Clinical Comparison of Eggshell Derived Calcium Hydroxyapatite with Dycal® as Indirect Pulp Capping Agents in Primary Molars

Abstract Objective: To evaluate and compare the efficacy of eggshell derived calcium hydroxyapatite with Dycal® as indirect pulp capping material in primary molars. Material and Methods: A total of 32 carious primary molars from 22 children (6-10-years) were screened, of which 26 primary molars meeting inclusion criteria were selected and equally divided into two groups. At the first appointment, the infected dentin was excavated using a spoon excavator after treating the carious part with Carie-Care™ chemomechanical caries removal agent. After this, eggshell derived calcium hydroxyapatite in Group 1 and Dycal® in Group 2 were used as liners followed by restoration of the cavity with type IX glass ionomer cement. Clinical assessment for pain and radiographic assessment for measurement of the amount of reparative dentin thickness formation was performed at baseline, 8 weeks and 3 months. The data were subjected to statistical analysis by one-way ANOVA and Kruskal-Wallis tests. Results: Higher mean reparative dentin formation was found in eggshell derived calcium hydroxyapatite group than Dycal® group at the end of 8 weeks and 3 months and the difference was significant statistically (p<0.001). Conclusion: Eggshell derived calcium hydroxyapatite seems to be a suitable alternative to Dycal® (calcium hydroxide) that can be used as a liner for indirect pulp capping in primary molars.

Reparative dentin formation using stem cell therapy versus calcium hydroxide in direct pulp capping: an animal study

Abstract Direct pulp capping process is a therapeutic method aimed at maintenance of pulp vitality and health by using a biocompatible material placed directly over the exposed pulp. The aim of this study was to evaluate and compare the effect of direct pulp capping procedures by dental pulp stem cells (DPSCs) or calcium hydroxide on dentin tissue formation. Three mongrel dogs were used as experimental model. Two access cavities were prepared in the right and left mandibular fourth premolars in all dogs to expose and extirpate the pulp tissues which were processed in the lab to obtain a single-cell suspensions. The isolated cells were cultures in odontogenic medium for subsequent differentiation. The maxillary teeth (3 incisors and one canine) of the corresponding dog number were subjected to class V cavities to expose their pulps which were assigned into 2 groups of 12 teeth each ( group I - pulp capping with calcium hydroxide) and (group II - pulp capping with dental stem cells DPSCs). The operated teeth were collected after 3 months and processed for histological and electron microscopic examinations. Specimens were subjected to elemental analysis of calcium and phosphorus. EDX elemental analysis revealed significant differences in the calcium and phosphorous wt, % in the reparative dentin of calcium hydroxide treated group which confirmed histologically. Direct pulp capping by DPSCs has shown promising generative potential for regaining normal dentin.

Resumo O processo de capeamento pulpar direto é um método terapêutico que visa a manutenção da vitalidade e saúde da polpa, usando um material biocompatível colocado diretamente sobre a polpa exposta. O objetivo deste estudo foi avaliar e comparar o efeito do capeamento pulpar direto usando células-tronco da polpa dentária (CTPDs) ou hidróxido de cálcio sobre o tecido da dentina formação. Três cães sem raça definida foram utilizados como modelo experimental. Duas cavidades de acesso foram preparados nos quartos pré-molares inferiores direito e esquerdo em todos os cães para expor e extirpar os tecidos pulpares que foram processados ​​em laboratório para obter suspensões de uma célula única. As células isoladas foram cultivadas em meio odontogênico para posterior diferenciação. Os dentes superiores (3 incisivos e um canino) do respectivo cão foram submetidos ao preparo de cavidades classe V para expor suas polpas, as quais foram atribuídas a 2 grupos de 12 dentes cada (grupo I - capeamento pulpar com hidróxido de cálcio) e (grupo II - capeamento pulpar com CTPDs). Os dentes operados foram extraídos após 3 meses e processado para exames histológicos e por microscopia eletrônica de varredura. Os espécimes foram submetidos a análises elementares de cálcio e fósforo. Análise elementar por EDX revelaram diferenças significativas no peso de cálcio e fósforo, % na massa reparadora dentina do grupo tratado com hidróxido de cálcio, o que foi confirmado histologicamente. O capeamento pulpar com CTPDs mostrou potencial promissor para recuperar a dentina normal.

Irrigação ultrassônica passiva proporciona menor incidência de debris após preparo do espaço para o pino / Passive ultrasonic irrigation provides less debris after post space preparation

Objetivo: esse estudo avaliou a incidência de resíduos (debris) na dentina, no espaço preparado para pino de fibra, submetida a um dos seguintes protocolos de irrigação: água destilada (AD); hipoclorito de sódio a 2,5% (HS); hipoclorito de sódio a 2,5% mais EDTA a 17% (HSE); hipoclorito de sódio a 2,5% agitado com irrigação ultrassônica passiva (HSUS). Métodos: os canais radiculares de quarenta incisivos bovinos, com comprimento radicular de 17,0 mm, foram obturados pela técnica do cone único. Após sete dias, um espaço para o pino de fibra foi preparado com brocas de Largo #1 e #2 e broca DC2 (White Post; FGM). Os espécimes foram aleatoriamente distribuídos em quatro grupos (n = 10), de acordo com o protocolo de irrigação usado: AD; HS, HSE ou HSUS. As raízes foram clivadas longitudinalmente e obtidas imagens, em microscopia eletrônica de varredura (500X), da superfície dentinária dos segmentos radiculares cervical e apical do espaço preparado para pino de fibra. Escores foram atribuídos de acordo com a presença de debris. Resultados: no segmento cervical, HSE e HSUS apresentaram menor incidência de debris do que AD e HS (p < 0,05). No segmento apical, HSUS proporcionou a menor incidência de debris na dentina radicular (p < 0,05). Não houve diferença entre os demais protocolos de irrigação, tanto no segmento cervical quanto no apical (p > 0,05). Conclusões: o protocolo HSUS proporcionou menor incidência de debris sobre a superfície dentinária do espaço preparado para pino de fibra (AU).

Objective: The present study evaluated the residues (debris) incidence in dentin fiber post space submitted to irrigation protocols using distilled water (DW), 2.5% sodium hypochlorite (HS), 2.5 % sodium hypochlorite and 17% EDTA (HSE), or 2.5% sodium hypochlorite energized bypassive ultrasonic irrigation (HSUS). Methods: Forty bovine incisors root canals with standardized root length (17.0mm) were obturated using single cone technique and epoxyresin sealer. After 7 days, the fiber post space was prepared using # 1 and # 2 Largo burs, and DC2 (White Post; FGM).The specimens were randomly divided into four groups (n= 10), according to the irrigation protocol: AD; HS, HSE or HSUS. After 48 hours, the roots were sectioned. Cervical and apical segment images were obtained using scanning electron microscopy (500X). Scores were assessed according to debris presence. Results: In cervical segment, HSE and HSUS presented debris incidence lower than DW and HS (P <0.05). DW and HS or HSE and HSUS were similar to each other (P > 0.05). Conclusions: HSUS provided the lower debris incidence in dentin surface of the fiber post space (P < 0.05) (AU).

An experimental study of simvastatin-collagen composite sponge as a direct pulp capping material in rat molars / 华西口腔医学杂志

OBJECTIVE@#To assess the feasibility and efficacy of simvastatin-collagen composite sponge as a novel, direct pulp capping material.@*METHODS@#A total of 120 Sprague-Dawley rats were randomly divided into three groups: the simvastatin-collagen composite sponge group (SIM group), the collagen sponge group (CS group), and the Ca(OH)2 group (CH group). An endodontic entry cavity was prepared on the occlusion of the first molar on the left maxillary of each rat. The contralateral teeth were utilized as the normal control group. The rats were experimented after 1, 3, 7, 14, and 28 days. X-ray observations were conducted and the specimens underwent hematoxylin-eosin (HE) and Masson's Thichrome staining. Dentin bridge formations and pulpal biology reactions were evaluated histopathologically.@*RESULTS@#X-ray results: high-density images could be observed on the pulp exposure sites in the CH group on the 28th day. In the SIM group, high-density images could be observed after 14 and 28 days, whereas in the CS group, high-density images were not observable in the exposed area. HE and Masson's Thichrome staining results: different degrees of inflammation under the cavity were detected in the three groups at different time points. The inflammatory reaction of the CS group was the most serious. The degree of the inflammatory reaction varied significantly between the SIM and the CS groups on the 14th and 28th days (P<0.01). The inflammatory reaction in the SIM group was lighter than in the CH group. There was a statistical difference between the SIM and the CH groups on the 14th day (P<0.05). During the observation period, the SIM group induced the best and fastest formation of reparative dentin. As for dentin bridge formation, a significantly higher complete bridge rate was observed in the SIM group than in the CH and in the CS groups on the 14th day (P<0.05) and for the SIM and the CH groups compared with the CS group on the 28th day (P<0.05).@*CONCLUSIONS@#The simvastatin-collagen composite sponge exhibited satisfactory biocompatibility with the pulp tissue and promoted the formation of reparative dentin. The application of simvastatin-collagen composite sponge as a pulp-capping material has satisfactory potential.

The Application of Paewinsky et al.'s Age Estimation Method to Periapical Radiographs / 대한법의학회지

There have been many radiographic studies on age estimation that evaluate reduction in size of dental pulp cavity with secondary dentin formation. The Paewinsky method reported high accuracy in estimating ages by measuring the width of the pulp cavity in panoramic radiographs. The aim of this study was to evaluate the application of the Paewinsky method to digital periapical radiographs. This study was conducted on 103 cases that reported to the Section of Human Identification of the National Forensic Service. The age was calculated by applying the Paewinsky method that measures the root and pulp canal width at three points in a tooth. The estimation results were compared with those calculated by the Johanson method. When the Paewinsky models were applied to digital periapical radiographs, the errors were significantly greater as compared to the original study. The errors of the maxillary second premolar and mandibular lateral incisor were greater than those of the maxillary central incisor, lateral incisor, mandibular canine, and first premolar. Furthermore, errors of the age estimation models in level C were greater than those in levels A and B. This study could be a reference for the application of the Paewinsky method to digital periapical radiographs.

An Assessment of Radiological Age Estimation Method Using Mandibular First Molars in Korean Adults / 대한법의학회지

Age estimation is important in the practice of forensic science to establish the identity of human remains, as well as with living persons. Particularly in Korea, age estimation in adults has been increase in the demand for incorrect birth records in order to be entitled to civil liability, social benefits, employment. The reduction of pulp cavity size as a result of secondary dentin deposit with increasing age could be used to estimate age. This regressive change can be analyzed using radiological techniques; thus, a variety of methods for dental age estimation based on this approach have been proposed. The purpose of this study is to evaluate the concurrence between the Drusini's method and the Jeon's method using the mandibular first molar on orthopantomographs (OPGs) in Korean adults. A total of 232 OPGs (91 females and 141 males) of Korean individuals with ages ranging from 20 to 69 years were analyzed using Drusini's method and Jeon's method. Our results revealed that the correlation of the two methods with age was statistically significant (r=0.501). Both Drusini's method and Jeon's method showed significant correlation with chronological age, and Jeon's method showed a greater correlation with chronological age (r=0.738) than Drusini's method (r=0.586). The mean absolute error was 7.99 years for Jeon's method and 9.79 years for Drusini's method. Our results demonstrate that Jeon's method using the mandibular first molar on OPGs is a practical and suitable method for age estimation in Korean adults.

Confusion and solution for vital pulp therapy / 华西口腔医学杂志

Dental pulp tissue plays a role in forming dentin, providing nutrition, conducting pain, and generating protective responses to environmental stimuli. Bacterial infection is the main cause of pulp disease, where histopathological changes are the histological basis for determining the choice of treatment and the evaluation of therapeutic effect. Thus, particular attention should be given to eliminate infection, as well as preserve and maintain pulpal health in teeth that show reversible or limited pulpal injuries. Vital pulp therapy, especially its indications and prognostic factors, has been a research hotspot that often causes confusion among clinicians. In this paper, we briefly introduce the confusion and solution for vital pulp therapy in terms of indications, pulp condition assessment, infection elimination, and capping material selection. In addition, we develop a clinical pathway and an operation normalization of vital pulp therapy to better perform the therapy.

Dentina / Dentin

Si bien la dentina y la pulpa tienen marcadas diferencias en su composición y estructura, ambas están tan íntimamente ligadas por su origen embriológico, que cualquier cosa que afecte a la dentina lo hará sobre la pulpa y viceversa. El ejemplo más claro en ese sentido está dado por el líquido intersticial. Este líquido, semejante al plasma pero con menos proteínas, constituye una continuidad entre ambos tejidos y sus efectos hidrodinámicos son muy importantes, tanto en los estados fisiológicos como en los patológicos

Tenascin and Fibronectin Expression after Pulp Capping with Different Hemostatic Agents: A Preliminary Study

This study investigated the expression of extracellular matrix glycoproteins tenascin (TN) and fibronectin (FN) in pulp repair after capping with calcium hydroxide (CH), following different hemostasis protocols. Class I cavities with a pulp exposure were prepared in 42 human third molars scheduled for extraction. Different hemostatic agents (0.9% saline solution, 5.25% sodium hypochlorite and 2% chlorhexidine digluconate) were used and pulps were capped with CH cement. After 7, 30 or 90 days, teeth were extracted, formalin-fixed, and prepared for immunohistochemical technique. Hemostatic agents did not influence the expression of TN and FN. Both glycoproteins were found in the entire the pulp tissue and around collagen fibers, but were absent in the mineralized tissues. In the predentin, TN showed positive immunostaining and FN had a variable expression. Within 7 days post-treatment, a slightly more pronounced immunostaining on the pulp exposure site was observed. Within 30 days, TN and FN demonstrated a positive expression around the dentin barrier and at 90 days, a thin and linear expression of TN and FN was delimitating the reparative dentin. In conclusion, hemostatic agents did not influence TN and FN expression. Immunostaining for TN and FN was seen in different regions and periods, demonstrating their role in pulp repair.

Este estudo investigou a expressão das glicoproteínas Tenascina (TN) e Fibronectina (FN) da matriz extracelular no reparo pulpar após capeamento com hidróxido de cálcio (HC), seguindo diferentes protocolos de hemostasia. Cavidades de classe I com exposição pulpar foram preparadas em 42 terceiros molares humanos indicados para extração. Diferentes agentes hemostáticos (solução salina a 0,9%, hipoclorito de sódio a 5,25% e clorexidina a 2%) foram usados e as polpas foram capeadas com cimento de HC. Após 7, 30 ou 90 dias, os dentes foram extraídos, fixados em formalina e preparados para análise imunoistoquímica. Os agentes hemostáticos não influenciaram a expressão de TN e FN. Ambas glicoproteínas foram encontradas em todo tecido pulpar, ao redor das fibras colágenas e estiveram ausentes nos tecidos mineralizados. Na pré-dentina, a TN mostrou forte imunoexpressão e a FN teve uma expressão variável. Após 7 dias, foi observada uma expressão levemente mais pronunciada no lugar da exposição pulpar. Aos 30 dias, a TN e a FN demonstraram uma expressão mais forte sob a barreira dentinária e aos 90 dias, uma expressão fina e linear da TN e FN apresentava-se delimitando a dentina reparativa. Em conclusão, os agentes hemostáticos não influenciaram e expressão da TN e da FN. A imunoexpressão da TN e FN foi observada em diferentes regiões e períodos, demonstrando o seu papel no reparo pulpar.

Dentina / Dentin

Si bien la dentina y la pulpa tienen marcadas diferencias en su composición y estructura, ambas están tan íntimamente ligadas por su origen embriológico, que cualquier cosa que afecte a la dentina lo hará sobre la pulpa y viceversa. El ejemplo más claro en ese sentido está dado por el líquido intersticial. Este líquido, semejante al plasma, pero con menos proteínas, constituye una continuidad entre ambos tejidos y sus efectos hidrodinámicos son muy importantes tanto en los estados fisiológicos como en los patológicos.

Dentina / Dentin

Si bien la dentina y la pulpa tienen marcadas diferencias en su composición y estructura, ambas están tan íntimamente ligadas por su origen embriológico, que cualquier cosa que afecte a la dentina lo hará sobre la pulpa y viceversa. El ejemplo más claro en ese sentido está dado por el líquido intersticial. Este líquido, semejante al plasma, pero con menos proteínas, constituye una continuidad entre ambos tejidos y sus efectos hidrodinámicos son muy importantes tanto en los estados fisiológicos como en los patológicos.

Apical Barrier Formation After Incomplete Orthograde MTA Apical Plug Placement in Teeth with Open Apex - Report of Two Cases

Two cases are reported in which incomplete placement of 4 mm mineral trioxide aggregate (MTA) plug was performed unintentionally at the apical third of permanent immature teeth with open apex and apical periodontitis. As confirmed radiographically, there were gaps between MTA and dentinal walls along the MTA-dentin interface. After setting of MTA was confirmed, endodontic treatment was completed and access was sealed with composite resin. At 6 to 16 months follow-up examinations, formation of dentin in contact with the MTA surface, as well as apical closure and periapical healing were ideied radiographically for both cases. The results of these cases showed that apical barrier formation and complete periapical healing is possible despite the incomplete apical placement of the MTA plug. This might be due to the biological properties of the MTA. Even so, an incomplete three-dimensional placement of the filling material is not advocated.

Comparative evaluation of formocresol and mineral trioxide aggregate as pulpotomy agents in deciduous teeth.

Aim: To evaluate and compare mineral trioxide aggregate (MTA) and formocresol as pulpotomy medicaments by clinical and radiographic assessments and to assess the histological features of both pulpotomy medicaments in deciduous teeth. Materials and Methods: This study was performed on 100 mandibular deciduous molar teeth requiring pulpotomy treatment. Children between age four and six years were randomly selected and divided into formocresol or MTA group. The patients were recalled after 3, 6, 9, 12 months respectively and evaluated clinically and radiographically. Histological assessment was done on lower deciduous canine teeth, which were undergoing serial extraction for interceptive orthodontic purpose. Pulpotomy was done on four teeth with formocresol and another four teeth with MTA. The teeth were extracted after six months following pulpotomy procedure and histologically evaluated. Two freshly extracted carious teeth were taken as controls. Results: Clinical and radiographic criteria were laid and Chi analysis revealed significant difference in mobility ( P≤0.05), periodontal ligament widening ( P≤0.01 level) and inter - radicular radiolucency ( P≤0.02 level) between two groups at the end of 12 months. Histologically, in MTA group, a layer of new dentine formation with less dentinal tubules at the pulpotomized site was found. In formocresol group, increased inflammatory cells, a zone of atrophy, were noted in radicular portion of pulp. Conclusion: MTA is superior to formocresol clinically, radiographically. Histological analysis showed better reparative ability with hard tissue barrier formation with MTA compared to formocresol.

Response of human dental pulp to calcium hydroxide paste preceded by a corticosteroid/ antibiotic dressing agent

Aim: To evaluate the treatment with corticosteroid/antibiotic dressing in pulpotomy with calciumhydroxide. Methods: Forty-six premolars were pulpotomized and randomly assigned into 3groups. In Group I pulpal wound was directly capped with calcium hydroxide, and Group II and Group III received corticosteroid/antibiotic dressing for 10 min or 48 h, respectively, before pulp capping. Teeth were processed for histological analysis after 7, 30 or 60 days to determine inflammatory cell response, tissue disorganization, dentin bridge formation and presence of bacteria.Attributed scores were analyzed by Kruskal-Wallis and Mann-Whitney tests (á=0.05). Results:On the 7th day, all groups exhibited dilated and congested blood vessels in the tissue adjacent to pulpal wound. The inflammatory cell response was significantly greater in Group III (p<0.05). On the 30th day, in all groups, a thin dentin matrix layer was deposited adjacent to the pulpal wound and a continuous odontoblast-like cell layer underlying the dentin matrix was observed. On the60th day, all groups presented a thick hard barrier characterized by an outer zone of dystrophic calcification and an inner zone of tubular dentin matrix underlined by a defined odontoblast-like celllayer. Conclusions: Within the limitations of present study, considering that the treatment was performed in healthy teeth, it may be concluded that the use of a corticosteroid/antibiotic dressing before remaining tissue protection with calcium hydroxide had no influence on pulp tissue healing.

The effect of 1,25(OH)D3 deficiency in the secondary dentin formation and mineralization and caries of the mice / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To determine the role of 1,25(OH)2D3 on the secondary dentin formation and mineralization of the mice.</p><p><b>METHODS</b>The differences of the mandible mineralization between the wild-type and 1-alpha-hydroxylase gene knockout mice at 6 weeks old were assessed by hematoxylin-eosin (HE) staining, immunohistochemistry, alkaline phosphatase (ALP) histochemistry staining.</p><p><b>RESULTS</b>The ratio of caries were increased significantly, while the secondary dentin was reduced significantly, the deposition of type I collagen and osteocalcin on the secondary dentin of occlusion surface was decreased significantly, but the deposition of the Biglycan on the dentin was increased significantly, the active of ALP on the odontoblasts were reduced significantly in 1-alpha-hydroxylase gene knockout mice compared to that in the wild-type littermates.</p><p><b>CONCLUSION</b>1,25(OH)2D3 deficiency lead to a defect in the secondary dentin formation and mineralization and caries of the mice.</p>

Effects of Nd:YAG laser on micro-tensile bond strength of single bond adhesive system for non-carious sclerotic dentin / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the effect of Nd:YAG laser on microtensile bond strength of single bond adhesive system for non-carious sclerotic dentin.</p><p><b>METHODS</b>Ten human molars with occlusal wearing were cut into equal halves (nearly 12 mm(2)), and randomly divided into experimental group and control group. The teeth in experimental group were processed with Nd:YAG laser (1 W, 10 Hz), and then applied with Scotchbond and filled with Z350 resin. In control group, the teeth were processed with single bond and filled with Z350 resin. The specimens were sectioned, and the microtensile bond strengths of each sample was tested by a universal testing machine.</p><p><b>RESULTS</b>The bond strength of the experimental group [(26.11 ± 1.62) MPa] was significantly higher than that of the control group [(22.27 ± 2.16) MPa], P < 0.05. Stero-microscope examination indicated that most of the fractures occurred in dentin-resin interface.</p><p><b>CONCLUSIONS</b>Nd:YAG laser can increase the microtensile bond strength of single bond adhesive system in non-carious sclerotic dentin.</p>

Pulpotomies with portland cement in human primary molars

Two clinical cases in which Portland cement (PC) was applied as a medicament after pulpotomy of mandibular primary molars in children are presented. Pulpotomy using PC was carried out in two mandibular first molars and one mandibular second molar, which were further followed-up. At the 3, 6 and 12-month follow-up appointments, clinical and radiographic examinations of the pulpotomized teeth and their periradicular area revealed that the treatments were successful in maintaining the teeth asymptomatic and preserving pulpal vitality. Additionally, the formation of a dentin bridge immediately below the PC could be observed in the three molars treated. PC may be considered as an effective alternative for primary molar pulpotomies, at least in a short-term period. Randomized clinical trials with human teeth are required in order to determine the suitability of PC before unlimited clinical use can be recommended.

Ultrastructural study of sclerotic dentin surface following the application of the Er, Cr: YSGG laser / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the ultrastructure character of sclerotic dentin surface conditioned by the Er, Cr: YSGG laser and acid etching.</p><p><b>METHODS</b>Sixteen human teeth with sclerotic dentin were randomly assigned to 4 groups, and conditioned with acid etching (Group A), laser irradiation (Group B), laser irradiation after acid etching (Group C), or acid etching after laser irradiation (Group D) respectively. The characters of surface ultrastructure were observed using scanning electron microscope (SEM).</p><p><b>RESULTS</b>In Group A, the majority of dentin tubules were blocked by sclerotic rods. In Group B, the honeycomb-like change was found on the sclerotic dentin surface. The surface structure of Group C was similar to that of Group B. In group D etching wiped off the honeycomb-like structure.</p><p><b>CONCLUSIONS</b>The sclerotic dentin surface treated with laser irradiation turns into uniform honeycomb-like structure. The rough surface may be beneficial to bonding strength on sclerotic dentin after laser irradiation.</p>

Dentin permeability: the basis for understanding pulp reactions and adhesive technology

Permeability involves the passage of fluids, ions, molecules, particulate matter and bacteria into and through a substance or tissue under different and varying conditions. The permeability of the dentin is essential to support the physiology and reaction patterns of the pulp-dentin organ. Nutrients and impulses are transported from the pulp via the odontoblast process and the contents of its tubules maintain the dentin as a vital tissue. However, the main interest of this paper focuses on penetration from the outside towards the pulp rather than from the pulp towards the outside. The present overview centers on the dentinal tubules; how they are formed and how they change as a result of normal and abnormal function, age, and pathological processes and the effect of these processes on the permeability of dentin. Particular attention is focused on the patency of the dentinal tubules.This overview is largely based on the author’s own research, clinical insights and active participation in continuing dental education over the last 50 years. It is not a review of the literature related to the permeability of dentin. Rather it presents interpretation of results related to the permeability of dentin based on experience and opinions acquired over a lifetime in dental research.

A permeabilidade envolve a passagem de fluidos, íons, moléculas, material particulado e bactérias para o interior e através de uma substância ou tecido sob diferentes e variáveis condições. A permeabilidade da dentina é essencial para a fisiologia e para os padrões de reação do órgão dentino-pulpar. Nutrientes e impulsos são transportados a partir da polpa por meio dos processos odontoblásticos e o conteúdo dos seus túbulos mantém a vitalidade da dentina. Entretanto, o principal interesse deste artigo concentra-se na penetração do exterior para a polpa e não da polpa para o exterior. O presente artigo centra-se essencialmente nos túbulos dentinários; como eles são formados e como eles mudam em razão da função normal e anormal, idade e processos patológicos, e o efeito destes processos na permeabilidade da dentina. Especial atenção é dada à patência dos túbulos dentinários. Este artigo apresenta uma visão geral do assunto e baseia-se amplamente nas pesquisas e percepções clinicas do próprio autor e em sua ativa participação na educação odontológica continuada ao longo dos últimos 50 anos. Não se trata de uma revisão da literatura relacionada à permeabilidade dentinária, mas sim da interpretação de resultados relacionados à permeabilidade dentinária com base na experiência e opiniões formadas ao longo de toda uma vida dedicada à pesquisa odontológica.

Observing interfacial nanoleakage in sclerotic dentin bonding under confocal laser scanning microscope / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To observe sclerotic dentin bonding interfacial nanoleakage used total-etching system and self-etching system by confocal laser scanning microscope (CLSM).</p><p><b>METHODS</b>12 maxillary bicuspids with non-caries, natural cervical sclerotic lesions were divided into three groups. Artifically prepared wedge-shaped lesions were made in 12 sound maxillary bicuspids and divided into three groups as controls. Three kinds of dentin bonding agents, Single Bond (SB), Clearfil SE Bond (CB) and Xeno III (XB), were applied on the surface of the wedge-shaped lesion dentins according to the manufacturer' s instruction. The apical foramens were occluded with self-curing resin. Six specimen groups were individually exposed to 0.1% rhodamine B isothiocyanate in 50% alcohol solutions for 24 h. Then the teeth were section using slow saw and observed the specimens under CLSM.</p><p><b>RESULTS</b>Two-way ANVOA revealed significant influence of both type of the dentin substrate and the adhesive systems tested on the lengths of the dye-penetrated pathways, representing the amount of nanoleakage (P < 0.05). The lengths of the dye-penetrated pathways were longer in SB than in CB and XB, whatever in normal dentin or sclerotic dentin (P < 0.05). While the extension of nanoleakage were similar in CB and XB (P > 0.05). There was no statistical significance in the amount of nanoleakage in normal dentin and sclerotic dentin using SB (P = 0.148). In CB and XB, the amounts of nanoleakage in normal dentin were higher than in sclerotic dentin (P < 0.05).</p><p><b>CONCLUSION</b>The nanoleakage phenomena of bonding interface were observed in three bonding adhesives. In sclerotic dentin bonding interfaces, these nanoleakage phenomenon were located among resin and normal dentin as well as sclerotic dentin.</p>