Enamel Of Primary Teeth Research Articles

Deciduous neonatal line: Width is associated with duration of delivery

The delivery-related neonatal line (NNL) appears into the enamel of primary teeth and first permanent molars at birth and is a marker of live birth process. It varies in width and its location, is different in each deciduous tooth type, and is indicative of gestation time. It is unclear which triggers determine NNL at birth. Our objective was to investigate the effect of the duration and mode of delivery on NNL width.NNL of 129 teeth, a collection derived from a long-term, prospectively followed population cohort, was measured under light microscope. Altogether, 54 sections with most optimal plane of sectioning were analysed for the duration and mode of delivery.NNL was detected in 98% of the deciduous teeth with the median width of 9.63μm (min 3.16μm, max 27.58μm). A prolonged duration of vaginal delivery was highly significantly associated with a narrower NNL (r=−0.41, p=0.0097). No significant association was found between the width of NNL and mode of delivery (p=0.36).NNL is demonstrable in virtually all deciduous teeth. The width seems to be inversely proportional to the duration of delivery. Causes of the inverse proportion are speculated to result from altered amelogenesis induced by prolonged and intensified delivery-associated stress. Further research is needed to clarify the underlying mechanisms.

Prevalence of enamel defects and association with dental caries in preschool children.

This was to evaluate the prevalence of the developmental defects of enamel (DDE) in primary teeth and its association with dental caries. A cross-sectional study with a randomised representative sample was carried out with 1101 children aged 2-5 years enrolled in public preschools (50% prevalence of DDE in primary teeth, a standard error of 3%, and a confidence level of 95%). Three calibrated dentists (K>0.62) performed clinical examination. Data collected were: sex, age, DDE (Modified DDE Index) and dental caries (WHO). Descriptive analysis, Chi-square test and multinomial logistic regression were applied for data analysis. Among children, 565 (51.3%) were boys; mean age was 3.7 (±0.9 years). The prevalence of enamel defect was 39.1%; the prevalence of diffuse opacities, demarcated opacities and enamel hypoplasia was 25.3, 19.1 and 6.1%, respectively. The prevalence of dental caries was 31.0%, with mean def-t 1.14 (±2.44). Primary teeth with enamel hypoplasia had three times the odds of having dental caries than those with absence of enamel defects (OR=3.10; 95% CI: 1.91, 5.01). The presence of enamel defects was moderate and associated with dental caries.

A radio-odontometric analysis of sexual dimorphism in deciduous dentition

ObjectiveIt has been suggested that the level of sexual dimorphism in deciduous dentition is relatively lower than that in permanent dentition. However, in sub adult skeletal remains whose osseous morphological traits of the sex have not defined yet, predicting sex on the basis of odontometric features may be the most precise technique. The aim of the present study was to assess the degree of sexual dimorphism in marginal enamel, dentin and pulp dimensions of second molar deciduous teeth in a pediatric population. Method and materialsThe present study was conducted on bitewing radiographs of 64 males and 60 females. The greatest width of enamel, dentin and pulp on mandibular and maxillary second molar deciduous teeth were measured. Student's t-test and discriminant analysis were used to compare the differences in the odontometric parameters between females and males. ResultsAmong the second molar measurements, only the maxillary pulp width did significantly discriminate the sex groups. The accuracy of sex identification of a case based on deciduous second molar tooth was approximately 68%. ConclusionsThe application of second molar deciduous teeth in sex prediction showed moderate level of sexual dimorphism. In this respect, the maxillary pulp width had the greatest amount of contribution in sex discrimination. Therefore, these odontometric traits, in conjunction with other skeletal features, can be used as a supplementary sexing tool for gender prediction in forensic anthropology.

Influence of fluorinated and iodized salt on mineral composition of deciduous teeth formed in biogeochemical deficiency of fluoride and iodide

Aim. To study the content of Ca, P, F and I in enamel and dentin composition of deciduous teeth, which are formed in fluoride and iodide deficiency, and its dynamics on the background of the 3-year consumption of fluorinated and iodized salt.Methods. The mineral composition of the deciduous teeth enamel and dentin of 6-12 years old children, born and living in conditions of biogeochemical deficiency of fluoride (0.02-0.08 ppm F in water) and iodide (0.033-0.005 ppm I in water) before and after consumption of fluorinated and iodized salt containing sodium fluoride 300±50 ppm F and potassium iodate 40±10 ppm I was studied. The first phase of the study was conducted before inclusion of fluorinated-iodized salt in the diet of schoolchildren. Using X-ray microanalysis, macro- and microelements of 47 intact deciduous teeth were studied. The contents of the four elements (Ca, P, F, and I) in three layers of enamel (the surface layer, intermediate layer, at the enamel-dentin border) and in three layers of the dentine (the layer at the enamel-dentin border, a middle layer, circumpulpal layer). The second phase of a study on the mineral composition of the enamel and dentin was conducted 3 years after the beginning of fluorinated and iodized salt consumption. 51 deciduous intact tooth were investigated.Results. 3-year consumption of table salt with the addition of sodium fluoride and potassium iodate has led to a significant increase in calcium, phosphorus in the enamel of the all teeth groups. The highest content of fluorine was registered in the molars where the level of fluorine increased by 2.08 times from baseline. The fluorine level in canines increased by 1.76 times from baseline, in incisors - by 1.69 times. The iodine content in the enamel increased approximately 2-fold (incisors - 1.77 times, canines - 1.89 times, molars - 1.85 times), in the dentin, depending on the teeth groups, increase in the studied parameter was by 3.12-3.51 times.Conclusion. 3-year consumption of fluorinated and iodized salt containing sodium fluoride 300±50 ppm F and potassium iodate 40±10 ppm I stimulates increasing the content of Ca, P, F and I in the enamel and the dentin of deciduous teeth formed in fluoride and iodide deficiency.

Developmental defects of enamel in primary teeth - findings of a regional German birth cohort study

BackgroundThe aim was to assess the prevalence, distribution and associated risk factors of developmental defects of enamel (DDE) in 3-year-old Thuringian children in 2013 as part of a prospective cohort study.MethodsThe subjects (n = 377) were all participants in a Thuringian oral health programme. Children of the birth cohort 2009/2010 were invited to dental examination in the first year of life, followed up with continuous dental care over the next 3 years. Dental caries was scored using the WHO diagnostic criteria expanded to the d1-level without radiography. Enamel defects were assessed according to the modified DDE Index. Data were analysed statistically (multivariate logistic regression).ResultsThe children were aged 3.3 ± 0.7 years and 52.5 % of them were male. Caries prevalence was 15.6 % and caries experience 0.9 ± 3.3 d1-4mfs. The prevalence of DDE was 5.3 % with an average of 2.7 (±1.4) affected teeth. Second primary molars were the most affected teeth and demarcated opacities the most prevalent type. No child had Amelogenesis imperfecta and six children showed hypomineralised second primary molars. Enamel defects were associated with preterm birth (p = 0.024; OR = 4.9) and hospitalisation in the first year of life (p = 0.013; OR = 4.6).ConclusionA relatively small proportion of 3-year-old Thuringian children suffered from DDE, with second primary molars as the most affected teeth and demarcated opacities as the most prevalent type of defect. Preterm birth and hospitalisation in first year of life can be considered as risk factors for DDE in the primary dentition.Trial RegistrationGerman Clinical Trials Register, DRKS00003438

Approaches adopted by dentists for management of occlusal caries in primary teeth

ABSTRACT Objective To evaluate the approaches used by Family Health Strategy dentists in the city of Campina Grande, Paraíba, Brazil, for management of occlusal caries in primary teeth. Methods In this observational, cross-sectional, census-based, descriptive study, 33 professionals completed a questionnaire designed to evaluate their approach to management of occlusal caries in enamel and dentin of deciduous teeth in different risk situations. Data were analyzed through descriptive and inferential statistics (Fisher's exact test with the level of significance set to 5%). Inter-examiner agreement was evaluated by Cohen's kappa statistic. Results For chronic enamel caries in primary teeth with low risk/activity, the approach of choice was preventive, with fluoride application being the most cited intervention (39.3%). For active carious dentin in primary teeth with high risk/activity and with low risk/activity, invasive approaches were most prevalent (93.9% and 78.8%, respectively), with complete caries removal (74.2%) and glass-ionomer restoration (69.2%) being the most frequent responses. Inter-examiner agreement was moderate (k = 0.44). Conclusion Although a wide range of approaches were adopted by dental practitioners, most preferred invasive interventions, even in situations where preservation of tooth structure was recommended.

Comparison of fluoride uptake of three fluoride varnishes on primary teeth enamel

Comparison of fluoride uptake of three fluoride varnishes on primary teeth enamel

THE EFFECT OF CCP-ACP ON THE SURFACE MICROHARDNESS OF PRIMARY TOOTH ENAMEL ERODED BY ANTIHISTAMINE SYRUP (IN VITRO STUDY)

INTRODUCTION: several cases of tooth erosion have been attributed to oral administration of liquid oral medications. Casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) has gained much concern in modern dentistry for having anti- erosive properties. OBJECTIVES: The aim of the study was to evaluate the effect of CCP-ACP on the surface microhardness of primary tooth enamel eroded by antihistamine syrup. MATERIALS AND METHODS: Twenty exfoliated primary teeth were collected and stored in normal saline till the beginning of the study. Then, each tooth was sectioned in a buccolingual direction into two halves, one served as study and other served as control. Specimens of both groups were immersed in antihistamine syrup for 30 min twice daily for 12 days to produce erosive enamel lesions. Study group specimens were treated with the remineralizing agent CPP-ACP once daily 3min for 10 consecutive days and the control group specimens remained untreated. The samples were stored in artificial saliva between the erosive and the remineralizing cycles. the samples were evaluated for their surface microhardness by using Vickers microhardness testing. Data were collected, tabulated and statistically analyzed by using paired t test. Significance level was set at 5%. Bar charts were used for graphical presentation. RESULTS: The mean surface microhardness of the sample was significantly decreased after erosion with antihistamine syrup (P<0.000). The mean surface microhardness of remineralized samples was significantly higher than that of the untreated samples (P = 0.01). CONCLUSION: Treatment of eroded primary tooth enamel with CPP-ACP paste improved the surface microhardness invitro. Hardness testing is an accurate and reliable method to evaluate the enamel surface for demineralization and remineralization studies in vitro. KEY WORDS: Dental erosion, CCP-ACP, Vickers microhardness.

Remineralization Effects on the Demineralized Enamel of Primary Teeth by Fluoride Varnish

본 연구는 탈회 ìœ ì „ì¹˜ì— 3가지 불소바니쉬를 이용하여 인공우식의 재광화 효과를 비교 평가하였다. 인공우식용액에 40개의 ê±´ì „í•œ ìœ ì „ì¹˜ 시편을 ì¹¨ì ì‹œí‚¨ 후, 37℃ 항온기에 7일 동안 보관하여 ìœ ì „ì¹˜ì— 탈회를 형성하였다. Cavity shield™, V varnish™, MI varnish™를 1주일에 한 번씩 3주 동안 탈회된 ìœ ì „ì¹˜ì— 도포 후 불소바니쉬 ì¢ ë¥˜ì— 따른 미세경도 변화를 평가하였다.1주차에서는 MI varnish™군이 가장 높은 재광화 효과를 ë³´ì˜€ê³ ë‹¤ìŒìœ¼ë¡œ V varnish™군이 높았으며, Cavity shield™군이 낮은 재광화 효과를 보였으며, 세 êµ° 모두 ìœ ì˜í•œ 차이는 없었다(p > 0.05).2주차에서는 V varnish™군이 가장 높은 재광화 효과를 보였으며 ê·¸ 다음으로 MI varnish™군 높았지만 V varnish™군과 ìœ ì˜í•œ 차이는 없었다(p > 0.05). Cavity shield™군은 V varnish™군과 MI varnish™군에 비해 ìœ ì˜í•˜ê²Œ 낮은 재광화 효과를 보였다(p < 0.05). 3주차에서는 V varnish™군이 나머지 두 êµ°ê³¼ ìœ ì˜í•œ 차이를 보이며 가장 높은 재광화 효과를 ë³´ì˜€ê³ (p < 0.05), 다음으로 MI varnish™군이 높았으며 Cavity shield™군이 가장 낮은 재광화 효과를 보였지만, MI varnish™군과의 ìœ ì˜í•œ 차이는 없었다(p > 0.05). 총 미세경도 증가량은 Cavity shield™군에 비해 V varnish™군과 MI varnish™군이 높았으며(p < 0.05), V varnish™군과 MI varnish™군 사이 í†µê³„í•™ì  ìœ ì˜í•œ 차이는 없었다(p > 0.05).

Effect of laser preparation on adhesion of a self-adhesive flowable composite resin to primary teeth.

The aim of the study was to evaluate the adhesion of a self-adhering flowable composite resin to primary tooth enamel and dentin after silicon carbide paper (SiC) and laser pretreatment. Adhesive properties were evaluated as shear bond strength (SBS) and scanning electron microscopic (SEM) characteristics. A total 120 primary canine teeth were randomly divided into two groups to study enamel and dentin. Each group was divided into 6 subgroups (n = 10) according to type of surface preparation (SiC or Er:YAG laser) of enamel or dentin. Three methods were used to build cylinders of restoration on tooth surface: OptiBond All-In-One + Premise Flowable composite, OptiBond All-In-One + Vertise Flow and Vertise flow. After restoration, samples were tested for SBS and failure mode. Twenty eight samples were examined by SEM. The results of the study showed SBS of Vertise Flow was lower than others in enamel and dentin samples pretreated with SiC and in dentin samples pretreated with laser (P < 0.001). Compared to SiC pretreatment, laser pretreatment led to a significantly higher SBS with Vertise Flow on enamel (P < 0.001). Vertise Flow associated with the adhesive led to a higher SBS in enamel and dentin compared to Vertise Flow alone. Adhesive and mixed failure modes were observed more frequently in Vertise Flow groups. SEM images showed that Vertise Flow led to more irregularities on enamel and more open dentinal tubules after laser ablation compared SiC pretreatment.

Microscopic structure of dental hard tissues in primary and permanent teeth from individuals with Prader-Willi syndrome

Objectivesevere tooth wear, in terms of both erosive wear and attrition, is a significant problem in individuals with Prader-Willi syndrome (PWS). The purpose of the present study was to describe the structure of enamel and dentine in primary and permanent teeth from individuals with PWS. Designthirty-two primary and 10 permanent teeth representing 16 individuals with PWS were investigated in the study. The enamel surface was studied using scanning electron microscopy (SEM). The microscopic structure of enamel and dentine was studied using SEM, microradiography and light microscopy. Resultsthe microscopic structure of enamel and dentine was found to be normal with the exception of a slight increase of interglobular dentine (IGD). Severe erosive defects were observed in primary teeth and also in permanent teeth with long exposure to the oral environment. Conclusionthe erosive enamel defects in individuals with PWS seem more related to the factors in the oral environment than to enamel structure which appeared normal. The occurrence of IGD indicate deficient mineralization but is probably of minor clinical significance. Gastro-oesophageal reflux is worthy of further investigation in individuals with Prader-Willi syndrome.

Tracing fetal and childhood exposure to lead using isotope analysis of deciduous teeth

We report progress in using the isotopic composition and concentration of Pb in the dentine and enamel of deciduous teeth to provide a high resolution time frame of exposure to Pb during fetal development and early childhood. Isotope measurements (total Pb and 208Pb/206Pb, 207Pb/206Pb ratios) were acquired by laser ablation inductively coupled mass spectrometry at contiguous 100 micron intervals across thin sections of the teeth; from the outer enamel surface to the pulp cavity. Teeth samples (n=10) were selected from two cohorts of children, aged 5–8 years, living in NE England. By integrating the isotope data with histological analysis of the teeth, using the daily incremental lines in dentine, we were able to assign true estimated ages to each ablation point (first 2–3 years for molars, first 1–2 years for incisors+pre-natal growth). Significant differences were observed in the isotope composition and concentration of Pb between children, reflecting differences in the timing and sources of exposure during early childhood. Those born in 2000, after the withdrawal of leaded petrol in 1999, have the lowest dentine Pb levels (<0.2µgPb/g) with 208Pb/206Pb (mean ±2σ: 2.126–2.079) 208Pb/206Pb (mean ±2σ: 0.879–0.856) ratios that correlate very closely with modern day Western European industrial aerosols (PM10, PM2.5) suggesting that diffuse airborne pollution was probably the primary source and exposure pathway. Legacy lead, if present, is insignificant. For those born in 1997, dentine lead levels are typically higher (>0.4µgPb/g) with 208Pb/206Pb (mean ±2σ: 2.145–2.117) 208Pb/206Pb (mean ±2σ: 0.898–0.882) ratios that can be modelled as a binary mix between industrial aerosols and leaded petrol emissions. Short duration, high intensity exposure events (1–2 months) were readily identified, together with evidence that dentine provides a good proxy for childhood changes in the isotope composition of blood Pb. Our pilot study confirms that laser ablation Pb isotope analysis of deciduous teeth, when carried out in conjunction with histological analysis, permits a reconstruction of the timing, duration and source of exposure to Pb during early childhood. With further development, this approach has the potential to study larger cohorts and appraise environments where the levels of exposure to Pb are much higher.

Comparative evaluation of shear bond strength of three flowable compomers on enamel of primary teeth: An in-vitro study.

BackgroundThe aim of the present study was to determine Shear bond strength (SBS) of different flowable compomers on the enamel surface of primary teeth. The null hypothesis to be tested was that none of the flowable compomer would differ significantly from the other two with respect to SBS. As a result, the tested materials that have the easiest application on child patient is preferred.Material and MethodsSixty newly extracted non carious primary molars were selected. The buccal surface was cleaned and polished to obtain a flat enamel surface. The specimens were randomly divided into three groups of 20 teeth each, based on the flowable compomers applied, as follows: group I: Dyract Flow® (Dentsply, Konstanz, Germany); group II: Twinky Star Flow® (Voco, Cuxhaven, Germany); and group III: R&D Series Nova Compomer Flow® (Imicryl, Konya, Turkey).ResultsSBS in group II (6.78± 0.45 MPa) were significantly lower than groups I and III (8.30 ± 0.29 and 8.43 ± 0.66 MPa, respectively) (P<.001). No significant difference was found between groups I and III (P<.05).ConclusionsSignificant differences existed between the SBS of the groups. Therefore, the null hypothesis was rejected. Flowable compomers can provide adequate SBS with self-etching system at restoration of primary teeth. Thus, successful restorations in pediatric patients can be done in a practical way. Key words:Flowable compomer, primary teeth, shear bond strength.

Effect of whitening toothpastes on bonding of restorative materials to enamel of primary teeth.

The aim of this in vitro investigation was to measure shear bond strength (SBS) of a resin composite and a resin-modified glass ionomer to enamel of primary teeth after application of different whitening toothpastes (WTs). Eighty labial enamel surfaces of primary incisors were randomly distributed into 8 groups of 10 each according to the surface treatment and bonding material. G1 and G2, control (brushed with water without WT); G3 and G4, (brushed with Colgate Optic White WT [Colgate-Palmolive Company, New York, NY, USA]), G5 and G6, (brushed with Crest Pro-Health Whitening WT [Procter and Gamble, Cincinnati, OH, USA]) and G7 and G8, (brushed with Arm and Hammer Advance White Extreme Whitening with Stain Defense WT [Church and Dwight Co., Princeton, NJ, USA]). SBS was measured at a crosshead speed of 0.5 mm/min and the type of bond failure was assessed using a stereomicroscope. There was significant difference between SBS of composite resin in groups 1, 3, 5, and 7 (P < 0.001), but no difference between resin-modified glass ionomer in groups 2, 4, 6, and 8 (P < 0.056). SBS of group 1 (control) was greater than groups 3, 5, and 7. There was a significant difference between group 1 and group 2 as well as group 7 and group 8 (P < 0.001). WTs affect SBS of resin composite, but not resin-modified glass ionomer to enamel of primary teeth. No difference of failure modes between different groups of tested materials.

AMELOGENEZİS İMPERFEKTA: SINIFLAMA, TEŞHİS VE TEDAVİ (DERLEME)

Amelogenesis imperfecta (AI) is a genetic abnormality of enamel development that shows hereditary transmission and affects the structure, amount and composition of the primary and permanent teeth enamel. Phenotypically this disease can be classified into four main types; hypoplastic, hipocalcified, hipomature and taurodontism observed with hipomature-hypoplastic. The negative effects of amelogenesis imperfecta on aesthetics, function, occlusion, phonation and gingival health of primary and permanent teeth produces a different approach than conventional dental treatment. In this article, classification,diagnosis and treatment of amelogenesis imperfecta cases is aimed to search

Morphological changes in the surface of enamel of primary teeth after application of ozone gas

Morphological changes in the surface of enamel of primary teeth after application of ozone gas

Shear bond strength of different types of adhesive systems to dentin and enamel of deciduous teeth in vitro.

The present study aimed to evaluate the suitability of self-etch adhesives for restoration of deciduous teeth compared with etch and rinse approaches. One hundred twenty primary teeth were divided into five groups, each being assigned to an adhesive system. Self-etch adhesives XenoV (XV) and Clearfil S(3) Bond (CB), Prime&Bond NT with (PBE)/without preliminary etching (PBN), and Optibond FL (OBFL) as an etch and rinse system were included. Enamel and dentin specimens were prepared (n=36/group), adhesives applied, and compomer cylinders polymerized. After 24-h storage in 37°C distilled water and thermo-cycling (1440cycles, 5/55°C, 27s), shear bond tests and fracture mode classification based on SEM investigation were performed. Statistical analysis involved ANOVA and Scheffé procedure with Bonferroni-Holm correction (p≤0.005). High shear bond strengths to primary enamel were determined for PBE (mean [M]=22.48±7.7MPa)>OBFL (M=19.06±5.62MPa)>CB (M=17.6±6.55MPa), and XV (M=16.85±5.38MPa) and PBN (M=8.26±4.46MPa) formed significantly less reliable enamel-resin interfaces (p≤0.005). PBE generated the highest bond strength on primary dentin (M=21.97±8.02MPa); significantly lower values were measured for XV (M=13.44±5.43MPa) and OBFL (M=12.92±4.31MPa) (p≤0.005). Adhesives requiring preliminary etching ensure optimal bond strength to primary enamel. If separate etching is to be avoided, selected self-etch adhesives obtain acceptable shear bond values on primary enamel and dentin. The treatment of pediatric patients presents a great challenge in dental practice, and optimization of treatment processes is important.

The erosive effects of honey, molasses and orange juice on the primary teeth of children

Background and aimThe objective of this study is to investigate whether or not the surface properties of the primary tooth enamel is affected by erosive foods frequently given to children by their mothers at breakfast. Materials and methodsIn our study, the materials used consisted of honey, molasses and orange juice as acidic foods and 60 primary teeth for tooth material. The samples belonging to Group 1 (n = 20) were kept within 20 ml of honey for 10 min, while those of Group 2 (n = 20) were kept within 20 ml of molasses for 10 min, and those of Group 3 (n = 20) were kept within 20 ml of orange juice, again for 10 min. Afterwards, all the samples were kept in 20 ml of saliva (pH = 6.8) for 60 min. These cycles were repeated 180 times in order to simulate the oral environment. The enamel surface roughness values of the samples were examined in the profilometry device at baseline and after procedure. ResultsThe most effective change on the surface roughness was seen to have been in the samples kept in the orange juice and molasses. It was determined that there was no statistically significant difference in the group where honey was applied (p = 0.624), whereas a statistically significant difference was seen in the group where both molasses (p = 0.017) and orange juice (p = 0.012) were applied. ConclusionIt is considered that the foods with erosive potential which are frequently given to children by mothers affect the surface properties of primary teeth at different rates.

Chemical and Morphological Changes of Primary Teeth Irradiated with Nd:YAG Laser: An Ex Vivo Long-Term Analysis.

The aim of this study was to assess any long-term chemical and morphological Nd:YAG laser modifications on irradiated primary enamel. Previous studies on irradiated primary human enamel employed methodologies that evaluated the short-term effects only. One hundred and eighty-six irradiated (with and/or without fluoride) primary enamel teeth from high-caries-risk children, which were exfoliated over a 1-year period, were collected, and the sample surface area was submitted for scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and X-ray energy-dispersive spectrometry (EDS). The subsurface was analyzed by Knoop microhardness and light microscopy (LM). Data were analyzed by one way ANOVA and Tukey tests (α=0.05) and Kruskall-Wallis and Tukey tests (α=0.05). FTIR analysis revealed a higher concentration of phosphate and carbonate in the irradiated (0.987±0.064) and lower concentration in the control groups (1.477±0.310). SEM analysis showed that the control samples exhibited a slightly smoother surface than the irradiated groups. The EDS analysis did not show any differences in the amount of calcium, phosphorus, or fluoride among the groups. The microhardness analysis revealed that sealant (249.86±7.15) and laser irradiation (262.44±22.69) led to higher hardness values than the negative control group (128.35±25.19). LM indicated significantly reduced caries formation in the laser (5.35±5.38%) and the laser plus acidulated phosphate fluoride (APF) groups (10.35±0.88%) compared with the negative control group (72.56±12.86%). Even with the limitations of the present study, these results suggest that Nd:YAG irradiation clinically modified the chemical composition of the enamel surface regardless of fluoride concentration, which successfully inhibited demineralization of primary tooth enamel over a 1-year period without significant morphological changes.

Accentuated lines in the enamel of primary incisors from skeletal remains: A contribution to the explanation of early childhood mortality in a medieval population from Poland

Physiological disruptions resulting from an impoverished environment during the first years of life are of key importance for the health and biological status of individuals and populations. Studies of growth processes in archaeological populations point to the fact that the main causes of childhood mortality in the past are to be sought among extrinsic factors. Based on this assumption, one would expect random mortality of children, with the deceased individuals representing the entire subadult population. The purpose of this study is to explore whether differences in early childhood survival are reflected in differences in deciduous tooth enamel, which can provide an insight into the development of an individual during prenatal and perinatal ontogeny. Deciduous incisors were taken from 83 individuals aged 2.0-6.5 years from a medieval inhumation cemetery dated AD 1300-1600. Prenatal and postnatal enamel formation time, neonatal line width, and the number of accentuated lines were measured using an optical microscope. The significantly wider neonatal line and the higher frequency of accentuated lines in the enamel of the incisors of children who died at the age of 2-3 years suggest the occurrence of stronger or more frequent stress events in this group. These results indicate that in skeletal populations mortality was not exclusively determined by random external factors. Individuals predisposed by an unfavorable course of prenatal and perinatal growth were more likely to die in early childhood.