Dentin Topographic Features following Chemomechanical Caries Removal in Primary Teeth.

AIM: Study the topographic features of dentin after caries removal with a chemomechanical agent (Papacarie) compared with the conventional drilling method. STUDY DESIGN: The sample included 7 exfoliated and extracted primary teeth with carious dentin lesions, not reaching the pulp. Each tooth was sectioned longitudinally through the center of the carious lesions into two halves. The teeth were then divided into two groups according to the method of caries removal. Following caries removal, dentin topography and the cut section were examined using the scanning electron microscope. RESULTS: Papacarie produced an irregular, porous, rough and globular dentin appearance. The dentin surfaces were generally free of smear layer, visible bacteria and the dentinal tubules were opened. The dentin cut surfaces showed patent dentinal tubules with open orifices. The drilling method created a smooth and amorphous surface with a continuous smear layer occluding the dentinal tubules. Numerous bacteria were also observed. The cut dentin surfaces showed patent dentinal tubules with their orifices plugged with smear layer. CONCLUSIONS: Papacarie produced a rough and porous surface with partial or complete removal of the smear layer and opened dentinal tubules, while the drill produced a smooth surface with uniform smear layer occluding the dentinal tubules.

In Vitro Evaluation of Microleakage and Microhardness of Ethanolic Extracts of Propolis in Different Proportions Added to Glass Ionomer Cement.

OBJECTIVE: To evaluate the effect of ethanolic extracts of propolis (EEP) addition in different proportions to glass ionomer cement (GIC) on microleakage and microhardness of GIC. STUDY DESIGN: The cement was divided into four groups: one using the original composition and three with 10%, 25%, and 50% EEP added to the liquid and then manipulated. For microleakage assessment, sixty primary molars were randomly divided into four groups (n=15). Standard Class II cavities were prepared and then filled with EEP in different proportions added to GICs. Microleakage test was performed using a dye penetration method. The data were analyzed using one-way ANOVA and Mann-Whitney U tests (α = 0.05). Disc shaped specimens were prepared from the tested GIC to determine Vickers hardness (VHN). The data were analyzed using one-way ANOVA and post hoc Tukey test (α = 0.05). RESULTS: There were no statistically significant differences between the groups in terms of microleakage (p > 0.05). There were statistically significant differences between the VHN values of groups (p < 0.05). Increasing addition of EEP to GIC statistically significantly increased VHN value of GIC (p < 0.05). CONCLUSIONS: The addition of EEP to GIC increased the microhardness of the GIC and did not adversely affect the microleakage. Thus, it might be used during routine dental practice due to its antibacterial properties.

Clinical, mineral and ultrastructural changes in carious dentin of primary molars after restoration.

INTRODUCTION: Partial caries removal has been shown to be an effective method to treat deep carious lesions in deciduous teeth. Nevertheless, the possibility of keeping infected dentin in the cavity still requires additional investigation. The objective of this research was to describe changes in primary infected dentin after restoration with glass ionomer cement. METHODS: Dentin from 45 primary molars with deep and active carious lesions was evaluated using clinical and laboratory criteria, before and 60 days after restoration. The clinical analysis evaluated dentin colour (CO), dentin consistency (COS) and laser fluorescence (LF). The laboratory procedures assessed bacterial contamination and mineral content (MC), and evaluated the dentin ultrastructure and collagen content. Data on CO, COS, LF and colony forming units were analysed using the Wilcoxon signed-rank test; MC, bacterial counts and collagen evaluations were evaluated using the Student's t-test. RESULTS: After 60 days, lower values of LF were observed, together with a lower bacterial count, and a higher COS was found, with an increase in calcium, phosphorus and collagen contents. Differences were not detected for CO or for fluorine content. Baseline samples showed enlarged tubules with bacterial invasion; 60-day samples showed better organised tissue, with a more compact intertubular dentin and narrower tubules. CONCLUSION: It is concluded that appropriate cavity sealing can promote beneficial changes in deep carious lesions of primary teeth, even in the presence of infected dentin.

Evaluation of different irrigating solutions on smear layer removal of primary root dentin.

AIM: To evaluate the efficacy of ethanolic extract of Salvadora persica (S. persica) and BioPure MTAD (a mixture of a tetracycline isomer, an acid, and a detergent) in removing the intracanal smear layer of primary teeth. MATERIALS AND METHODS: The root canal of 40 extracted human primary anterior teeth were cleaned, shaped and grouped into experimental (n = 30) and control (n = 10). The root canals of the positive (n = 5) and the negative control (n = 5) were irrigated for 3 minutes with 5 ml of 17% ethylenediaminetetraacetic acid (EDTA) or saline respectively. The canals in the experimental groups were irrigated for 3 minutes with 5 ml of 1 mg/ml ethanolic extract of S. persica (n = 15) or BioPure MTAD (n = 15) and then flushed with 2 ml of saline. The presence or absence of smear layer at the coronal and middle portion of each canal were examined under a scanning electron microscope (SEM). RESULTS: A significant difference (p = 0.004) in smear layer removal between S. persica and MTAD at the middle third of the canal was observed. MTAD solution was as effective as 17% EDTA in removing the smear layer. CONCLUSION: MTAD was significantly more effective in smear layer removal than S. persica solution at the middle third of the canal wall. CLINICAL SIGNIFICANCE: Both tested irrigant solutions have the ability to remove the intracanal smear from primary root dentin following cleaning and shaping of the root canal and could be an alternative to EDTA.

A spectroscopic and surface microhardness study on enamel exposed to beverages supplemented with lower iron concentrations.

OBJECTIVES: This study aimed to compare the in vitro mineral loss and surface microhardness (SMH) changes in human enamel specimens following supplementation of acidic carbonated beverages with low iron concentrations than when treated without. STUDY DESIGN: 180 enamel blocks each from primary and permanent teeth were prepared and equally subdivided (n=10) for their respective treatments in Group 1 (Coca Cola and Sprite without iron supplementation) and Group 2 (beverages supplemented with 2/5 mmol/L FeSO4.7H2O). Following initial SMH estimation, the blocks were subjected to 3 treatment cycles of 5/20 minute incubation periods, equally interspaced by a 5-min treatment in artificial saliva. The calcium and phosphate released after each cycle were analyzed spectrophotometrically and the final SMH was recorded. The results were tested using student's T test, One-way ANOVA and Kruskal Walli's test (p<0.05). RESULTS: Two and five mmol/L FeSO4.7H2O supplementation produced a highly significant SMH change and calcium and phosphate reduction than when treated without (p<.0005). Both the enamel specimens showed similar patterns of mineral loss and SMH reduction, with pronounced effects in the twenty minute incubation cycles. CONCLUSION: Our results suggest that 2 mmol/L FeSO4.7H2O supplementation to acidic beverages is beneficial in reducing mineral loss and preserving surface microhardness of human enamel.

Morphological, chemical and structural characterisation of deciduous enamel: SEM, EDS, XRD, FTIR and XPS analysis.

AIM: The purpose of this study was to characterise the enamel surface of sound deciduous teeth in terms of morphology, chemical composition, structure and crystalline phases. MATERIALS AND METHODS: The enamel of 30 human deciduous teeth was examined by: Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Spectroscopy (EDS), X-ray Powder Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and X-ray Photoelectron Spectroscopy (XPS). Chemical differences between incisors and canines were statistically evaluated using the Mann-Whitney U test (p ≤ 0.05). RESULTS: Three enamel patterns were observed by SEM: 'mostly smooth with some groves', 'abundant microporosities' and 'exposed prisms'. The average Ca/P molar ratios were 1.37 and 1.03 by EDS and XPS, respectively. The crystallite size determined by XRD was 210.82 ± 16.78 Å. The mean ratio between Ca bonded to phosphate and Ca bonded to hydroxyl was approximately 10:1. CONCLUSION: The enamel of sound deciduous teeth showed two main patterns: 'mostly smooth with some groves' and 'abundant microporosities'. 'Exposed prisms' was a secondary pattern. There were slight variations among the Ca/P molar ratios found by EDS and XPS, suggesting differences in the mineral content from the enamel surface to the interior. The crystalline phases found in enamel were hydroxyapatite and carbonate apatite, with major type B than type A carbonate incorporation.

An ex vivo study of arrested primary teeth caries with silver diamine fluoride therapy.

OBJECTIVES: This ex vivo study compared the physico-chemical structural differences between primary carious teeth biannually treated with silver diamine fluoride (SDF) and carious teeth without such treatment. METHOD: Twelve carious primary upper-central incisors were collected from 6-year-old children. Six teeth had arrested caries after 24-month biannual SDF applications and 6 had active caries when there was no topical fluoride treatment. The mineral density, elemental contents, surface morphology, and crystal characteristics were assessed by micro-computed tomography (micro-CT), energy-dispersive X-ray spectrometry (EDX), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). RESULTS: Micro-CT examination revealed a superficial opaque band approximately 150µm on the arrested cavitated dentinal lesion. This band was limited in the active carious lesion. EDX examination detected a higher intensity of calcium and phosphate of 150µm in the surface zone than in the inner zone, but this zone was restricted in the active cavitated dentinal lesion. SEM examination indicated that the collagens were protected from being exposed in the arrested cavitated dentinal lesion, but were exposed in the active cavitated dentinal lesion. TEM examination suggested that remineralised hydroxyapatites were well aligned in the arrested cavitated dentinal lesion, while those in the active cavitated dentinal lesion indicated a random apatite arrangement. CONCLUSIONS: A highly remineralised zone rich in calcium and phosphate was found on the arrested cavitated dentinal lesion of primary teeth with an SDF application. The collagens were protected from being exposed in the arrested cavitated dentinal lesion. CLINICAL SIGNIFICANCE: Clinical SDF application positively influences dentine remineralisation.

Casein phosphopeptide-amorphous calcium phosphate remineralization of primary teeth early enamel lesions.

UNLABELLED: Early childhood caries (ECC) is a serious problem that progresses rapidly and often goes untreated. Current traumatic treatments may be replaced by safe and effective remineralization at very early stages. OBJECTIVE: The aim of this in vitro study was to evaluate the remineralization effects of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) paste on enamel lesions by assessing ultrastructure, nanomechanical properties, and compound and elemental analysis. METHODS: Enamel specimens from 6-year-old children were divided into groups: (1) native enamel; (2) water as negative control; (3) 500ppm NaF as positive control; and (4-7) CPP-ACP paste for 4, 8, 12, and 24h, as test groups. Ultrastructure and roughness were observed by atomic force microscopy (AFM); nanohardness and elastic modulus were measured by nanoindentation; compound and crystal size of enamel surface patterns were investigated by X-ray diffractometer (XRD). An electron microprobe (EPMA) was used for element analysis. Data were analyzed using one-way ANOVA. RESULTS: The CPP-ACP paste repaired the microstructure of enamel, including prism and interprism, through significantly increased hydroxyapatite crystal size (12.06±0.21nm) and Ca/P molar ratios (1.637±0.096) as compared with NaF (8.56±0.13nm crystal size and 1.397±0.086 Ca/P, p<0.01). Both CPP-ACP and NaF decrease roughness, and increase the nanohardness and elastic modulus, with no significant differences between the materials. CONCLUSIONS: The CPP-ACP paste is more suitable for children than NaF, due to advantages for remineralization. The AFM, nanoindentation, EPMA, and XRD are very helpful methods for further understanding of microscale and nanoscale remineralization mechanisms.

Resin bonding using etch-and-rinse and self-etch adhesives to decalcified deciduous enamel after bioactive glass air abrasion.

PURPOSE: Bioactive glass air abrasion is a conservative technique for removal of initial decalcified enamel superficial layer and caries vs alumina air abrasion. This study evaluated shear bond strength of composite resin to sound and decalcified deciduous enamel using etch-and-rinse and self-etch adhesives after alumina and bioactive glass air abrasion. MATERIALS AND METHODS: Ninety-six fat enamel surfaces, mounted in acrylic resin, were prepared from 48 deciduous molars. Half of the specimens were decalcified with a demineralizing solution. Both intact and decalcified specimens were assigned to two groups for alumina and bioactive glass air abrasion. In each group, the specimens were subdivided into two groups for application of Clearfil SE Bond or Optibond FL adhesives (n = 12). After composite resin bonding, the specimens underwent shear bond test. Data were analyzed using three-way analysis of variance (ANOVA), linear regression model and independent-sample t-test (α = 0.05). RESULTS: No significant differences were noted in bond strength of composite resin after alumina or bioactive glass air abrasion (p = 0.272). Optibond FL adhesive and enamel decalcification produced higher bond strength (p = 0.000, p = 0.001 respectively). CONCLUSION: In this study, bioactive glass air abrasion produced bond strength comparable to the conventional method. This technique might be an alternative method for preparation of normal and/or decalcified enamel of deciduous teeth for resin bonding.

Temperature changes in the pulpal chamber and the sealing performance of various methods of direct pulp capping of primary teeth.

AIM: To compare changes in pulpal chamber temperature during the visible-light curing of direct pulp capping compounds and various modes of diode laser irradiation without prior placement of a pulp capping compound and the resultant seals. MATERIALS AND METHODS: Pulp exposure holes were made in 100 extracted human primary first molars, which were randomly assigned to ten equal groups. The holes were sealed by (a= Group 1, 2, 3, 4, 5, 6 and 7) different pulp capping compounds which were cured using various types of visible-light curing units or (b=Group 8, 9 and 10) diode laser irradiation without prior application of a pulp capping compound. Pulpal chamber temperatures were recorded during the procedure, and the resultant seals were examined under a scanning electron microscope. RESULTS: Visible-light curing of the pulp capping compounds and diode laser irradiation at a 0.7 W output power can cause non-injurious temperature rises in the pulpal chamber. At higher output powers of the diode laser, the temperature rises are sufficient to cause thermal injury. The seals were complete when pulp capping compounds were used for direct pulp capping, but were incomplete when laser irradiation without prior placement of a pulp capping compound was used for the identical purpose. CONCLUSION: The visible-light curing of pulp capping compounds is not harmful to vital pulp, and provides an effective seal of the pulp exposure hole. Laser irradiation is not an effective sealant, and can cause thermal injury to vital pulp at high output powers.

Effect of ammonium hexafluorosilicate application for arresting caries treatment on demineralized primary tooth enamel.

Ammonium hexafluorosilicate (AHF) has been applied to arrest caries without discoloration. The purpose of this study was to observe structural and elemental changes of demineralized and AHF applied primary tooth enamel. Enamel from the labial surface of 20 primary canines was divided into an unground side and ground side at the center of the tooth, and demineralized with 35% phosphoric acid for 6 min. The teeth were divided into 4 groups according to a 3-min application of AHF and 1 week of soaking in artificial saliva, as follows: group A (neither AHF nor saliva), group B (only saliva), group C (only AHF), and group D (AHF and saliva), and then subdivided according to whether the enamel was ground or unground. Specimens were analyzed with scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDS). The data were statistically analyzed using ANOVA and Fisher's PLSD test at α = 0.05. In groups A and B, prism structures were seen, however, in groups C and D, enamel surfaces were covered with spherical particles. Ca/P ratio was significantly higher in groups C and D than in groups A and B. There was no significant difference between ground and unground enamel in the content of any element. The values for F, Na, Mg and Si persents and Ca/P ratio were significantly higher for the enamel surface than for points 10-30 µm beneath the surface. Results of this study suggest the possibility that AHF treatment arrests caries, although further study will be required to confirm this result.

The effect of the season of birth and of selected maternal factors on linear enamel thickness in modern human deciduous incisors.

OBJECTIVE: Development of human tooth enamel is a part of a foetus's development; its correctness is the outcome of genetic and maternal factors shaping its prenatal environment. Many authors reported that individuals born in different seasons experience different early developmental conditions during pregnancy. In this study, we investigated the effects of season of birth and selected maternal factors on enamel thickness of deciduous incisors. DESIGN: Dental sample comprises 60 deciduous incisors. The parents who handed over their children's teeth for research fill in questionnaires containing questions about the course of pregnancy. All teeth were sectioned in the labio-linqual plane using diamond blade (Buechler IsoMet 1000). The final specimens were observed by way of scanning electron microscopy at magnifications 80× and 320×. The thickness of total enamel (TE), prenatally (PE) and postnatally (PSE) formed enamel was measured. RESULTS: Children born in summer and in spring (whose first and second foetal life fall on autumn and winter) have the thinnest enamel. Season of birth, number of children in family, diseases and spasmolytic medicines using by mother during pregnancy explained almost 13% of the variability of TE. Regression analysis proved a significant influence of the season of birth and selected maternal factors on the PE thickness - these factors explained over 17% of its variability. Neither of analysed variables had influenced PSE. CONCLUSIONS: Our findings suggests that the thickness of enamel of deciduous incisors depends on the season of birth and some maternal factors. The differences were observed only in the prenatally formed enamel.

Microtensile bond strength of self-etch adhesives in different surface conditionings.

AIM: Self-etch bonding systems have been introduced recently and have the advantage of reduced operating time. Because of patient management and isolation difficulties in children, the present study aimed to evaluate microtensile bond strength of two self-etch bonding systems (AdheSE and Xeno® III) on cleaned only, ground and sandblasted enamel. MATERIALS AND METHODS: Thirty intact primary molars were selected and randomly divided into two groups according to the type of bonding used (Xeno® III and AdheSE). The teeth were divided into three subgroups according to enamel surface conditioning method: prophylaxis with pumice, grinding with coarse finishing and polishing disc, and sandblasting with aluminum oxide particles. Tetric Ceram composite then was applied. Samples were sectioned coronally and axially. The interface area of dental sticks was measured and specimens were subjected to a tensile force of 0.5 mm/min until failure. RESULTS: Microtensile bond strength of Xeno® III-sandblasting, AdheSE-sandblasting, AdheSE-grinding, and AdheSE- cleaned only were 25.5±7.7, 21.2±2.3, 12.9±2.2, and 9.1±1.1, respectively. During sectioning, all specimens of Xeno® III-cleaned only and Xeno® III-grinding groups were fractured. CONCLUSIONS: Two step AdheSE yields higher mTBS in comparison to one step Xeno ® III. In regard to surface conditioning, sandblasting increases the mTBS relative to grinding with finishing and polishing disc, and the cleaned-only enamel has the lowest mTBS.

Carisolv as an endodontic irrigant in deciduous teeth: an SEM study.

AIM: Root canal irrigation plays an important role in the debridement and disinfection of the root canal system. "The purpose of this study was to evaluate the efficacy of Carisolv , 1% sodium hypochlorite (NaOCl) gel, and 1% NaOCl solution as root canal irrigants in deciduous anterior teeth." MATERIALS AND METHODS: THIRTY-six extracted deciduous anterior teeth were used. Root canals were flooded with NaOCl solution in Group A, NaOCl gel in Group B and Carisolv in Group C and incubated for 30 min. Scanning electron microscope photomicrographs of canal wall debris in the apical, middle and coronal thirds were scored. RESULTS: The results showed that regardless of irrigation regime, canals were consistently cleaner in the coronal and middle thirds than in the apical thirds. NaOCl solution, NaOCl gel, and Carisolv had comparable activity at coronal third and middle third of root canals. At the apical third, NaOCl solution cleaned canals better than NaOCl gel and Carisolv. Carisolv cleaned debris better than NaOCl gel at the apical third. CONCLUSION: Carisolv can be used as an adjunct to root canal preparation.

Efficiency of different polyacrylic acid concentrations on the smear layer, after ART technique, by Scanning Electron Microscopy (SEM).

AIM: To assess the efficiency of different polyacrylic acid concentrations on the removal of the smear layer after caries removal with hand and rotary instruments in affected dentine of primary teeth. STUDY DESIGN: In vitro study. METHODS: Six exfoliated primary molars with carious lesions were divided into two groups for caries removal: (1) hand instrument or (2) low speed bur. Each tooth was cut into four pieces. One piece assigned as control surface and the other three surfaces were actively treated with either 40% Fuji IXGP Liquid (GC America), or 40% Fuji IXGP Liquid diluted with water, and 25% Ketac Molar(TM) Conditioner (3M-ESPE). Surfaces were prepared for scanning electron microscopy (SEM). All images were submitted to an analysis by an experienced SEM professional, regarding presence or absence of smear layer and dentinal demineralization pattern. Chi-squared test was carried out (5% significance). RESULTS: There was no difference concerning the presence of a smear layer in relation to the method of caries removal, and 40% Fuji IXGP diluted with water causes a higher demineralization when compared with the control group of teeth (p=0.01). CONCLUSION: Treatments with polyacrylic acid are indicated prior to glass ionomer cement application in primary teeth.

Altered inorganic composition of dental enamel and dentin in primary teeth from girls with Turner syndrome.

In Turner syndrome (TS) one X-chromosome is missing or defective. The amelogenin gene, located on the X-chromosome, plays a key role during the formation of dental enamel. The aim of this study was to find support for the hypothesis that impaired expression of the X-chromosome influences mineral incorporation during amelogenesis and, indirectly, during dentinogenesis. Primary tooth enamel and dentin from girls with TS were analysed and compared with the enamel and dentin of primary teeth from healthy girls. Qualitative and quantitative changes in the composition of TS enamel were found, in addition to morphological differences. Higher frequencies of subsurface lesions and rod-free zones were seen in TS enamel using polarized light microscopy. Similarly, scanning electron microscopy showed that the enamel rods from TS teeth were of atypical sizes and directions. Using X-ray microanalysis, high levels of calcium and phosphorus, and low levels of carbon, were found in both TS enamel and dentin. Using microradiography, a lower degree of mineralization was found in TS enamel. Rule induction analysis was performed to identify characteristic element patterns for TS. Low values of carbon were the most critical attributes for the outcome TS. The conclusion was that impaired expression of the X-chromosome has an impact on dental hard tissue formation.

Evaluation of the furcation area permeability of deciduous molars treated by neodymium:yttrium-aluminum-garnet laser or adhesive.

The purpose of this in vitro study was to compare the effects of a self-etch adhesive system and neodymium:yttrium-aluminum-garnet (Nd:YAG) laser application on the dentinal permeability of the furcation area of primary molars. After endodontic access, 39 extracted human deciduous molars were divided into three groups: control group (CG), no treatment; adhesive group (AG), self-etching adhesive was applied to the furcation area; laser group (LG), specimens were irradiated with Nd:YAG laser. To evaluate dentin permeability of the furcation area, we immersed the specimens in 0.5 % methylene blue dye for 4 h. Then, they were longitudinally sectioned into two halves and photographed. The images were analyzed by two qualified evaluators using TpsDig software to calculate the percentage of the dye penetration area in comparison with the total furcation area. Additional analyses by scanning electron microscopy (SEM) were performed. The analysis of variance (ANOVA), complemented by Student's t-test, showed that mean dye penetration in the LG was statistically significant lower than that in all the other groups (P < 0.05). The SEM analysis showed mostly dentinal tubules obliterated by smear layer in the CG; in the AG the smear layer was modified by the adhesive, and, in the LG, melted surfaces were observed. It can be concluded that the Nd:YAG laser was capable of reducing the dentinal permeability of the furcation area of deciduous molars.

Surface morphology of sound deciduous tooth enamel after application of a photo-absorbing cream and infrared low-level laser irradiation: an in vitro scanning electron microscopy study.

OBJECTIVES: The purpose of this descriptive scanning electron microscopic study was to characterize surface alterations in deciduous tooth enamel after in vitro infrared diode laser irradiation, using a photo-absorbing agent alone and also combined with fluoride, before and after laser irradiation. BACKGROUND DATA: Previous investigations have demonstrated increased enamel caries resistance after laser irradiation. METHODS: Seven extracted or exfoliated primary molar teeth underwent soft tissue débridement and fluoride-free prophylaxis. Buccal surfaces were determined to be caries free by macroscopic examination. Sample groups were divided into: (1) control (no treatment); (2) infrared diode laser irradiation (lambda = 810 nm, 68 nm, 60 mW/mm(2), 30 W) using the photo-absorbing agent alone (IRDL + PA; 500 J/cm(2)); and (3) infrared diode laser irradiation using a photo-absorbing agent combined with 2% fluoride (IRDL + PFA; 500 J/cm(2)). Buccal surfaces were evaluated following standard scanning electron microscopy preparation techniques. Control samples of enamel surfaces were relatively smooth but presented occasional enamel prism ends. There were no areas with cavitations or surface defects. RESULTS: After the IRDL + PA treatment, irradiated surfaces became rough and mildly to moderately irregular with scarce enamel cavitations and without exposure of enamel prism ends. The surfaces had adherent granules and only occasional fine cracks and porosities in surface coatings were noted. After the IRDL + PFA treatment, there was a homogenous confluent surface that masked typical enamel surface markings. The surfaces had well-defined globules resulting from the IRDL + PFA treatment, that were not seen after IRDL + PA treatment. CONCLUSIONS: Treatment of deciduous tooth enamel with infrared diode laser irradiation using a photo-absorbing agent and a photo-absorbing agent combined with 2% fluoride created surface coatings that may act as reservoirs for mineral phases during cariogenic activity on enamel, and also provide a certain degree of protection against cariogenic challenge.

Quantitative analysis of the calcium and phosphorus content of developing and permanent human teeth.

It was the aim of this study to investigate the distribution of Ca, P and C in predentin, dentin and enamel in human tooth buds and permanent teeth by EDX element analysis. The mandible of a 16-week-old human fetus containing eight mineralizing tooth buds and three human permanent molars were fixed in formaldehyde and embedded in Technovit 9100. Serial sections of 80 microm thickness of the mandible were cut in the frontal-dorsal direction, and polarized light micrographs were taken of these sections. The permanent teeth were cut in mesio-distal direction. The sections were investigated with scanning electron microscopy and EDX element analysis with a Philips XL 30 FEG scanning microscope and an EDAX energy-dispersive X-ray system using spot measurements, EDX line-scans and element mapping. Quantitative measurements were made in predentin, mineralizing dentin adjacent to predentin, mature dentin, mineralizing enamel and young enamel of developing teeth and mature enamel of permanent teeth. In developing teeth the Ca and P content increased rapidly from outer predentin towards mineralizing dentin. In enamel prisms of developing teeth the Ca and P content increased linearly from the surface towards the enamel-dentin junction. In permanent teeth only a small layer of predentin was found. The Ca and P content in enamel and circumpulpal dentin of permanent teeth was higher than in developing teeth. The Ca/P ratio differed between predentin and dentin areas reflecting different calcium phosphate compositions, but it was the same in mineralizing and young enamel. The differences in the distribution of Ca and P reflect different mineralizing patterns of the enamel and dentin matrices.

Health of infants in an Imperial Roman skeletal sample: perspective from dental microstructure.

This study examines general health in the first year of life of a population of 127 subadults from the Imperial Roman necropolis of Isola Sacra (2nd-3rd century ACE). Health status was determined by analyzing 274 deciduous teeth from these children for Wilson bands (also known as accentuated striae), microscopic defects caused by a disruption to normal enamel development arising from some generalized external stressor. While macroscopic enamel defects, or hypoplasias, have long been used as proxies of general population health, we believe that this is the first population-wide study of microscopic defects in deciduous teeth. We used microstructural markers of enamel to attach very precise chronologies to Wilson band formation that allowed us to calculate maximum prevalence (MAP) and smoothed maximum prevalence (SMAP) distributions to portray what we believe to be a realistic risk profile for a past population of children. There appear to be two periods of high prevalence, the first beginning around age 2 months and continuing through month 5, and the second higher period beginning around month 6 and continuing through month 9. These results are discussed in light of historical records of Roman childhood rearing practices.