Early Introduction of Sugar-Sweetened Beverages and Caries Trajectories from Age 12 to 48 Months.

Early exposure to sweet tastes predicts similar food preferences and eating behavior in later life and is associated with childhood obesity. The aim of this study was to explore the associations of early (during the first year of life) and subsequent intake of sugar-sweetened beverages (SSBs) with 4-y caries trajectories among Scottish young children. We used data from 1,111 Scottish children who were followed annually from age 12 to 48 mo (4 sweeps in total). SSB intake was reported by parents in every sweep. SSB intake was broken down into 2 components, the initial SSB intake and the deviation over time from that initial value. Childhood dental caries was clinically determined (including noncavitated and cavitated lesions) every year. The association of SSB intake with baseline decayed, missing, and filled tooth surfaces (dmfs) (intercept) and rate of change in dmfs over time (slope) was examined in 2-level linear mixed-effects models, with repeated observations nested within children. Both the initial SSB intake and the deviation from the initial SSB intake were positively associated with steeper caries trajectories. By sweep 4, the predicted mean dmfs difference was 1.73 between children with low and high initial SSB intake (1 standard deviation below and above the mean) and 1.17 between children with low and high deviation from their initial SSB intake (1 SD below and above the mean). The findings of this prospective study among Scottish young children provide evidence that the introduction of SSBs during the first year of life can put children in a trajectory of high levels of dental caries. They support current recommendations to avoid sugars for very young children and interventions targeting early feeding practices for caries prevention.

Birth Weight, Breastfeeding, Maternal Smoking and Caries Trajectories.

Evidence for the effects of low birth weight, breastfeeding and maternal smoking on childhood caries is mainly cross-sectional. We examined the association of these 3 putative early life factors with caries increment over a 4-y period among young children. We used data from a 4-y longitudinal caries-risk assessment study carried out among Scottish children. Early life factors were measured when children were aged 1 y (baseline). Caries assessment was repeated annually from ages 1 to 4, and the number of decayed, missing and filled primary tooth surfaces (dmfs) were used as a repeated outcome measure. The associations of low birth weight, breastfeeding and maternal smoking with dmfs at baseline and over time (trajectories) were assessed in linear mixed models. A total of 1,102 children were included in this analysis. Birth weight, breastfeeding and maternal smoking were not associated with dmfs at baseline. However, low birth weight and maternal smoking were associated with the rate of change in dmfs. By wave 4, the predicted mean difference in dmfs was 1.86 between children with low and normal birth weight, and 1.66 between children of smoking and non-smoking mothers. Children with low birth weight and smoking mothers had greater caries increments than those with normal weight and non-smoking mothers, respectively. There was no association between breastfeeding duration and childhood caries, either at baseline or over time.

Novel lesion detection aids.

Several non-invasive and novel aids for the detection of (and in some cases monitoring of) caries lesions have been introduced in the field of 'caries diagnostics' over the last 15 years. This chapter focusses on those available to dentists at the time of writing; continuing research is bound to lead to further developments in the coming years. Laser fluorescence is based on measurements of back-scattered fluorescence of a 655-nm light source. It enhances occlusal and (potentially) approximal lesion detection and enables semi-quantitative caries monitoring. Systematic reviews have identified false-positive results as a limitation. Quantitative light-induced fluorescence is another sensitive method to quantitatively detect and measure mineral loss both in enamel and some dentine lesions; again, the trade-offs with lower specificity when compared with clinical visual detection must be considered. Subtraction radiography is based on the principle of digitally superimposing two radiographs with exactly the same projection geometry. This method is applicable for approximal surfaces and occlusal caries involving dentine but is not yet widely available. Electrical caries measurements gather either site-specific or surface-specific information of teeth and tooth structure. Fixed-frequency devices perform best for occlusal dentine caries but the method has also shown promise for lesions in enamel and other tooth surfaces with multi-frequency approaches. All methods require further research and further validation in well-designed clinical trials. In the future, they could have useful applications in clinical practice as part of a personalized, comprehensive caries management system.

Traditional preventive treatment options.

Preventive treatment options can be divided into primary, secondary and tertiary prevention techniques, which can involve patient- or professionally applied methods. These include: oral hygiene (instruction), pit and fissure sealants ('temporary' or 'permanent'), fluoride applications (patient- or professionally applied), dietary assessment and advice (modification), other measures to help remineralize demineralized tissue and other measures to help modify the biofilm to reduce the cariogenic challenge. There is a considerable body of strong evidence supporting the use of specific techniques for primary prevention of caries in children, e.g. pit and fissure sealants and topically applied fluorides (including patient-applied fluoride toothpastes and professionally applied fluoride varnishes), but limited strong evidence for these techniques for secondary prevention--i.e. where early to established lesions with ICDAS codes 1-4 (and also the severer lesions coded 5 or 6) are involved--and in relation to adults. This lack of evidence reflects a shortage of high-quality trials in the area, as opposed to a series of good studies showing no effect. Since there is also limited longitudinal evidence supporting conventional operative care, and since controlling the caries process prior to first restoration is the key to breaking the repair cycle and improving care for patients, future research should address the shortcomings in the current level of supporting evidence for the various traditional preventive treatment options.

Novel preventive treatment options.

A number of novel preventive treatment options which, as with traditional methods, can be differentiated into 3 categories of prevention (primary, secondary and tertiary), have been and are being currently investigated. Those reviewed are either commercially available or appear relatively close to that point. These include: approximal sealants; fluoride applications, including slow-release devices; measures to help remineralize demineralized tissue, including 3 different methods of delivering amorphous calcium phosphate; measures to help modify the biofilm to reduce the cariogenic challenge, including ozone therapy and probiotics; measures to increase enamel resistance to demineralization, including laser treatment of enamel, and a novel 'hybrid' technique for the treatment of primary molar caries which involves 'overlapping' of secondary and tertiary prevention--the Hall technique. Although many of these techniques show considerable promise and dentists should be aware of these developments and follow their progress, the evidence for each of these novel preventive treatment options is currently insufficient to make widespread recommendations. Changes in dental practice should be explored to see how oral health can be best supported through novel preventive systems. Further research is also required involving double-blind randomized controlled trials in order to bring further benefits of more effective caries control to patients. Implementation in practice should follow promptly as new techniques are shown to be clinically valuable for individual patients.

Investigation of dental samples using a 35MHz focussed ultrasound piezocomposite transducer.

Dental erosion and decay are increasingly prevalent but as yet there is no quantitative monitoring tool. Such a tool would allow earlier diagnosis and treatment and ultimately the prevention of more serious disease and pain. Despite ultrasound having been demonstrated as a method of probing the internal structures of teeth more than 40 years ago, development of a clinical tool has been slow. The aim of the study reported here was to investigate the use of a novel high frequency ultrasound transducer and validate it using a known dental technique. A tooth extracted for clinical reasons was sectioned to provide a sample that contained an enamel and dentine layer such that the enamel-dentine junction (EDJ) was of a varying depth. The sample was then submerged in water and a B-scan recorded using a custom-designed piezocomposite ultrasound transducer with a centre frequency of 35 MHz and a -6 dB bandwidth of 24 MHz. The transducer has an axial resolution of 180 microm and a spatial resolution of 110 microm, a significant advance on previous work using lower frequencies. The depth of the EDJ was measured from the resulting data set and compared to measurements from the sequential grinding and imaging (SGI) method. The B-scan showed that the EDJ was of varying depth. Subsequently, the EDJ measurements were found to have a correlation of 0.89 (p<0.01) against the SGI measurements. The results indicate that high frequency ultrasound is capable of measuring enamel thickness to an accuracy of within 10% of the total enamel thickness, whereas currently there is no clinical tool available to measure enamel thickness.

Application of laser spectroscopy for measurement of exhaled ethane in patients with lung cancer.

There is increasing interest in ethane (C(2)H(6)) in exhaled breath as a non-invasive marker of oxidative stress (OS) and thereby a potential indicator of disease. However, the lack of real-time measurement techniques has limited progress in the field. Here we report on a novel Tunable Diode Laser Spectrometer (TDLS) applied to the analysis of exhaled ethane in patients with lung cancer. The patient group (n=52) comprised randomly selected patients presenting at a respiratory clinic. Of these, a sub-group (n=12) was subsequently diagnosed with lung cancer. An age-matched group (n=12) corresponding to the lung cancer group was taken from a larger control group of healthy adults (n=58). The concentration of ethane in a single exhaled breath sample collected from all subjects was later measured using the TDLS. This technique is capable of real-time analysis of samples with accuracy 0.1 parts per billion (ppb), over 10 times less than typical ambient levels in the northern hemisphere. After correcting for ambient background, ethane in the control group (26% smokers) ranged from 0 to 10.54 ppb (median of 1.9 ppb) while ethane in the lung cancer patients (42% smokers) ranged from 0 to 7.6 ppb (median of 0.7 ppb). Ethane among the non-lung cancer patients presenting for investigation of respiratory disease ranged from 0 to 25 ppb (median 1.45 ppb). We conclude that, while the TDLS proved effective for accurate and rapid sample analysis, there was no significant difference in exhaled ethane among any of the subject groups. Comments are made on the suitability of the technique for monitoring applications.

Influence of professional cleaning and drying of occlusal surfaces on laser fluorescence in vivo.

Three dentists recorded laser fluorescence (LF) values on 117 teeth in 70 patients, in the sequence: (1) moist, uncleaned; (2) dried, uncleaned; (3) moist, cleaned; (4) dried, cleaned. LF values varied significantly with surface status (p < 0.01). The optimal cutoffs were up to 5 units lower on uncleaned, moist surfaces compared to the other states. Drying uncleaned surfaces significantly increased LF readings for dentinal caries (p < 0.01). It was concluded that occlusal surfaces should be clean and dry, for precise longitudinal monitoring of caries with LF as well as for detailed visual inspection, which should precede LF measurements.

Visual and tactile assessment of arrested initial enamel carious lesions: an in vivo pilot study.

Accurate and reliable assessment of caries activity is important for determining appropriate treatment needs. The aim of this pilot study was to determine whether dentists could differentiate between the appearances (visual and tactile) of lesions inactivated by regular professional oral hygiene and those control lesions which were not cleaned (active). After a 3- to 4-week study period involving 10 children, with 4 similar carious lesions each, it was found that dentists were not able to reliably and reproducibly determine the subtle visual and tactile differences between active and inactive enamel lesions from a one-off clinical examination.

Tooth-brushing practices of parents and toddlers: a study of home-based videotaped sessions.

The aim of this pilot study was to investigate the tooth-brushing behaviour of parents and toddlers, by analysis of tooth-brushing sessions videotaped in families' homes. Eighteen families (self-selected from an ongoing preventive-intervention study) videotaped all home tooth-brushing sessions involving their toddler (average age 2.5 years) over a 24-hour period. The vast majority of families (89%) engaged in at least two sessions per day, usually supervised by mothers. The average length of the sessions was 142 s, although the brush tended to be in the child's mouth for less than half of that time. On average, only 10 s were spent brushing the front teeth, 13 s the back teeth, and 29 s spent on non-brushing activities (e.g., biting brush, sucking water). Three styles of brushing were identified, and families tended to be consistent in their use of these styles: exclusively parent-led (least common), exclusively child-led, and shared between parent and child (most common). In contrast with these poor behavioural outcomes, feedback from parents indicated that they were generally confident that the sessions had been effective in achieving clean teeth. These findings suggest that home-based tooth-brushing activity falls far short of professional expectations. Tooth-brushing, even with fluoride toothpaste, may be seriously compromised as a method of reducing caries in toddlers because teeth are being brushed too briefly.

The challenges of validating diagnostic methods and selecting appropriate gold standards.

Caries diagnostic methods are usually methods for caries lesion detection and measurement. Caries lesions occur on a continuous scale of tissue damage, from subclinical surface changes to macroscopic cavities reaching the pulp. Any change of a lesion on this continuous scale offers the opportunity for the diagnosis of disease activity or remission. Research aimed at remineralizing agents may focus on lesions that are amenable to remineralization, and select a method that will measure small changes in early lesions. General caries management strategies depend on detecting all stages of lesion development, and methods covering early to late stages are preferred. This paper addresses some methodological issues in validating caries diagnostic methods. The available gold standards for caries lesions are discussed, with their suitability in different applications, and their "validity" as far as it is known or can be inferred. The gold standards are compared as far as their measurement of lesion parameters and reproducibility is concerned. Tentative conclusions are formulated, and recommendations for future research are given.

Electrical measurements for use in caries clinical trials.

This paper reviews the use of electrical measurements of caries, particularly in relation to caries clinical trials. Electrical measurements change as tooth tissue porosity alters in the caries process, but several other variables also have a significant effect on these electrical measurements and hence upon their diagnostic validity. Available electrical-method data, in the context of clinical trials, relate to the use of the Electronic Caries Monitor (ECM), which measures "bulk" resistance. The device is presently limited in scope to occlusal surfaces, and only limited ECM data from clinical trials are available. In the context of clinical trials, more work is needed to determine the potential role of electrical measurements. Such research will need to focus both on an understanding of those electrical parameters which are most valuable in identifying changes and stages in the caries process in individual teeth and also on identifying the extent of the effects of the variables affecting these measurements.

Relationships between a clinical-visual scoring system and two histological techniques: a laboratory study on occlusal and approximal carious lesions.

One aim of the present laboratory study was to determine whether a visual scoring system (ERK) developed for occlusal caries could be applied to approximal lesions. A new histological technique (autofluorescence, AF) recognises dentine that is soft and would be removed with an excavator during operative treatment. A second aim was to investigate the relationship between the visual scoring system (ERK) and AF of dentine both occlusally and approximally. The sample comprised 93 extracted teeth chosen to represent the range of visual scores on approximal and occlusal surfaces. After sectioning through the investigation site, the cut faces were examined in a stereomicroscope and the depth of demineralization was scored. Autofluorescence was viewed with a confocal laser scanning microscope. Results showed reasonable correlation between the visual scores and the stereomicroscope histological evaluations for occlusal surfaces and non-cavitated approximal surfaces. However, cavitated approximal surface lesions were less advanced histologically than cavitated occlusal carious lesions. The AF technique indicated that several lesions with intact surfaces would have had soft, excavatable dentine, whereas several with microcavities would not.

Does social deprivation in 1, 2, 3 and 4-year-old Scottish infants influence the frequency isolation of caries-associated micro-organisms?

OBJECTIVES: The aim of this study was to determine if there are associations between the level of social deprivation/affluence and the frequency isolation of caries-associated micro-organisms (Streptococcus mutans, Streptococcus sobrinus, lactobacilli and yeasts) in a large cohort of infants examined annually from 1 to 4 years of age. METHODS: DEPCAT was used to measure the socio-economic status of all consented infants (n=1099--1392) born in Dundee during a 1 year period (total n=1974). Caries-associated micro-organisms were cultured from saliva when the infants were 1, 2, 3 and 4 years of age. Standardised dental examinations were also carried out annually. Log linear analysis, which controlled for caries, was used to look for associations between DEPCAT and the isolation frequency of caries-associated micro-organisms. RESULTS: When controlling for caries, there was an association between DEPCAT and the isolation frequency of yeasts when the infants were 1 and 2 but not when 3 and 4 years old, whereas lactobacilli were associated only when the infants were 3 and 4 years old. Correlations between S. mutans and social deprivation were usually dependent on the caries status of the infants. CONCLUSIONS: The relationship between social deprivation and the isolation frequencies of caries-associated micro-organisms is complex with lactobacilli developing an association when the infants were 3 and 4 years old in contrast to yeasts which were only associated when the infants were 1 and 2 years old. Streptococcus mutans was associated with social deprivation when the infants were 2 years old and older, but dependent on caries status in the 3 and 4 year olds.

Clinical performance of a laser fluorescence device for detection of occlusal caries lesions.

Children and adolescents must be examined often for occlusal caries. Diagnosis of fissure caries is difficult especially when the tooth surface appears seemingly intact. It has been shown that using traditional clinical methods, as little as 20% of teeth with fissure caries under intact surfaces were correctly recognised as such. Therefore, new methods for increasing the accuracy of diagnosis have been sought for years. Recently, a new device, based on fluorescence measurements, was introduced. The purpose of this study was to test the device under in vivo conditions in order to provide recommendations for its use in the dental office. Seven general dental practitioners examined a total of 332 occlusal surfaces in 240 patients. Caries extent was determined for each site after operative intervention (='gold standard'). Clinical inspection and analysis of bitewing radiographs exhibited statistically significant lower sensitivities (31-63%) than did the DIAGNOdent device (sensitivity > or = 92%). It is recommended that the laser device is used in the decision-making process in relation to the diagnosis of occlusal caries as a second opinion in cases of doubt after visual inspection.

A clinical evaluation of an Erbium:YAG laser for dental cavity preparation.

OBJECTIVE: A randomised controlled trial to determine the acceptability to dentists and patients of cavity preparation with an Erbium:YAG laser as compared with conventional handpieces. METHODS: Fifteen dentists (9 GDPs, 1 community dentist and 5 hospital dentists) treated 77 patients (age range 3.5-68 years old) who had two matched cavities, in a split mouth, randomised trial. One cavity was prepared conventionally, the other with the laser, with dentist and patient preference determined by questionnaire. RESULTS: In the majority of cases, where dentists expressed a preference, it was for conventional cavity preparation, and this was significant (P < 0.001). In more than half of the laser appointments, dentists had to use conventional handpieces to complete the cavity. Principle difficulties reported with the laser were access (25 cases) and slow speed of cutting (11 cases). Patients aged > or = 10 years who expressed a preference, preferred laser treatment, and this was significant (P < 0.001). Patients aged < 10 years, assessed using a simplified pictorial questionnaire, did not show a significant preference for either technique. CONCLUSIONS: Dentists preferred conventional handpieces for cavity preparation while patients aged > or = 10 years old preferred laser treatment. Patients < 10 years old did not express a preference.

Temperature dependence of the electrical resistance of sound and carious teeth.

Temperature variations are expected to influence measurement error in electrical resistance of teeth. It was the aim of this study to determine the changes in electrical behavior of extracted human teeth due to temperature changes in the range of room temperature to intra-oral temperature. Nine extracted teeth were selected, and the occlusal or an approximal surface was chosen for measurement. Carious involvement of the surfaces ranged from sound to cavitated. Electrical impedance spectroscopy sweeps in a frequency range of about 100 kHz to 10 Hz were completed at selected temperatures between 22 degrees C and 40 degrees C. After fitting the data to equivalent circuits that yielded parameter values for components of the equivalent circuit, we calculated the dc bulk resistance (Rh). The temperature dependence of Rb of the surfaces with different carious involvement was very similar, and the mean drop of Rb from 20 to 35 degrees C was 45% (SD 2%). It was concluded that the electrical resistance of sound and carious tooth surfaces is inversely related to temperature.