Orientadores: Luiz Andre Freire Pimenta, Roger William Fernandes Moreira / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-04T22:40:09Z (GMT). No. of bitstreams: 1 Erhardt_MariaCarolinaGuilherme_D.pdf: 6301805 bytes, checksum: 90041cc31702b631248ac0b326fef07e (MD5) Previous issue date: 2005 / Resumo: O objetivo deste estudo in vitro foi determinar a durabilidade da interface adesiva emdentina normal (DN) ou afetada por cárie (DAC) promovida por um sistema adesivo simplificado convencional (AdperScotchbond1/ SB)e dois sistemas autocondicionantes de dois passos(Clearfil Protect Bond / PBe AdheSE/ AD), após24 horas(24h)ou 6 meses(6me)de imersão em água.Para o teste de microtração,90 molares humanos cariados foram selecionados. A superfície dentinária foi exposta através de seccionamento com disco duplo diamantado e polimento com lixas de carbeto de silício, deixando uma área central de DAC. Osdentes foram aleatoriamente divididos em 3 grupos para que recebessem a aplicação de um dos 3 sistemas adesivos, de acordo com a recomendação dos fabricantes.Blocos de compósito Tetric Ceram com altura de 4 mm foram incrementalmente confeccionados,e após 24 h de armazenagem em água destilada a 37 oC, os dentes foram seriadamente seccionados em fatias de 1,0mm de espessura paralelas ao longo eixo dental.Em seguida,dispositivos em forma de ampulheta foram confeccionados com pontas diamantadas de granulação fina em alta rotação,com área adesiva final de aproximadamente1,0 mm2, que continham DN ou DAC. Os espécimes foram armazenados em água destilada por 24h ou 6me. Decorrido este período, os espécimes foram fixados individualmente em um dispositivo de microtração (Bencor-T),acoplado em máquina de ensaio universal (Instron), para teste à 0,5 mm/min.Após o teste, a porção dentinária dos espécimes fraturados foi avaliada em um microdurômetro do tipo Knoope também observadas em microscópio eletrônico de varredura(MEV). As médias de resistência de união foram submetidos aos testes de análise de variância (ANOVA 3 fatores),StudentNewmanKeulse t de Student(p < 0,05). Cinqüenta e quatro molares cariados adicionais foram preparados da mesma maneira supradescrita. Após 24 h de armazenagem em água destilada a 37 oC,os dentes foram seccionados em fatiasde 1,0mm de espessura paralelas ao longo eixo dental. As atias foram também armazenadas em água destilada por24h ou'6me. Os espécimes de nanoinfiltração foram imersos em solução e nitrato de prata amoniacal por 24 h, lavados abundantemente imerso sem solução foto reveladora por 8 h, sobre luz fluorescente. Após o tempo de armazenagem, fatias foram recobertas com carbono para observação em MEV. Já os espécimes de tricrômico de Masson foram manualmente polidos até que apresentassem espessura média de 3 - 5 µm, paraquefos sem corado sde acordo com as indicações da técnica histológica e visualizados em microscópio óptico. Os valores médios de microtração(MPa),foram:DN/SB/24h=42,63; DN/PB/24h= 39,18; DN/AD/24h= 28,19; DN/SB/6me= 38,43; DN/PB/6me= 39,49;DN/AD/6me=27,90;DAC/SB/24h=34,49;DAC/PB/24h=28,68;DAC/AD/24h=24,20;DAC/SB/6me= 27,76;DAC/PB/6me=24,48;DAC/AD/6me=17,24.Tantoem DNquantoem DAC,após 24h ou 6me de imersão,os sistemas SB e PB apresentaram os maiores valores de resistência de união. De uma maneira geral, maiores valores de união foram obtido sem DN, comparado à DAC.Os sistemas adesivos autocondicionantes apresentaram maior estabilidade após 6 me de armazenamento / Abstract: The purpose of this study was to investigate the durability of resin-dentin bonds to sound (SD) and caries-affected dentin(CAD)using an total-etch(Adper Scotchbon1d/ SB)or two self-etch bonding systems(Clearfil Protect Bond/ PBandAdheSE/ AD)bonding agents,after24 hours(24h)or 6 months(6mt)of storage in water.For the microtensile bond strength (Thepurposeof thisstudywasto investigatethedurabilityof resin-dentinbondstosound(SD)and caries-affected dentin(CAD)using an total-etch(AdperScotchbon1d/ SB)or two self-etch bonding systems(ClearfilProtectBond/ PBandAdheSE/ AD)bonding agents,after24hours(24h)or 6 months(6mt)of storage in water.For the microtensile bond strength(jJTBSe) valuation 90 extracted carious human molars were ground flat oclusally with wets and(SiC)papers,leaving a central region of CAD dentin surrounded by ND.The teeth were randomly assigned into three groups,according to he bonding system used. All bonding systems were applied according to manufactures instructions. Resin composite (TetricCeram) build-ups were made incrementally. After storage in distilled water at 37°C for 24 h, teeth were erially sectioned into1.0mms labs,and trimmed to yield a 1.0mm2 bonded area that contained either NDor CAD.Experimental hlourglas specimens were stored in water for 6 mt. Specimens that had been store din water for 24 hwere use das controls.Specimens were individually attached to a microtensile device(Bencor-T) which was coupled to an Instron machine and tested at a crosshead speed of 0.5 mm/min.The dentin surfaces of the fractured specimens were evaluated using Knoop microhardness test and observed by scanning electron microscopy( SEM).Data were analyzed by ANOVA,Student Newman Keulsandt Student multiple comparison tests (p < 0.05). Additional 54 extracted carious human molars were prepared for nanoleakage and Masson'strichrom evaluation as described above. After storage in distilled water at 37°Cfor24h, teeth were serially sectioned into1.0mm slabs that contained NDor CAD.Slabs were store dinwater for 24 h or 6 mt.The specimens for nanoleakage were immersed in ammoniacal silver nitrate for 24 h, rinsed thoroughly and placed in photo developing solution for 8 h under fluorescent light. Slabs weres putter-coated with carbon and observed under SEM.Trichrome specimens were manually polished to 3 - 5 µm thin sections of the adhesive/denti interface and stained with the histologica dyes.Stained thin sections from each prepared tooth were imaged with optical microscopy. The µTBS mean values obtained(MPa)were:ND/SB/24h4=2.63;ND/PB/24h= 39.18; ND/AD/24h=28.19; ND/SB/6mt=38.43; ND/PB/6mt=39.49; ND/AD/6mt=27.90; CAD/SB/24h3=4.49;CAD/PB/24h2=8.68;CAD/AD/24h2=4.20;CAD/SB/6m2t=7.76;CAD/PB/6mt= 24.48;CAD/AD/6mt= 17.24.SBandPB presented the higher µTBS values,irrespective of dentin type.Regarding bond strengths obtained with all bonding systems evaluated, it could be always observed higher mean values for ND.Self-etching bonding agents presented a higher stability after 6 mt water immersion / Doutorado / Dentística / Doutor em Clínica Odontológica

Orientador: Luis Alexandre Maffei Sartini Paulillo / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-07-25T05:36:54Z (GMT). No. of bitstreams: 1 Pereira_GiseleDamianadaSilveira_M.pdf: 6881862 bytes, checksum: 025b37d2970888f849e6c9a21a3db961 (MD5) Previous issue date: 1999 / Resumo: O objetivo deste estudo foi avaliar a influência dos métodos de secagem da dentina na resistência às forças de cisalhamento de dois sistemas adesivos dentinários. Foram utilizadas as superfícies vestibular, lingual ou palatina em dentina de 105 terceiros molares íntegros recém-extraídos e armazenados em solução de formol a 10% com pH neutro. Após o condicionamento com ácido fosfórico a 35% por 15 segundos e lavagem com jatos de água por 20 segundos, foram empregados sete métodos de secagem dentinária: jatos de ar por 30 segundos (grupos 1 e 2); jatos de ar por 5 segundos (grupos 3 e 4); sem secagem (dentina sobremolhada, grupos 5 e 6); bolinhas de algodão seco (grupos 7 e 8); bolinhas de algodão úmido (grupos 9 e 10); esponja (pincel tipo "microbrush", grupos 11 e 12) e papel absorvente (grupos 13 e 14). Em seguida, o sistema adesivo Prime & Bond 2.1 foi aplicado nos grupos ímpares e nos grupos pares utilizou-se o sistema adesivo Scotchbond Multi Uso. Cilindros com 3mm de diâmetro e 5 mm de altura foram confeccionados com a resina composta Z-100 na área delimitada para a adesão, obtendo um total de 210 corpos-de-prova. Após 7 dias de armazenamento em ambiente a 37 'GRAUS'C com 100% de umidade relativa, os corpos-de-prova foram submetidos ao ensaio de resistência ao cisalhamento a uma velocidade de 0,5 mm/min. O teste t-Student apontou os resultados: Grupo 9= 23,2 MPa (a), Grupo 3= 21,3 MPa (ab), Grupo 2= 19,5 MPa (bc), Grupo 10= 18,6 MPa (bc), Grupo 14= 16,3 MPa (cd), Grupo 8= 16,1 MPa (cd), Grupo 4= 14,6 MPa (de), Grupo 13= 14,0 MPa (de), Grupo 11= 13,9 MPa (de), Grupo 7= 13,5 MPa (de), Grupo 12= 12,1 MPa (e), Grupo 1= 8,2 MPa (f), Grupo 5= 2,7 MPa (g), Grupo 6= 2,4 MPa (g). Através da análise estatística concluiu se que os valores de adesão para o sistema Prime & Bond 2.1 foram estatisticamente maiores quando esse adesivo foi aplicado nas superfícies dentinárias deixadas úmidas pelo método de secagem. Por outro lado, médias satisfatórias de resistência ao cisalhamento. para o sistema Scotchbond Multi Uso foram obtidas quando este foi aplicado ao substrato seco, contudo, esses valores não apresentaram diferença estatística significativa para os resultados dos grupos onde a dentina permaneceu; mais úmida após sua secagem. Ambos os adesivos apresentaram uma menor resistência adesiva quando aplicados ao substrato sobremolhado, onde nenhum método de secagem foi empregado / Abstract: The aim of the present study was to evaluate the shear bond strength of two adhesive systems when applied to dentin with different degrees of wetness. Buccal, lingual and palatine surfaces of 105 intact third molars recently extracted and stored in 10% formaline were utilized. After conditioning with 35% acid phosphoric for 15 seconds, seven methods of drying dentine substrate were used: Air spray for 30 seconds (Groups 1 and 2); air spray for 5 seconds (Groups 3 and 4); dry cotton pellets (Groups 7 and 8); wet cotton pellets (Groups 9 and 10); sponge (microbrush) (Groups 11 and 12); facial tissue (Groups 13 and 14); and the last group was not dried and the surfaces were left overwet (Groups 5 and 6). Thereafter, the Prime & Bond 2.1 System was applied in odd groups and the Scotchbond Multi Purpose was used in pair groups. Z-100composite cilinders with 3 mm diameter and 5mm height were built in the adhesive area (n=210). After seven days stored in a stove with 37 'DEGREE'C and 35% relative humidity, the especimens were submitted to the shear bond test in a 0,5 mm/min speed. The t-Student test presented the following results: Group 9=23.2 MPa (a); Group 3=21.3 MPa (ab); Group 2=19.5 MPa (bc); Group 10=18;6 MPa (bc); Group 14=16.3 MPa (cd); Group 8=16.1 MPa (cd); Group 4=14.6 MPa (de); Group 13=14.0 MPa (de); Group 11=13.9 MPa (de); Group 7=13.5 MPa {de}; Group 12=12.1MPa (e); Group 1-=8.2 MPa (f); Group 5=2.7 MPa (~); Group 6=2.4 MPa (g). Through the statistical analysis it was concluded that the adhesion values to Prime & Bond 2.1 were greater when this system was applied in a moister surface. On the other hand, the Scotchbond Multi Purpose showed good results to both wet and dry surfaces. The lower shear bond strength values were obtained when both adhesives were applied in a overwet surface, where the water excess was not removed. / Mestrado / Mestre em Clínica Odontológica

La maladie carieuse a pour conséquence la déminéralisation de l’émail et de la dentine et la dénaturation du collagène de la dentine. En combinant la microscopie et spectroscopie multiphotoniques, nous avons démontré que l’intensité de la fluorescence (2-Photon Excited Fluorescence = 2PEF) et de la seconde harmonique (Second Harmonic Generation = SHG) de la dentine sont fortement modifiées pendant le processus carieux et nous avons découvert que le ratio SHG/2PEF est un paramètre fiable pour suivre le processus carieux. À présent nous souhaitons évaluer la sensibilité de la méthode en déterminant les limites des signaux mesurés pour détecter les premiers stades de la lésion carieuse. Nous avons noté une modification des spectres 2PEF de l’émail (à partir d’ICDAS (International Caries Detection and Assessment System) 1) et une modification des spectres 2PEF et SHG de la dentine (à partir d’ICDAS 2) dès les premiers stades du processus carieux. Nous avons également l’intention d’étudier la modification de la structure de la dentine lors du processus carieux grâce à la variation du signal de la SHG ; et plus précisément la (ou les) causes du « shift » vers le rouge du spectre de 2PEF observé lors du processus carieux. L’objectif serait une future application de ces signaux optiques dans le diagnostic clinique cariologique. / Multiphoton microscopy and nonlinear spectroscopy is used to investigate caries process in dentin. Though a major calcified tissue of the teeth, the organic dentin phase comprises type I collagen fibers. Caries drive both dentin demineralization and collagen denaturation. Multiphoton microscopy is a powerful imaging technique because the biological materials are transparent to infrared frequencies and can be excited to penetration depths inaccessible to one photon confocal microscopy. The laser excitation greatly reduces photodamage to the sole focal region, and the signal to noise ratio is improved significantly. The method has been used to follow pathological processes involving collagen fibrosis or collagen destruction based on their 2-photon excited fluorescence (2PEF) emission and second harmonic generation (SHG). Combining multiphoton imaging with nonlinear spectroscopy we demonstrate that both 2PEF and SHG intensity of human dentin are strongly modified during tooth caries process and we discover that the ratio between SHG and 2PEF signals is a reliable parameter to follow dental caries. The ratio of the SHG/2PEF signals measured by nonlinear optical spectroscopy provides valuable information on caries process, specifically on the degradation of the organic matrix of dentin. The goal would be to bring these nonlinear optical signals to clinical application for caries diagnosis.

O objetivo desse estudo foi avaliar por meio de teste de microtração, a força de união de um sistema adesivo convencional, em dentina de dentes humanos de jovens e de idosos, alterando o tempo de condicionamento recomendado pelo fabricante. Foram utilizados doze dentes, divididos em quatro grupos, ou seja, três dentes para cada grupo, onde dois dentes foram fatiados em palitos e um dente de cada grupo foi cortado no sentido mesio-distal para observação da camada híbrida em Microscopia Eletrônica de Varredura (MEV). Foram avaliados os grupos: 1) dentes de jovens (15 a 25 anos de idade) e tempo de condicionamento de quinze segundos; 2) dentes de jovens e tempo de condicionamento de trinta segundos; 3) dentes de idosos (65 a setenta anos de idade) e tempo de condicionamento de quinze segundos e 4) dentes de idosos, com o tempo de condicionamento de trinta segundos. Para cada grupo foram confeccionados dez corpos-de-prova em forma de palitos, nos quais foram realizados condicionamento e aplicação da resina composta pela técnica incremental, com auxílio de uma matriz de aço bi partida adaptada sobre a superfície dentinária de modo que o tamanho das amostras foi padronizado A seguir foram realizados cortes seriados, paralelos ao longo eixo de cada amostra, com disco de óxido de alumínio de 150 mm de diâmetro e 0,5 mm de espessura. Um corte no sentido perpendicular ao longo eixo das amostras foi realizado para separação base acrílica do complexo dente/adesivo/resina. Esta foi composta para obtenção dos corpos-de-prova em forma de palitos, que foram fixados, com resina composta pelas extremidades ao dispositivo da máquina de ensaio, com o propósito de posicionar a área de adesão perpendicular ao longo eixo da área de tração. A seguir foram realizados testes de microtração e os resultados submetidos à análise de variância ANOVA, teste de Tuckey. Os dentes de idosos apresentaram maior força de adesão após quinze segundos de condicionamento (21,99 6,58 Mpa) seguido dos dentes de jovens condicionados por quinze segundos (17,86 3,14 Mpa). Não houve diferença significativa entre dentes de jovens (12,47 1,82 Mpa) e de idosos (12,34 0,76 Mpa) quando a dentina foi condicionada por trinta segundos. Pode-se concluir que o condicionamento ácido em dentina de dentes humanos de jovens apresentaram resultados de força de adesão maiores, com significância estatística, quando condicionados por quinze segundos a trinta segundos. O condicionamento ácido em dentina de dentes humanos de jovens apresentou resultados de força de adesão menores, com significância estatística, em relação aos dentes de idosos, quando condicionados por quinze segundos. Não houve diferença na força de adesão entre dentes de jovens e de idosos, quando a dentina foi condicionada por trinta segundos. Verificou-se que quanto maior foi a espessura da camada híbrida, maior foi a força de adesão. / The aim of this study was to evaluate through the microtraction test, the strength of the union of a conventional adhesive system in dentine of young and senior teeth, altering the time of conditioning recommended by the manufacturer. Twelve teeth were used, divided in four groups, in other words, three teeth for each group, whence two teeth were sliced until to obtain the toothpicks and one tooth of each group was cut in the medium-distal line for observation of the hybrid layer in Electronic Microscopy of Sweeping (MEV). The groups were divided in the following way: Group 1: Young teeth, using the time of conditioning recommended by the manufacturer (fifteen seconds); Group 2: Young teeth; the time of conditioning increased for thrirty seconds; Group 3: Seniors teeth, using the time of conditioning recommended by the manufacturer of fifteen seconds and Group 4: Seniors teeth, with the time of conditioning increased to thirty seconds. For each group ten test bodies were used in form of toothpicks. All the conditionings were accomplished and the application of the resin composed by the incremental technique was made, with the help of a matrix twice broken steel adapted on the dentinal surface so that the size of the samples to be standardized. Then, serial cuts were accomplished parallely to the axis lengthes of each sample, with a disk of aluminum oxide of 150 mm of diameter and 0,5 mm of thickness. A cut in the perpendicular line to the axis length of the samples made the partition of the acrylic base of the compound tooth/adhesive/resin. This base was composed to obtain the test bodies in form of toothpicks, which were fixed with an adhesive in the base of cianocrilato by the extremities to the device of the rehearsal machine, with the purpose of positioning the area of perpendicular adhesion along the axis of the traction area. To follow some tests of microtraction had been carried through and the results submitted to the analysis of ANOVA variance, the test of Tuckey. The teeth of aged people had presented greater adhesion force after fifteen seconds of conditioning (21,99 6,58 Mpa) followed of teeth of conditioned young people per fifteen seconds (17,86 3,14 Mpa). There was no significant difference among teeth of young people (12,47 1,82 Mpa) and of aged ones (12,34 0,76 Mpa) when the dentine was conditioned per thrirty seconds. It may be concluded that the acid conditioning in the human tooth dentine of young people had presented results of greater adhesion force with statistical significance, when conditioned per fifteen seconds in relation to thrirty seconds. There was no difference in the force of adhesion among the teeth of young and of aged people, when the dentine was conditioned per thrirty seconds. It was verified that the bigger the thickness of the hybrid layer the bigger the adhesion force.

Objetivo: Comparar in vitro la resistencia adhesiva a dentina de tres sistemas adhesivos universales con y sin aplicación de una sustancia neutralizadora de la capa inhibida de oxígeno. Materiales y métodos: La muestra estuvo conformada por 90 dientes bovinos, distribuidos aleatoriamente en 6 grupos (n=15): G1-Ambar™ Universal, G2-Tetric® N-bond, G3-Scotchbond™ Universal sin aplicación de sustancia inhibidora: alcohol Isopropílico y G4-Ambar™ Universal, G5-Tetric® N-bond, G6-Scotchbond™ Universal con aplicación de sustancia inhibidora. Los procedimientos adhesivos se realizaron según las indicaciones de cada fabricante y los procedimientos restauradores con cilindros (matrices tipo Tygon 4 x 2 mm) de resina compuesta Filtek™ Z350XT-A2. Las muestras fueron almacenadas en una estufa a 37°C (+/- 5°C) por 24 horas. Se evaluó la resistencia al cizallamiento a dentina en una máquina de ensayos universal Instrom (velocidad 0.5 mm/min/500N). Los resultados fueron analizados mediante estadística descriptiva (Media y desviación estándar) e inferencial (U Mann Whitney, Kruskal Wallis). Resultados: La media y desviación estándar registrada para los grupos con y sin aplicación de alcohol Isopropílico fue; Ambar™ Universal (13.7±5.7) (14.0±5.2), Tetric® N-Bond Universal (16.5±7.2) (14.2±3.9) y Scotchbond™ Universal (13.6±4.5) (18.3±7.5) respectivamente. No se encontraron diferencias estadísticamente significativas en la resistencia adhesiva a dentina de los adhesivos universales con (p=0.528) y sin (p=0.193) aplicación de la sustancia neutralizadora. Conclusión: Los valores de resistencia adhesiva a dentina de los sistemas adhesivos universales con y sin aplicación de alcohol Isopropílico como sustancia neutralizadora de la capa inhibida de oxígeno no presentaron diferencias estadísticamente significativas. / Objective: Compare in vitro bond strength to dentin of three universal adhesive systems with and without application of an oxygen-inhibited layer neutralizing substance. Materials and methods: The sample was composed by 90 bovine teeth, randomly distributed in 6 groups (n=15): G1-Ambar™ Universal, G2-Tetric® N-bond, G3-Scotchbond™ Universal without application of inhibiting substance: Isopropyl alcohol and G4-Ambar™ Universal, G5-Tetric® N-bond, G6-Scotchbond™ Universal with application of inhibiting substance. Then, the adhesive phase was made according to each group and restorative procedures with composite resin Filtek™ Z350XT-A2, according to the manufacturer´s instructions. It was made of tygon composite resin (4 x 2 mm). The samples were stored in an incubator at 37°C (+/- 5°C) for 24 hours. Subsequently, dentin shear strength was evaluated on an Instrom universal testing machine (speed 0.5 mm/min/500N load). The results were analyzed using descriptive (mean and standard deviation) and inferential (U Mann Whitney, Kruskal Wallis) statistics. Results: Mean and standard deviation registered for the groups with and without application of Isopropyl alcohol was; Ambar™ Universal (13.7±5.7) (14.0±5.2), Tetric® N-Bond Universal (16.5±7.2) (14.2±3.9) and Scotchbond™ Universal (13.6±4.5) (18.3±7.5) respectively. No found statistical significant differences between bond strength in dentin of the universal adhesives with (p=0.528) and without (p=0.193) application of the neutralizing substance. Conclusion: The values of bond strength in dentin of the universal adhesive systems with and without application of Isopropyl alcohol as neutralizing substance of the oxygen inhibited layer did not show statistically significant differences. / Tesis

Yes / Sampling of dentine for stable carbon (δ13 C) and nitrogen (δ15 N) isotope ratios in the direction of tooth growth allows the study of temporal changes to the diet and physiological stress of an individual during tooth formation. Current methods of sampling permanent teeth using 1mm increments provide temporal resolution of six - nine months at best depending on the tooth chosen. While this gives sufficient sample sizes for reliable analysis by mass spectrometry, sectioning the dentine across the incremental structures results in a rolling average of the isotope ratios. A novel method of incremental dentine collagen sampling has been developed to decrease the collagen increment size to 0.35mm along the incremental structures thus reducing averaging and improving the temporal resolution of short-term changes within the δ13 C and δ15 N values. This study presents data for a MicroMill-assisted sampling method that allows for sampling at 0.35mm width x 1mm depth increments following the incremental growth pattern of dentine. A NewWave MicroMill was used to sample the demineralised dentine section of modern donated human third molars from Sudan and compared to data from the same teeth using the 1mm incremental sectioning method 2 from Beaumont et al. (2013). The δ13 C and δ15 N isotopic data showed an increased temporal resolution, with each increment providing data for two-four months of dentine formation. The data show the potential of this method for studying dietary reconstruction, nutritional stress, and physiological change with greater temporal resolution potentially to seasonal level and with less attenuation of the δ13 C and δ15 N values than was previously possible from human dentine.

No / Incremental dentine analysis utilizes tissue that does not remodel and that permits comparison, at the same age, of those who survived infancy with those who did not at high temporal resolution. Here, we present a pilot study of teeth from a 19th-century cemetery in London, comparing the merits of two methods of obtaining dentine increments for subsequent isotope determination. Covariation in ¿13C and ¿15N values suggests that even small variations have a physiological basis. We show that high-resolution intra-dentine isotope profiles can pinpoint short-duration events such as dietary change or nutritional deprivation in the juvenile years of life.

No / Stable isotope analysis has provided crucial new insights into dietary change at the Neolithic transition in north-west Europe, indicating an unexpectedly sudden and radical shift from marine to terrestrial resources in coastal and island locations. Investigations of early Neolithic skeletal material from Sumburgh on Shetland, at the far-flung margins of the Neolithic world, suggest that this general pattern may mask significant subtle detail. Analysis of juvenile dentine reveals the consumption of marine foods on an occasional basis. This suggests that marine foods may have been consumed as a crucial supplementary resource in times of famine, when the newly introduced cereal crops failed to cope with the demanding climate of Shetland. This isotopic evidence is consistent with the presence of marine food debris in contemporary middens. The occasional and contingent nature of marine food consumption underlines how, even on Shetland, the shift from marine to terrestrial diet was a key element in the Neolithic transition.

Yes / Objectives Studies of the carbon and nitrogen stable isotope ratios (δ13C and δ15N) of modern tissues with a fast turnover, such as hair and fingernails, have established the relationship between these values in mothers and their infants during breastfeeding and weaning. Using collagen from high-resolution dentine sections of teeth which form in the perinatal period we investigate the relationship between diet and physiology in this pivotal stage of life. Materials and Methods Childhood dentine collagen δ13C and δ15N profiles were produced from horizontal sections of permanent and deciduous teeth following the direction of development. These were from two 19th-century sites (n = 24) and a small number (n = 5) of prehistoric samples from Great Britain and Ireland. Results These high-resolution data exhibit marked differences between those who survived childhood and those who did not, the former varying little and the latter fluctuating widely. Discussion Breastfeeding and weaning behavior have a significant impact on the morbidity and mortality of infants and the adults they become. In the absence of documentary evidence, archaeological studies of bone collagen of adults and juveniles have been used to infer the prevalence and duration of breastfeeding. These interpretations rely on certain assumptions about the relationship between isotope ratios in the bone collagen of the adult females and the infants who have died. The data from this study suggest a more complex situation than previously proposed and the potential for a new approach to the study of maternal and infant health in past populations.

Yes / Background: stable isotope ratios of carbon (δ13C) and nitrogen (δ15N) in bone and dentine collagen have been used for over 30 years to estimate palaeodiet, subsistence strategy, breastfeeding duration and migration within burial populations. Recent developments in dentine microsampling allow improved temporal resolution for dietary patterns. Aim: We propose a simple method which could be applied to human teeth to estimate chronological age represented by dentine microsamples in the direction of tooth growth, allowing comparison of dietary patterns between individuals and populations. The method is tested using profiles from permanent and deciduous teeth of two individuals. Subjects and methods: using a diagrammatic representation of dentine development by approximate age for each human tooth (based on the Queen Mary University of London Atlas) (AlQahtani et al., 2010), we estimate the age represented by each dentine section. Two case studies are shown: comparison of M1 and M2 from a 19th century individual from London, England, and identification of an unknown tooth from an Iron Age female adult from Scotland. Results and conclusions: The isotopic profiles demonstrate that variations in consecutively-forming teeth can be aligned using this method to extend the dietary history of an individual, or identify an unknown tooth by matching the profiles.