Does replacement of missing dental units with resin-retained bridges improve oral health-related quality of life?: A systematic review.

OBJECTIVES: To assess the current literature in regard to two research questions: METHODS: Systematic review following the Preferred Reporting Items for Systemic Reviews and Meta-Analysis statement (PRISMA) statement. DATA/SOURCES: MEDLINE via Ovid, Scopus, PsycINFO via Ovid, Cochrane Library, Web of Science and clinicaltrials.gov were searched (Jan 1980 to Nov 2018) using high-level MeSH terms for studies published in English, investigating OHRQoL, using valid indices. RISK OF BIAS (ROB): Determined using Cochrane RoB tool and ROBINS-I. EVIDENCE CERTAINTY: Grading of Recommendations, Assessment, Development and Evaluation (GRADE) Working Group tool. RESULTS: Study Selection: 280 articles were identified; 270 were excluded after abstract review, 7 after examining full text, leaving 3 articles (3 studies, 188 participants, 172 analysed) included in this review; one RCT and two observational studies. Synthesis of results: There was significant heterogeneity and no meta-analysis was possible. Description of effect: One pre-post study design found provision of 2-unit RRBs significantly reduced the total OHIP-49 score (effect size 0.67), compared with an untreated control. One case-control study found no differences in total OHIP-49 between individuals treated with RRB or implant-supported crown. Major complications related to a worse OHRQoL. DISCUSSION: Quality of evidence: The overall RoB assessments were one study "some concerns" and two studies "serious". The GRADE assessment was "moderate" for one comparison and "low" for two comparisons. CLINICAL SIGNIFICANCE: A 2-unit cantilever RRB to replace one missing tooth probably results in a large improvement in oral health-related quality of life. Clinicians should ensure that the correct investigations and design of prosthesis are prescribed to help reduce any failures that may impact on OHRQoL.

Socioeconomic Variation in the association between Malocclusion and Oral Health Related Quality of Life.

OBJECTIVES: Oral health related quality of life (OHRQoL) has been linked to malocclusion. We aimed (a) to investigate the association between malocclusion and OHRQoL among children, and (b) to examine whether this association varied by socioeconomic status. METHODS: Cross-sectional analysis of data for 4,217 children aged 12 & 15 years, who participated in the 2013 Children Dental Health Survey (CDHS); a nationally representative survey of children in England, Wales, and Northern Ireland. Malocclusion was determined using the modified Index of Orthodontic Treatment Need (IOTN). OHRQoL was measured using the Child Oral Impacts on Daily Performance (Child-OIDP). For socioeconomic status, we used the pupils' eligibility for free school meals (FSM) and Index of Multiple Deprivation (IMD). Adjusted marginal effects were estimated controlling for confounding variables. Separate analyses were carried out for the two age groups. RESULTS: Malocclusion was associated with 6% and 15% increases in the probability of reporting negative impact of OHRQoL for 12- and 15-year olds respectively, which was significant for 15-year olds (marginal effect=0.15, 95% CI=0.08-0.22). Malocclusion was associated with the prevalence of oral impacts for 12 year olds (marginal effect=0.1, 95% CI=0.02-0.17) and 15-year olds (marginal effect=0.2, 95% CI 95%=0.13-0.28) not eligible for FSM and for 15-year olds in the most (marginal effect=0.2, 95% CI=0.1-0.29) and least (marginal effect=0.26, 95% CI=0.13-0.4) deprived IMD quintiles. CONCLUSIONS: Malocclusion was associated with impacts on OHRQoL for 15-year olds. There was evidence of a relationship between SES, malocclusion and OHRQoL.

Structural Determinants and Children's Oral Health: A Cross-National Study.

Much research on children's oral health has focused on proximal determinants at the expense of distal (upstream) factors. Yet, such upstream factors-the so-called structural determinants of health-play a crucial role. Children's lives, and in turn their health, are shaped by politics, economic forces, and social and public policies. The aim of this study was to examine the relationship between children's clinical (number of decayed, missing, and filled teeth) and self-reported oral health (oral health-related quality of life) and 4 key structural determinants (governance, macroeconomic policy, public policy, and social policy) as outlined in the World Health Organization's Commission for Social Determinants of Health framework. Secondary data analyses were carried out using subnational epidemiological samples of 8- to 15-y-olds in 11 countries ( N = 6,648): Australia (372), New Zealand (three samples; 352, 202, 429), Brunei (423), Cambodia (423), Hong Kong (542), Malaysia (439), Thailand (261, 506), United Kingdom (88, 374), Germany (1498), Mexico (335), and Brazil (404). The results indicated that the type of political regime, amount of governance (e.g., rule of law, accountability), gross domestic product per capita, employment ratio, income inequality, type of welfare regime, human development index, government expenditure on health, and out-of-pocket (private) health expenditure by citizens were all associated with children's oral health. The structural determinants accounted for between 5% and 21% of the variance in children's oral health quality-of-life scores. These findings bring attention to the upstream or structural determinants as an understudied area but one that could reap huge rewards for public health dentistry research and the oral health inequalities policy agenda.

Psychometric assessment of the short-form Child Perceptions Questionnaire: an international collaborative study.

OBJECTIVE: To examine the factor structure and other psychometric characteristics of the most commonly used child oral-health-related quality-of-life (OHRQoL) measure (the 16-item short-form CPQ11-14 ) in a large number of children (N = 5804) from different settings and who had a range of caries experience and associated impacts. METHODS: Secondary data analyses used subnational epidemiological samples of 11- to 14-year-olds in Australia (N = 372), New Zealand (three samples: 352, 202, 429), Brunei (423), Cambodia (244), Hong Kong (542), Malaysia (439), Thailand (220, 325), England (88, 374), Germany (1055), Mexico (335) and Brazil (404). Confirmatory factor analysis (CFA) was used to examine the factor structure of the CPQ11-14 across the combined sample and within four regions (Australia/NZ, Asia, UK/Europe and Latin America). Item impact and internal reliability analysis were also conducted. RESULTS: Caries experience varied, with mean DMFT scores ranging from 0.5 in the Malaysian sample to 3.4 in one New Zealand sample. Even more variation was noted in the proportion reporting only fair or poor oral health; this was highest in the Cambodian and Mexican samples and lowest in the German sample and one New Zealand sample. One in 10 reported that their oral health had a marked impact on their life overall. The CFA across all samples revealed two factors with eigenvalues greater than 1. The first involved all items in the oral symptoms and functional limitations subscales; the second involved all emotional well-being and social well-being items. The first was designated the 'symptoms/function' subscale, and the second was designated the 'well-being' subscale. Cronbach's alpha scores were 0.72 and 0.84, respectively. The symptoms/function subscale contained more of the items with greater impact, with the item 'Food stuck in between your teeth' having greatest impact; in the well-being subscale, the 'Felt shy or embarrassed' item had the greatest impact. Repeating the analyses by world region gave similar findings. CONCLUSION: The CPQ11-14 performed well cross-sectionally in the largest analysis of the scale in the literature to date, with robust and mostly consistent psychometric characteristics, albeit with two underlying factors (rather than the originally hypothesized four-factor structure). It appears to be a sound, robust measure which should be useful for research, practice and policy.

What is the value of orthodontic treatment?

Orthodontic treatment is as popular as ever. Orthodontists frequently have long lists of people wanting treatment and the cost to the NHS in England was £258m in 2010-2011 (approximately 10% of the NHS annual spend on dentistry). It is important that clinicians and healthcare commissioners constantly question the contribution of interventions towards improving the health of the population. In this article, the authors outline some of the evidence for and against the claims that people with a malocclusion are at a disadvantage compared with those without a malocclusion and that orthodontic treatment has significant health benefits. The authors would like to point out that this is not a comprehensive and systematic review of the entire scientific literature. Rather the evidence is presented in order to stimulate discussion and debate.

The effect of chewing gum on the impact, pain and breakages associated with fixed orthodontic appliances: a randomized clinical trial.

OBJECTIVES: To determine whether the use of chewing gum reduced the impact and pain of fixed orthodontic appliances. SETTING AND SAMPLE POPULATION: The Orthodontic Department of the Charles Clifford Dental Hospital, Sheffield, UK. Fifty-seven patients aged 18 years or younger and who were about to start fixed orthodontic appliance treatment. SUBJECTS AND METHODS: A randomized clinical trial with two parallel groups either allocated to receive chewing gum after placement of their appliance or who were asked not to chew gum. The patients completed a previously validated Impact of Fixed Appliances questionnaire at 24 h and 1 week following each visit up until the placement of the working archwire. A visual analogue scale (VAS) was used to assess the intensity of pain. Appliance breakages were recorded to the end of treatment. RESULTS: The difference between the median Total Impact Score of the two groups at 24 h was 16, which was significant (p = 0.031; Mann-Whitney U-test). The difference between the median VAS between the two groups at 24 h was 25 mm, which was significant (p = 0.038; Mann-Whitney U-test). There were no differences at 1 week. None of the risk ratios for appliance breakages were significant. CONCLUSION: Chewing gum significantly decreased both the impact and pain from the fixed appliances. There was no evidence that chewing gum increased the incidence of appliance breakages.

The cleaning of photographic retractors; a survey, clinical and laboratory study.

OBJECTIVES: To determine the methods currently being used to decontaminate photographic retractors in specialist orthodontic practice and to investigate the effectiveness of the cleaning methods. DESIGN: The study was carried out in two parts: I - a postal self-report questionnaire, and II - a cross-sectional clinical and laboratory investigation. SETTING: The Orthodontic Department of the Charles Clifford Dental Hospital. SUBJECTS AND MATERIALS: I - The questionnaire was sent to 278 specialist UK orthodontists. II - One hundred and twenty pairs of photographic retractors were collected following use. One retractor from each pair was randomly chosen to be the unwashed control and immediately placed in 20 ml of PBS-Tween for elution. The other was subjected to the one of four cleaning procedures: alcohol wipe, handwashing, ultrasonic bath or washer-disinfector, before being placed in PBS-Tween. Aliquots were taken for assay. MAIN OUTCOME MEASURES: Antibody capture (ELISA) for amylase, to detect the presence of saliva, and for albumin, to detect the presence of serum. RESULTS: I - The questionnaire response rate was 65% and the majority of respondents (87.2%) were routinely taking clinical photographs. A wide variety of techniques were being used to decontaminate photographic retractors. II - All unwashed controls had detectable levels of amylase and albumin. All the retractors that were cleaned using an alcohol wipe had residual detectable levels of amylase and 80% had detectable levels of albumin. Only one retractor had detectable amylase and one had detectable albumin following cleaning using the washer-disinfector. There was a highly significant statistical difference between the techniques in the proportional reduction in both amylase and albumin detected from the unwashed control and cleaned experimental retractors (p <0.001). The infective risk from inadequate cleaning of photographic retractors is discussed. CONCLUSIONS: The washer-disinfector is the most effective method of cleaning photographic retractors, but no method was found to be 100% successful at removing amylase and albumin.

Evaluation of a quality of life measure for children with malocclusion.

OBJECTIVE: To explore the validity and reliability of the child perception questionnaire as an oral-health-related quality of life (OHRQoL) measure in adolescents with malocclusion. DESIGN: A cross-sectional study comparing two groups of individuals. SETTING: One group of children with malocclusion was recruited from the orthodontic departments at the Charles Clifford Dental Hospital (CCDH), Sheffield and Chesterfield Royal Hospital (CRH), Chesterfield. A second group with no malocclusion was recruited from the Paediatric Department at CCDH and one General Dental Practice in Sheffield. SUBJECTS AND METHODS: The malocclusion group consisted of 116 patients aged 11-14 years about to commence orthodontic treatment. The non-malocclusion group consisted of 31 11-14-year-old patients with index of orthodontic treatment need (IOTN) 1 and 2, and DMFT

Reinforcement of anchorage during orthodontic brace treatment with implants or other surgical methods.

BACKGROUND: The term anchorage in orthodontic treatment refers to the control of unwanted tooth movement. This is conventionally provided either by anchor sites within the mouth, such as the teeth and the palate or from outside the mouth (headgear). Orthodontic implants which are surgically inserted to bone in the mouth are increasingly being used as an alternative form of anchorage reinforcement in orthodontics. OBJECTIVES: The primary objective of this review was to evaluate the effectiveness of surgical methods for preventing unwanted tooth movement compared with conventional anchorage reinforcement techniques. The secondary objectives were to examine patient acceptance, discomfort and failure rates associated with these techniques. SEARCH STRATEGY: The Cochrane Oral Health Group's Trials Register, CENTRAL, MEDLINE and EMBASE were searched. No language restrictions were applied. Authors were identified and contacted to identify unpublished trials. The most recent search was conducted in February 2006. SELECTION CRITERIA: Randomised or quasi-randomised clinical trials involving the use of surgically assisted means of anchorage reinforcement on orthodontic patients. Inclusion and exclusion criteria were applied when considering the studies to be included in this review. DATA COLLECTION AND ANALYSIS: Data extraction was performed by two review authors working independently using a previously piloted data collection form. Data were entered into RevMan with planned analysis of mean differences (MD) and 95% confidence intervals (CI) for continuous outcomes and risk ratios (RR) and 95% CI for dichotomous outcomes. Pooling of data and meta-analysis were not performed due to an insufficient number of similar studies. MAIN RESULTS: At present few trials have been carried out in this field and there are little data of adequate quality in the literature to meet the objectives of the review. The review authors were only able to find one study assessing the use of surgical anchorage reinforcement systems. This trial examined 51 patients with 'absolute anchorage' requirements treated in two centres. Patients were randomly allocated to receive either headgear or a mid-palatal osseointegrated implant. Anchorage loss was measured cephalometrically by mesial movement of dental and skeletal reference points between T1 (treatment start) and T2 (end of anchorage reinforcement). All skeletal and dental points moved mesially more in the headgear group than the implant group. Results showed significant differences for mesial movement of the maxillary molar in both groups. The mean change in the implant group was 1.5 mm (standard deviation (SD) 2.6; 95% CI 0.4 to 2.7) and for the headgear group 3.0 mm (SD 3.4; 95% CI 1.6 to 4.5). The trial was designed to test a clinically significant difference of 2 mm, so the result was not statistically significant, but the authors conclude that mid-palatal implants do effectively reinforce anchorage and are an acceptable alternative to headgear in absolute anchorage cases. AUTHORS' CONCLUSIONS: There is limited evidence that osseointegrated palatal implants are an acceptable means of reinforcing anchorage. The review authors were unable to identify trials addressing the secondary objectives of the review relating to patient acceptance, discomfort and failure rates. In view of the fact that this is a dynamic area of orthodontic practice we feel there is a need for high quality, randomised controlled trials. There are financial restrictions in running trials of this nature. However it would be in the interest of implant manufacturers to fund high quality, independently conducted, trials of their products.

Decontamination of orthodontic bands following size determination and cleaning.

OBJECTIVE: To measure the effectiveness of ultrasonic cleaning for decontaminating orthodontic molar bands following size determination using a quantitative antibody capture assay technique. DESIGN: A prospective, cross-sectional, clinical and laboratory investigation. SETTING: The Orthodontic Department of the Charles Clifford Dental Hospital and the Microbiology Laboratory of the School of Clinical Dentistry, Sheffield. PARTICIPANTS: Thirty-two patients about to start orthodontic treatment with fixed orthodontic appliances. METHODS: Four first molar bands were tried in the mouth and then removed. They were randomly assigned either for no decontamination (control) or to be decontaminated in an ultrasonic cleaning bath for 15 minutes (experimental). The bands were placed in a predetermined volume of phosphate-buffered saline (PBS) and assayed by enzyme-linked immunosorbent assay (ELISA) for albumin, to detect the presence of blood and amylase, to detect the presence of saliva. RESULTS: Fifty per cent of decontaminated molar bands showed detectable amounts of amylase, albumin or both. The quantity of detectable amylase was significantly reduced on the cleaned compared with uncleaned bands (P = 0.036); however, the reduction in the quantity of albumin was not statistically significant (P = 0.074). CONCLUSIONS: Ultrasonic cleaning for 15 minutes reduces, but does not always eliminate, salivary proteins (amylase) from tried-in bands. It is less effective at removing serum protein (albumin). There is a need, therefore, to investigate effective means of cleaning organic material from orthodontic bands if they are to be adequately sterilized and reused.

Molar band re-use and decontamination: a survey of specialists.

OBJECTIVE: To determine the pattern of use and re-use of orthodontic molar bands, and examine infection control measures in a sample of UK orthodontists. DESIGN: Questionnaire survey. SUBJECTS AND METHODS: Questionnaires were sent to 204 individuals selected at random from the UK Specialist Orthodontist list. Follow-up questionnaires were sent to those that had not replied within 8 weeks. An overall response rate of 74.5% was achieved. MAIN OUTCOME MEASURES: Orthodontic band use and re-use and cross-infection control. RESULTS: The reported rates of pre-sterilization cleaning and sterilization of orthodontic instruments were 92 and 100%, respectively. Of the respondents, 90% were using bands for molar teeth with the remainder routinely used bonded attachments. Most clinicians (95%) using bands routinely re-used them after being tried-in with 5% discarding them. Pre-sterilization cleaning of re-used molar bands was carried out by 92% of respondents who reclaimed bands. Sterilization of these bands was then carried out by most specialists apart from 2. CONCLUSIONS: The majority of UK specialist orthodontists who responded to the questionnaire are adhering to universal precautions for cross-infection control and are carrying out approved decontamination procedures. The majority are also reusing orthodontic bands that have been tried in the mouth, but found to be the wrong size. The great diversity of reported procedures for decontamination of instruments and bands suggest that more research is required to provide guidelines into the most effective method.

Fluorides, orthodontics and demineralization: a systematic review.

OBJECTIVES: To evaluate the effectiveness of fluoride in preventing white spot lesion (WSL) demineralization during orthodontic treatment and compare all modes of fluoride delivery. DATA SOURCES: The search strategy for the review was carried out according to the standard Cochrane systematic review methodology. The following databases were searched for RCTs or CCTs: Cochrane Clinical Trials Register, Cochrane Oral Health Group Specialized Trials Register, MEDLINE and EMBASE. Inclusion and exclusion criteria were applied when considering studies to be included. Authors of trials were contacted for further data. DATA SELECTION: The primary outcome of the review was the presence or absence of WSL by patient at the end of treatment. Secondary outcomes included any quantitative assessment of enamel mineral loss or lesion depth. DATA EXTRACTION: Six reviewers independently, in duplicate, extracted data, including an assessment of the methodological quality of each trial. DATA SYNTHESIS: Fifteen trials provided data for this review, although none fulfilled all the methodological quality assessment criteria. One study found that a daily NaF mouthrinse reduced the severity of demineralization surrounding an orthodontic appliance (lesion depth difference -70.0 microm; 95% CI -118.2 to -21.8 microm). One study found that use of a glass ionomer cement (GIC) for bracket bonding reduced the prevalence of WSL (Peto OR 0.35; 95% CI 0.15-0.84) compared with a composite resin. None of the studies fulfilled all of the methodological quality assessment criteria. CONCLUSIONS: There is some evidence that the use of a daily NaF mouthrinse or a GIC for bonding brackets might reduce the occurrence and severity of WSL during orthodontic treatment. More high quality, clinical research is required into the different modes of delivering fluoride to the orthodontic patient.

Differentiation of developmental and post-orthodontic white lesions using image analysis.

The aim of this study was to investigate differences in shape and size characteristics between developmental opacities and post-orthodontic white enamel lesions using computerized image analysis. Material, in the form of 35 mm slides, was obtained from the archive of photographic patient records in the orthodontic clinic at the Charles Clifford Dental Hospital. Images of 30 teeth with developmental white lesions and 30 teeth with post-orthodontic white lesions were selected using strict inclusion and exclusion criteria. The slides were converted to a digital format, coded, placed in a random order and analysed blindly using a computerized image analysis system by one clinician. After a 2 week interval, the images were recorded, placed in a new random order and the measurements repeated. The outcome measures were: area and luminance proportionality, and the shape of the perimeter line (expressed as the mathematical factor, roundness). Reproducibility was assessed by a paired samples t-test for systematic error and the intra-class correlation coefficient (ICC) for random error. Differences between groups were tested using the Mann-Whitney U-test for non-parametric data. Reproducibility was substantial for all measurements except for developmental white lesion roundness, which was moderate. There was a statistically significant difference between developmental white opacities and post-orthodontic white lesions for measurements of luminance intensity, proportionality (P = 0.002) and roundness (P = 0.001). Developmental white opacities had a higher luminance (i.e. were whiter) and the boundaries were more circular in shape than the post-orthodontic lesions. Roundness is a useful measure when distinguishing developmental and post-orthodontic demineralization.

Fluorides for the prevention of white spots on teeth during fixed brace treatment.

BACKGROUND: White spots can appear on teeth during fixed brace treatment because of early decay around the brace attachments. Fluoride is effective at reducing decay in susceptible individuals and is routinely prescribed in various different forms to patients during orthodontic treatment. OBJECTIVES: To evaluate the effectiveness of fluoride in preventing white spots during orthodontic treatment and to compare the different modes of delivery of fluoride. SEARCH STRATEGY: We searched the Cochrane Oral Health Group's Trials Register (to 22 August 2002); CENTRAL (The Cochrane Library Issue 3, 2002); MEDLINE (January 1966 to July 2003); EMBASE (January 1980 to week July 2003). Authors of trials were contacted for further data. SELECTION CRITERIA: Trials were selected if they met the following criteria: a randomised or quasi-randomised clinical trial, involving the use of a fluoride-containing product compared with no use or use of a non-fluoride control and enamel demineralisation was assessed during or after orthodontic treatment. DATA COLLECTION AND ANALYSIS: Six reviewers independently, in duplicate, extracted data. The primary outcome was the difference in the presence or absence of white spots between experimental and control patients for parallel design studies, and between experimental and control quadrants, for split-mouth design studies. Potential sources of heterogeneity were examined. Sensitivity analyses were undertaken for the items assessed for quality and publication bias. MAIN RESULTS: The primary outcome of the review was the presence or absence of white spots by patient at the end of treatment. Secondary outcomes included any quantitative assessment of enamel mineral loss or lesion depth. Other outcomes such as differences in size and severity of white spots, any patient based outcomes, such as perception of white spots could not be included because there were insufficient data. Fifteen trials, with 723 participants, provided data for this review. None of the studies fulfilled all of the methodological quality assessment criteria. There is some evidence that a daily sodium fluoride mouthrinse reduces the severity of enamel decay surrounding a fixed brace (weighted mean difference for lesion depth -70.0; 95% CI -118.2 to -21.8) and that use of a glass ionomer cement for bracket bonding reduces the prevalence (Peto OR 0.35; 95% CI 0.15 to 0.84) and severity of white spots (weighted mean difference for mineral loss -645 vol%.microm; 95% CI -915 to -375) compared with composite resins. REVIEWERS' CONCLUSIONS: There is some evidence that the use of topical fluoride or fluoride-containing bonding materials during orthodontic treatment reduces the occurrence and severity of white spot lesions, however there is little evidence as to which method or combination of methods to deliver the fluoride is the most effective. Based on current best practice in other areas of dentistry, for which there is evidence, we recommend that patients with fixed braces rinse daily with a 0.05% sodium fluoride mouthrinse. More high quality, clinical research is required into the different modes of delivering fluoride to the orthodontic patient.

Orthodontic palatal implants: clinical technique.

The aim of this paper is to familiarize the readers with some of the clinical considerations necessary to ensure successful use of mid-palatal implants. Both surgical and technical aspects will be discussed along with a description of impression techniques used.

Fluoridated elastomers: effect on disclosed plaque.

OBJECTIVE: To investigate the effect of fluoridated elastomers on the quantity of disclosed dental plaque surrounding an orthodontic bracket in vivo. DESIGN: A randomized, prospective, longitudinal clinical trial, employing a split mouth, crossover design. SETTING: The Orthodontic Departments of Liverpool and Sheffield Dental Hospitals. SUBJECTS AND METHODS: The subjects were 30 individuals about to start fixed orthodontic treatment. The study consisted of two experimental periods of 6 weeks with a washout period between. Fluoridated elastomers were randomly assigned at the first visit to be placed around brackets on 12, 11, 33 or 22, 21, 43. Non-fluoridated elastomers were placed on the contra-lateral teeth. After 6 weeks (visit 2) the elastomers were removed, the teeth disclosed and a photograph taken. Non-fluoridated elastomers were placed on all brackets for one visit to allow for a washout period. At visit 3, fluoridated elastomers were placed on the contra-lateral teeth to visit 1. At visit 4, the procedures at visit 2 were repeated. The photographs were scanned, then the area and proportion of the buccal surface covered with disclosed plaque was measured using computerized image analysis. A mixed-effects ANOVA was carried out with the dependent variable being the area or percentage area of disclosed plaque. RESULTS: There was no evidence of a systematic error and substantial agreement for the repeat readings of the same images. The only significant independent variable for the area of disclosed plaque was the subject (p < 0.001). The significant independent variables for the proportion of disclosed plaque were the subject (p < 0.001) and the tooth type (p = 0.002). The independent variable describing the use of fluoridated or non-fluoridated elastomers was not significant for either the area or the proportion of disclosed plaque. CONCLUSION: Fluoridated elastomers do not affect the quantity of disclosed plaque around an orthodontic bracket.

An in vitro assessment using transverse microradiography of the effect on mineral loss of etching enamel for in situ studies.

OBJECTIVES: To test the hypothesis that etching enamel with 37% phosphoric acid for 30 s does not lead to detectable mineral loss when measured with transverse microradiography (TMR). DESIGN: An in vitro laboratory investigation. EXPERIMENTAL VARIABLE: Forty bovine incisors were used in the experiment. The crowns of the teeth were covered with acid resistant varnish except for a rectangular area on the labial surface approximately 10 x 12 mm. On the exposed labial surface of 20 teeth an enamel lesion similar to that used in the in situ caries model was induced. Twenty teeth were left without a lesion. The exposed area was divided into three areas of equal size. The control area (C) was covered with acid resistant varnish throughout the experiment. The first experimental area (E1) was etched with 37% phosphoric acid for 30 s and a simulated bracket was bonded to the surface with composite resin. The second experimental area (E2) was left exposed for the remainder of the experiment. The teeth were placed in a demineralizing solution for 24, 48, 72 or 96 h to replicate different cariogenic challenges. OUTCOME MEASURE: Mineral loss as measured with TMR. RESULTS: There were no significant differences in the mineral loss between etched (E1) and etched (C) areas of enamel. There were significant differences in mineral loss between E1 and E2 for the 48 h (p < 0.001) and 72 h (p = 0.001) exposures without a pre-formed enamel lesion. CONCLUSION: There is no detectable mineral loss with TMR when enamel has been etched for 37% phosphoric acid for 30 s. The use of in situ enamel specimens with acid etch retained simulated brackets to investigate demineralization during orthodontics will not significantly affect the outcome compared with unetched specimens.

Does articulating study casts make a difference to treatment planning?

OBJECTIVE: To assess whether articulating casts in centric relation (CR) compared with intercuspal position (ICP) makes a difference to treatment planning. DESIGN: Reliability analysis. SUBJECTS: Ten orthodontists. METHODS: Twenty case vignettes were examined on three occasions: twice with the casts in ICP and once in CR. A series of dichotomous decisions were made relating to the treatment need and treatment mechanics. MAIN OUTCOME MEASURES: The changes in treatment decisions were examined. Intra-examiner agreement between the two hand-held cast assessments (H1 v. H2) and between the first set of hand-held casts compared with the articulated casts (H1 v. A1) were evaluated using the kappa statistic. The differences between the kappa statistics for H1 v. H2 and H1 v. A1 were then tested with the Wilcoxon matched pairs signed rank sum test. RESULTS: The only statistically significant change in the kappa score between H1 v. H2 and H1 v. A1 was for the extraction decision (P= 0.007). No other statistically significant differences were found for the other treatment decisions, although trends were identified for orthognathic surgery and anchorage support decisions. CONCLUSION: Routine articulation of study models for all orthodontic patients is not supported by the results of this study. Articulation of the study models did not affect the treatment planning decisions in a meaningful manner. Further work with selected samples is required to determine if articulation is helpful for specific malocclusions.

Enamel demineralisation assessed by computerised image analysis of clinical photographs.

OBJECTIVES: To investigate the use of computerised image analysis to measure the area of demineralisation on the buccal surface of a tooth and to analyse the effect on that measurement of varying the angle at which a photographic image of the buccal surface of a tooth is taken. METHODS: Twenty-two teeth with areas of incremental demineralisation on the buccal surface were photographed perpendicular to the buccal surface and at angles of 20 and 40 degrees, above (Cuspal) and below (Gingival) the perpendicular. The images were captured and analysed using computerised image analysis. RESULTS: The Gingival views showed lower limits of agreement than the Cuspal views, probably due to the positioning of the masking on the lower part of the flash, to reduce reflection. There was a significant difference between the areas of demineralisation measured for the three angles from the Gingival views (p<0.001). The mean differences in areas measured were not linear, but there was a significantly greater reduction in area measured for the 40 degrees views. CONCLUSIONS: Computerised image analysis to measure areas of demineralisation from a captured 35mm slide is reproducible. The position of the masking on the camera flash and the angle of the camera makes a difference to the area measured and the grey scales recorded. Images taken at a larger angle than 20 degrees to the perpendicular will record a significantly reduced area of demineralisation. Standardisation of photographs with the use of calibration markers and manipulation of images is discussed.

Reproducibility of quantitative measurement of white enamel demineralisation by image analysis.

The reproducibility of measuring artificial enamel white spot lesions from captured photographic images using computerised image analysis was assessed. Enamel lesions were induced on the buccal surface of 22 human teeth over periods of 3, 7 and 14 days. Standardised photographs were taken from above and below the occlusal plane. These were repeated after 2 weeks. The photographs were converted into TIFF images and mean grey scale levels of the areas of etched enamel were measured using computerised image analysis. Assessment of repeat readings of the same slide showed good reproducibility for photographs taken below the occlusal plane. The limits of agreement showed reasonable agreement between readings carried out on two slides of the same tooth. Capturing TIFF images via 35-mm film and measuring grey scale levels by computerised image analysis is a useful method of quantitative study of early enamel demineralisation. This may be developed for application in the clinical setting.