Carious enamel fails to reach equilibrium in the 30 s time-period. Crown-dentin green broken-line warms quicker than root-dentin pink broken-line. The carious dentin mustard solid-line is the slowest of all tissues to rewarm and fails to reach equilibrium within the time-frame. The characteristic-time-to-relaxation for carious enamel is 5.
This is the only occassion where enamel has a slower characteristic-time-to-relaxation than dentin. All other values give enamel 4. The enamel has a lower value of thermal diffusivity, ranging from 1. Thermal diffusivity shows the crown-dentin 0.
The carious area of dentin has an increased value of 1. The thermal conductivity of carious enamel 0. All other values of thermal conductivity for enamel and dentin within the carious tooth-slice are lower than others' findings. Figure 4. The two thermal maps distinguish the mineralized tissues of enamel, dentin and the carious areas of both tissues using the thermal properties of characteristic-time-to-relaxation and heat-exchange during rewarming Figure 5.
Figure 5. Sample 1- Sound tooth-slice and Sample 2 - Carious tooth-slice. Initially, a photograph is shown, followed by an X-ray, then the characteristic-time-to-relaxation thermal map and, finally, the heat-exchange thermal map depicting enamel, dentin and carious areas of enamel and dentin. Infra-red thermal imaging is a technique which is yet to be maximized within the field-of-medicine and its subsidiary specialty - dentistry.
Published work for determining the thermal properties of tooth-tissue Panas et al.
Dental Pulp Defence and Repair Mechanisms in Dental Caries.
Tooth-slice thicknesses of 2. Lin et al. Simultaneous heat-application to the irregular occlusal surface would be unlikely, compared to the application of vertical heat to the flat surface of the samples within this study and Panas et al. The tooth-slices within this study were viewed directly—unlike Lin et al.
They were also heated directly—unlike Panas et al. Neither of these additional layers was considered in their final calculations. Despite these variations, a single-sample Lin et al. Multiple samples from different teeth have not previously been reported from this technique, nor have areas of demineralization or caries. All samples are from different donors with inherent anomalies in the tissue-types, as previously described. Investigation of a point location or a single line of a single tissue-sample with 3 rides in vegas stratosphere temperature-recording-method, e.
The larger the area-of-interest used for each tissue and the greater the sample-size, the more valid and reliable any inference from the findings. Within this study, two samples, one sound and one carious with a demineralized area, were investigated with multiple areas-of-interest for each tissue.
Enamel values of thermal diffusivity and conductivity fall within proximity of known-ranges for the sound tooth-slice but do differ slightly between the two sides examined. Greater variation is seen within the demineralized enamel, where the carious area-of-interest returns the lowest values. This could be explained by the loss of mineral, but caution is needed as the range of values for the sound areas-of-interest differ by a similar proportion within the same sample.
These findings appear appropriate to the nature of the tissues being investigated and a more general outcome as described by Panas et al. That is, following the application of heat and analysis with thermal imaging, a difference between the thermal response of enamel and dentin was detectable, with enamel tending to conduct heat quicker than dentin. The data from this study agrees with that baseline principle and within the two samples presented - sound and demineralized - the thermal properties indicate that enamel conducts heat quicker than dentin within each sample.
Two exceptions are seen - one for carious enamel and one for the root-dentin outlier. The carious lesion will have a reduced mineral content - not quantified in this study - and returns a thermal conductivity which lies between the crown-dentin and carious dentin of the same tooth-slice. Comparison between sample-values does not agree with this principle and may be due to the natural variation of the samples from different people, the age of the teeth, the orientation of enamel prisms and dentinal tubules or the carious process.
Further work is needed to investigate these relationships. The purpose of this study was to see if enamel and dentin could be visualized from their individual thermal properties within a map. A thermal map provides a 2-dimensional diagram of the spatial relationship of every thermal value per pixel calculated across the whole tooth-slice. This advances the techniques previously described and adds to the information of an optical image. The thermal maps are produced from the gradient of the rewarming curve - characteristic-time-to-relaxation - and the integral of the curve - heat-exchange.
As seen in Figure 5the two types of thermal map do characterize enamel and dentin. The characteristic-time-to-relaxation map of sample one, the sound tooth-slice, shows a diffuse boundary between enamel and dentin and is sensitive to the tissue-thickness, as shown from the sloping-sides of the tooth-slice in the root-area.
This is radiolucent on the X-ray. The heat-exchange thermal map shows distinct contrast between enamel and dentin and the carious change within the enamel and dentin is clearly visible, compared to the characteristic-time-to-relaxation thermal map, where there is less contrast of the carious lesion within enamel and diffuse change is seen in dentin.
All the advantages of the characteristic-time-to-relaxation thermal map are retained by the heat-exchange thermal map. The spatial resolution defines the ability to distinguish two separate points but this does not necessarily transfer to diagnostic ability for the human operator.
The lesion shown within the demineralized tooth-slice is large, and the minimum size and level of demineralization detectable with this system is currently unknown and requires additional work with suitable test-objects.
Caries close to pulp
Spatial resolution can be limited due to equipment and the infra-red wavelength nm to 1 mm which will always be less than that of X-rays 0. This study has viewed slices of teeth in-vitronot a whole tooth, and the findings can underpin future models on whole teeth. Two studies have investigated carious lesions in whole human teeth in-vitro - one looking at artificially-created lesions on the smooth labial surface of incisors Kaneko et al.
The theory of a thermal difference between sound tooth-tissue and carious tissue was based on evaporative cooling due to an increase in moisture-content within the micro-pores of the carious lesion. This was found to provide a positive outcome in both studies.
Consideration of the thermal properties of the tissues, as seen in this study, were not presented in either of the whole-tooth studies, but their outcomes positively reinforce the need for further work.
This is being investigated for comfort and time-of-application. The use of thermal imaging to detect approximal caries is unlikely botox and medications it cannot penetrate tissues in the way X-rays do. However, detection of early smooth-surface lesions and occlusal lesions would allow preventive measures to be prescribed. X-rays have limitations, as previously mentioned, as do optical detection methods.
Thermal imaging may complement our current armamentarium. Detection of active and arrested caries remains uninvestigated with thermal imaging and consideration will be needed for other potential causes of difference in tooth structure and composition, e. The enamel and dentin of tooth-slices can be characterized in-vitro from their thermal properties, as seen in the thermal maps of heat-exchange and characteristic-time-to-relaxation. The heat-exchange map produces better contrast between enamel and dentin than the characteristic-time-to-relaxation map.
Within enamel and dentin, demineralized tissue can be detected in both maps, with heat-exchange providing the greatest contrast within both tissues. These thermal maps support further investigation of thermal imaging to complement diagnosis of caries. PL, DB, designed the Study, undertook the acquisition, analysis and interpretation of data, wrote the first draft of the manuscript, provided contribution to revision and final approval of the manuscript and are accountable for the work presented.
FC, VC, were involved with conception of the design, revision and approval of the manuscript.
Caris closet multiway
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. Some data within this manuscript was presented at the Enamel 9 Conference, 30th October to 3rd November, and PL's attendance at the Conference was supported by an Early Career Research Award from Enamel 9, which was gratefully received. Bader, J. The evidence supporting alternative management strategies for early occlusal caries and suspected occlusal dentinal caries.
Based Dent. A systematic review of the performance of methods for identifying carious lesions. Public Health Dent. Braden, M. With the conquering Hungarians a new population arrived to the Carpathian Basin in the Xth century, which was anthropologically different from the previous Avarian VllPth c.
However, the series of KE belonging to the upper class has much lower values compared either to the data from the previous and forthcoming period, or to the caries frequency of SO originating from the same age. From the comparative data it can be deduced that the prevalence of dental diseases changes not only through ages but even within them like in the case of the compared Xth- century sampleswhich can be explained by social and cultural factors of lifestyle.
Acquaviva M. Paleoodontologic Study of Pre-agricultural and Agricultural Populations. Acta Biologica, A szegvar-oromdûlôï Bennike P. Akademisk Forlag, Copenhagen. Boros S. Medicína Kóny vkiadó, Budapest. Dutour O. Hommes fossiles du Sahara. Peuplements holocénes du Mali septentrional. Balassi Kiadó, Budapest, pp. Huse L. Szegvar-Oromdûlô Kocsis S.
Larsen C. In: Cohen M. Academic Press, Inc. Lukacs R. In: Iscan Y. Alan R. Liss, Inc. Maczel M. Marcsik A. Molnar S. Observations of dental diseases among prehistoric populations in Hungary. American Journal of Physical Anthropology, Pap I. Oral pathology and social stratification in the Hungarian Middle Ages. Annales historico-naturales Musei nationalis hungarici, Roberts C. The Archaeology of Disease. Szikossy I. Antropológia - Régészet - Tàrténelem.
The Epidemiology of Dental Caries in Hungary. Akadémiai Kiadó, Budapest. Medicína Konyvkiadó, Budapest. Van Beek G. Dental Morphology - An illustrated guide. Ce matériau ne doit pas prévenir la résorption de la racine de la dent primaire, pour permettre à la dent permanente de pousser. Les auteurs de la revue travaillant avec le groupe Cochrane sur la santé bucco-dentaire ont effectué cette revue d'essais contrôlés randomisés.
Les données probantes sont à jour à la date d'août Nous avons inclus 87 essais examinant le succès du traitement de la pulpe des dents de lait. Les essais ont été publiés entre et et ont fourni comparaisons de différentes options de traitement. Le traitement de la pulpe pour les caries étendues des dents primaires est généralement efficace. La proportion d'échecs thérapeutiques était faible.
Bon nombre des essais inclus n'ont pas montré d'échec résultant des deux traitements comparés. Après une pulpotomie, l'agrégat de trioxyde minéral MTA semble être le meilleur matériau en termes de biocompatibilité et d'efficacité à mettre en contact avec le nerf dentaire racinaire restant.
En ce qui concerne le coiffage pulpaire direct, le petit nombre d'études traitant de la même comparaison limite toute interprétation. Nous avons jugé que la qualité des données probantes suggérant la supériorité du MTA sur l'hydroxyde de calcium ou le formocrésol après une pulpotomie était modérée.
En ce qui concerne les autres comparaisons, la qualité des données est mauvaise voire médiocre, ce qui signifie que nous ne pouvons pas être certains des résultats. Cette mauvaise qualité est due à des lacunes dans les méthodes utilisées au sein des essais individuels, au petit nombre d'enfants inclus dans les essais et au suivi à court terme après le traitement. Les futurs essais visant à évaluer quels agents de guérison sont les meilleurs pour les trois traitements de la pulpe nécessiteront une très grande taille d'échantillon et devront assurer le suivi des participants pendant au moins un an.
Tout essai futur dans ce domaine exigerait un très grand échantillon et un suivi d'au moins un an. Les données probantes suggèrent que le MTA pourrait être le médicament le plus efficace pour guérir la pulpe radiculaire après la pulpotomie d'une dent de lait.
Comme le MTA est relativement coûteux, des recherches futures pourraient être entreprises pour confirmer si la Biodentine, un dérivé de la matrice amélaire, le traitement au laser ou l'Ankaferd Blood Stopper sont des deuxièmes options acceptables et si, lorsqu'aucun de ces traitements ne peut être utilisé, l'application d'hypochlorite de sodium est la solution la plus sûre.
Le formocrésol, bien qu'efficace, suscite des inquiétudes quant à sa toxicité. En ce qui concerne la pulpectomie, il n'existe pas de données probantes qu'un médicament ou une technique est supérieur à un autre, de sorte que le choix du médicament est laissé à la discrétion du clinicien. Des recherches pourraient être entreprises pour confirmer si la pâte ZOE est plus efficace que la Vitapex mais également évaluer d'autres alternatives. En ce qui concerne le coiffage pulpaire direct, le nombre limité d'études et la faible qualité des données probantes ont limité l'interprétation.