and index was chosen. 2 examiners, the original scorer PRH and another, NC, 2x scored the plaque area tooth charts according to the criteria of the plaque index system used in the original study. Standard deviations of the differences showed intra-examiner repeatability to be high particularly for the original examiner. Inter-examiner reproducibility for the original index scores was considered good but less than for intra-examiner repeatability. Correlation coefficients were complimentary to the differences analysis, being very high within examiners and less high for between examiners and original and rescored index. Separation between distributions of plaque area measurements for consecutive values of the index were particular good for scores 2 versus 3 and 3 versus 4 and less good for 1 versus 2 and 4 versus 5. Reanalysis of the study for treatment differences using rescored data revealed a similar level of significance as using the original data. Rescored index had similar discriminatory power for the study as plaque area and original plaque index when both were derived from the same buccal tooth surfaces. However, discriminatory power was less by comparison with original plaque index derived from the buccal surfaces of all teeth. It is concluded that plaque area provides a permanent record of plaque distribution which can be converted into index data at a later date. Such data collection could make possible comparisons between studies using different indices.

An in vitro assessment of the dentine lost during instrumentation using the Periosonic system.

This study investigated the ability of a new instrument designed for root debridement, the Periosonic, to remove dentine compared to a hand curette and an ultrasonic scaler. The Periosonic system is a modification of the Micro-Megax endodontic system and uses modified files to remove plaque, calculus and tooth substance. The Periosonic has 2 file types; the Periosonic 1 is a more aggressive file for the removal of gross supra- and subgingival deposits, while the Periosonic 2 is a thinner more flexible file used for the removal of subgingival deposits. 40 human dentine specimens were ground flat and baseline measurements were made using a surfometer. The specimens were divided into 4 experimental groups and each group was treated with a hand curette, ultrasonic scaler, Periosonic 1 or 2 using 12, 1-s strokes. The specimens were remeasured blind in the surfometer. The curette removed 23.6 microm of dentine, the ultrasonic 6.8 microm, the Periosonic 1 18.8 microm and the Periosonic 2 12.5 microm. A qualitative assessment of the samples following mechanical preparation was also made. In conclusion, the Periosonic instrument does not remove more tooth substance than a conventional curette and may be a useful addition for the debridement of root surfaces.

Home use oral hygiene product trials; timing of the last brushing before scoring; an assessment of variation.

Home use studies to evaluate oral hygiene products often standardise the time lag between plaque scoring and the previous toothbrushing. Most protocols have favoured an evening before brushing regimen, but the rationale and even the validity of this approach has not been evaluated. In this study, a group of 30 adult subjects participated in a 4-period randomised single-blind crossover evaluation of within-subjects and between-subjects variation in plaque levels after two different brushing times. Thus, on 2 occasions, plaque was scored after an "evening before" brushing and on the other 2 occasions plaque was scored after a "morning before" brushing. As expected, mean plaque levels were lower after morning brushing, but only by 11%. There was little difference for lingual plaque (4%) but a greater difference for buccal plaque (18%). Comparisons for within-subjects variation, which ideally should be low, favoured morning brushing but differences were small and not significant. Comparisons for between subjects variation, which ideally should be high to permit discrimination between high and low plaque formers, also favoured morning brushing but were only significant for lingual plaque. Intraclass correlation coefficients of reliability revealed that overall repeatability was high for both morning and evening regimens; marginally favouring morning brushing. Analyses using all four scores per subject disregarding timing of brushing increased within subjects variation and decreased repeatability, particularly for buccal plaque. In conclusion, the data support the concept of standardising the time between plaque scoring and the previous tooth-brushing. There were no clear statistically significant grounds for preferring one brushing regimen to the other, however the data favoured the morning brushing.

The oral hygiene and gingival health of paraplegic inpatients--a cross-sectional survey.

Physical and/or mental handicaps are known to directly or indirectly compromise hygiene habits including oral hygiene. It is recommended that handicapped patients, their parents or care workers require from an early stage dental health education and active involvement in preventive programmes. This study surveyed the oral hygiene of paraplegic patients in a specialised centre to determine their oral hygiene needs. Most patients had moderate to poor oral hygiene and gingivitis was prevalent and severe. Plaque and gingivitis was increased in quadriplegic compared to hemiplegic patients. The data indicate that as part of rehabilitation of paraplegic patients there is a need for oral hygiene programmes to be established.

An assessment of approximal bone height in the posterior segments of 15-16-year-old children using bitewing radiographs.

The alveolar bone height in a total of 713 15-16-year-old children consisting of 364 males and 349 females was assessed using posterior bitewing radiographs. The distance between the alveolar crest (AC) and amelo-cemental junction (ACJ) on all molar and premolar teeth was determined from magnified images of the radiographs. Analyses of variance models were fitted in order to assess the dependence of the overall ACJ to AC distance on the inter-subject variables of gender and social class and the intrasubject variables of site, missing adjacent tooth, condition of the approximal tooth surface, and for mesial surfaces, gingivitis and pocket depth. The overall geometric mean for bone height for the whole population was 0.542 mm. The ACJ to AC distance for the vast majority of sites was below 2 mm. Site had a highly significant effect on bone height (P < 0.001): ACJ to AC distances were greater in the maxilla compared to the mandible (P < 0.001), greater for distal sites compared to mesial (P < 0.001) and significantly affected by tooth type (P < 0.001). Sites with missing adjacent teeth also had significantly increased distances (P < 0.001). The condition of the approximal tooth surface and the presence of pocketing or gingivitis did not have a significant association with bone height. The geometric mean AC to ACJ distance, adjusted for subject, site and social class was 0.577 mm for males and 0.506 mm for females (P < 0.001), but the main effect of social class was not significant.

Dentine hypersensitivity: its prevalence, aetiology and clinical management.

Dentine hypersensitivity can be a frustrating condition to treat. The most common form of treatment is use of a desensitizing dentifrice, but for many patients this may provide only partial pain relief and recurrence is common. Recent research has provided several important findings which may serve as a basis for refining the approach to dentine hypersensitivity management, and for improving the success of treatment. This paper reviews the research and outlines a management system which transfers readily to clinical practice.

Oral health in the terminally ill: a cross-sectional pilot survey.

This study of 20 hospice patients provided baseline information on oral and dental status in the terminally ill. For each patient, a questionnaire was completed, the mouth was examined, and an oral rinse and imprint cultures were collected to establish the prevalence and intra-oral density of yeasts, staphylococci and coliforms. Oral symptoms reported included disturbance of taste (26%), dysphagia (37%), soreness (42%), and dryness (58%). Of the 75% who wore dentures, 71% had difficulty with their prosthesis (es). A clinical diagnosis of oral candidiasis was made in 70% of subjects. The high prevalence of oral symptoms, denture problems, and candidiasis clearly affect the quality of remaining life in terminally ill patients.

Traumatic injury to maxillary incisor teeth in a group of South Wales school children.

This study examines, from photographic records, the prevalence of accidental damage to maxillary incisor teeth in a group of 968 11/12-year-old South Wales school-children; 15.3% showed evidence of trauma ranging from enamel fractures or discolouration to actual loss of a tooth. Boys (19.4%) showed a higher prevalence of trauma than girls (11%). Maxillary central incisors were the most at risk from trauma, with coronal fractures being the most commonly sustained injury. Those subjects who showed evidence of trauma had an statistically (p less than 0.001) but not clinically significantly greater overjet than did those who had none. The percentage of subjects suffering trauma increased significantly with increasing overjet, but lip incompetence did not affect the prevalence of accidental damage. Though statistically unsupported due to the small numbers involved in this cohort, it appeared that the rougher nature of boys activities and their more active participation in sports were of greater importance than the magnitude of their overjet in determining whether their teeth were at risk from trauma. In contrast, it was the magnitude of the overjet which was the dominant factor in girls. Despite the wide availability of relatively simple means of restoration and, in the majority of cases, regular dental examinations, only 14.8% of traumatised teeth had received treatment at this age.

The effect of toothbrushing frequency, toothbrushing hand, sex and social class on the incidence of plaque, gingivitis and pocketing in adolescents: a longitudinal cohort study.

Reported toothbrushing frequency and the effect of toothbrushing frequency, toothbrushing hand, sex and social class on the incidence of plaque and periodontal disease in a group of 720 adolescents examined at age 11-12 years and again at 15-16 years is presented. At 11-12 years, the mean toothbrushing frequency was 11.5 times per week. By age 15-16 years, it had risen to 13.3 times per week. Children from social class I were less likely to brush once per day or less and more likely to brush twice daily than those from social class V. At both examinations, consistently low negative correlations were seen between reported toothbrushing frequency and the mean scores for buccal and lingual plaque, buccal, mesial and total bleeding. Few significant differences were seen between left- and right-handed toothbrushers at age 11-12 years. These were almost entirely due to differences between the boys. By age 15-16 years, no significant differences existed between the two groups. At both examinations, the boys had higher plaque, bleeding and pocketing scores than did the girls. At 15-16 years of age, all social classes exhibited lower mean total pocketing scores than at age 11-12 years. At 11-12 years of age, the social class differences were mainly contributed by the girls, while at re-examination plaque and bleeding scores for both sexes showed an overall trend to increase from social class I through to social class V. At 11-12 years of age, the boys showed a trend for pocketing to increase from social class I through to social class V. This was absent at 15-16 years of age. The girls showed no such trend at 11-12, but it had emerged by age 15-16. The results again demonstrate the influence of social class and sex rather than toothbrushing frequency and handedness on oral hygiene and gingival health. However, in view of the high number of statistical tests employed, some caution must be exercised in the interpretation of differences significant at the 5 per cent level.