Short- and long-term dental arch spatial changes following premature loss of primary molars A systematic review

Aim: The aim of this study was to evaluate the dental arch spatial changes in maxillary and mandibular arches after premature loss of primary molars. Introduction: Primary teeth must be maintained during the change from primary to mixed and then permanent dentition, to preserve and maintain the dental arch. When this normal process is disturbed, usually due to severe decay requiring extraction before normal exfoliation, it can result in migration of adjacent teeth toward the missing space resulting in decreased arch length and malocclusion in the permanent dentition. Materials and Methods: A comprehensive search was conducted using electronic databases such as PubMed Central, Cochrane Database of Systematic Reviews, Google Scholar, LILACS, and ScienceDirect. The title and abstract were screened to find relevant articles, which were then reviewed in full to see if they were worthy of inclusion. All longitudinal and observational studies that looked at space changes after the loss of primary first or second molars were included. Quality assessment of the studies was done based on the Newcastle-Ottawa scale as all the included studies were non-randomized studies. Results: Four thousand five hundred and seventy-eight articles were identified by screening electronic database and assessed for eligibility, 12 full-text articles were assessed, and 4 full-text articles were excluded as they did not match the inclusion criteria. Thus, eight articles were included in this systematic review. Short term and long term space changes and loss of maxillary and mandibular molars were studied individually. In the short term changes, the distal migration of the primary cuspid towards the missing space within 1 month was attributable to early space changes after premature loss of the mandibular first molar, and the greatest space loss was recorded in the first 3 months after premature loss. After the premature loss of the maxillary first molar, immediate space loss of 1mm was documented due to distal migration of the primary canine. Studies found that space loss was caused by the distal migration of primary canines in the case of mandibular primary first molar loss, and that space loss was larger in the mandibular arch after premature loss of second primary molars. Conclusion: The greatest repercussions occurred during the first 3 months after the deciduous molars were extracted, and a space maintainer was recommended in the majority of cases, mainly when there is premature loss of mandibular second primary molar as it leads to mesial displacement of the first permanent molar.

A cone-beam computed tomographic study of root and root canal morphology of primary maxillary and mandibular second molars in Indian Children An in vitro study

Introduction: The root canal system in primary molars is considered to be complex. The aim of the present study was to assess the morphology of roots and root canals of primary maxillary and mandibular second molars using the cone-beam computed tomography (CBCT). Materials and Methods: From a total of 104 collected primary maxillary and mandibular molars (51 maxillary second molars and 53 mandibular second molars), 60 teeth (30 each of maxillary and mandibular second molars) were selected randomly and accordingly assigned into two groups: MAX2M (primary maxillary second molars) and MAN2M (primary mandibular second molars). CBCT was used to assess the number of roots and root canals, length of root, mesiodistal and buccolingual width of the canal, shape of the canal, and intercanal communications. Descriptive statistical analysis was performed using the SPSS software version 17.0. Results: The mandibular second molars showed the presence of two roots in 27 sample molars while the presence of three roots was observed in three MAN2M group. In these molars, all three roots exhibited Type I root canal configuration. The maxillary second molars exhibited three roots. A total of nine intercanal communications were seen in MAX2M group, whereas two communications were seen in MAN2M group. The palatal root in MAX2M group was more angulated (mean value: 127.21 ± 9.10) as compared to mesial (mean value: 95.39 ± 8.64) and distal roots (114 ± 11.24). Conclusion: The comprehensive knowledge of root and canal morphology of primary molars and anatomic variations is essential for successful endodontic therapy.

Root Canal Morphology of Primary Molars – A Cone Beam Computed Tomography (CBCT) Study

Objectives: To evaluate the root and canal morphology of primary maxillary and mandibular molars in an Indian population using cone?beam computed tomography (CBCT). Methods: A retrospective cross?sectional study was performed, where CBCT scans of children less than 10 years of age taken for valid diagnostic purposes previously were considered and images were analyzed. The number of roots, root canals, and variations in morphology were recorded. Left–right symmetry was also noted. Results: A total of 433 deciduous maxillary and mandibular primary molars were studied. It was observed that two separate roots with three separate canals were common in primary mandibular first molars, whereas two separate roots with two canals in each root were common in mandibular second primary molars. In primary maxillary molars, three separate roots with one canal each were the most common. Maxillary first molars (17.21%) and 17.35% second molars had fused distobuccal and palatal roots. It was observed that primary maxillary molars showed more left–right symmetry (86.7% in first molars and 82.7% in second molars) compared to primary mandibular molars (54.05% in first molars and 68% in second molars). Conclusions: It was concluded that in both primary maxillary first and second molars, three separate roots, a mesiobuccal root, a distobuccal root, and a palatal root with one canal in each root, were the most common. Two separate roots with three separate canals were the most common in primary mandibular first molars, whereas two separate roots with two canals each in both roots were more common in mandibular second primary molars.

In vivo evaluation of clinical performance of Cention N and glass ionomer cement in proximal restorations of primary molars

Introduction: Restoring a proximal lesion in primary tooth has met with many challenges which has led to evolution of many materials. An alternative to Glass Ionomer Cements which has fluoride releasing capacity, offers good bond strength and is esthetic have been long looked for. Aim: This study aimed to compare the clinical performance of GIC and Cention N in proximal restorations of primary molars. Materials and Methodology: A prospective study was conducted on 154 primary molars in patients aged between 5 and 8 years using a split-mouth design. Patients were divided into two groups. Control group restored with GIC and study group received Cention N. Both groups were assessed at baseline 3, 6 and 9 months according to Ryge criteria and data was statistically analysed using Fisher's Exact. Results: Statistically significant difference was found between GIC and Cention N restorations for color match at baseline and color stability at 3 months (P < 0.001), while the other parameters did not show any significant difference among the two restorative materials. Conclusion: Cention N can be used as a suitable alternative to GIC for restoring Class II restorations in primary molars.

Clinical assessment of occlusion and temporomandibular joint after placement of preformed metal crowns for primary molars / 口腔疾病防治

Objective @#To explore the effect on children's occlusion and temporomandibular joint (TMJ) after placement of preformed metal crowns and provide a reference for the restoration of defective primary molars. @*Methods @#A total of 39 children who underwent all primary molar metal crown restorations under general anesthesia were enrolled. The participants underwent occlusal contact area, percentage of total occlusal force, asymmetric ratio of occlusal force and occlusal contact time examinations with the T-scan computerized occlusal analysis system. Vertical dimension of occlusion (VDO) was measured using a dental vertical dimension gauge. TMJ dysfunction signs were recorded using the modified clinical dysfunction index (Di), and TMJ dysfunction symptoms were recorded using questionnaires. All data were collected at pretreatment, 1-week, 1-month, 3-month, and 6-month follow-up visits. @*Results@#The occlusal contact area at the 3-month and 6-month follow-up visits returned to the occlusal contact area of pretreatment, and the difference was statistically significant (P>0.05). Compared with pretreatment, the percentage of total occlusal force at the 3-month and 6-month follow-up visits increased significantly, and the difference was statistically significant (P<0.05). The asymmetric ratio of occlusal force and the occlusal contact time were significantly decreased at the 6-month follow-up visit (P<0.05). The vertical dimension of occlusion recovered after one month of treatment (P>0.05). The final statistical analysis of the TMJ assessment showed that there was no significant difference in the clinical disorder index and TMJ dysfunction symptoms before and after treatment (P>0.05). @*Conclusions @# After undergoing all primary molar metal crown restorations, occlusal re-equilibrations were attained after approximately one month. The percentage of total occlusal force and occlusal stability were significantly increased after six months of treatment, without significant temporomandibular joint dysfunction.

Comparative evaluation of diode laser and simvastatin gel in pulpotomy of primary molars A randomized clinical trial

Background: Pulpotomy is a vital pulp therapy performed in carious pulp exposures in teeth in which the inflamed coronal pulp is removed and medicament is placed to conserve the vital root pulps. Recently, simvastatin which is a cholesterol-lowering drug has been found to be associated with the pulp regenerative potential. Aim: The aim of this parallel two-arm randomized control trial was to evaluate and compare the clinical and radiographic efficacy of diode laser (DL) and simvastatin gel (SG) in pulpotomy of carious primary molars. Methods: Hundred primary molars (in 98 children, 65 males, 33 females with age 4–8 years) requiring pulpotomy were randomized into the DL or SG group. Pulpotomy was performed as per the standardized protocol; thereafter, all teeth were restored with resin modified glass ionomer cement followed by stainless steel crowns. Follow-up evaluations were done at 3 and 12 months using clinical and radiographic criteria. Statistical analysis was done using Chi-square test at a significance level of 0.05. Results: At 12 months, out of 92 teeth available for clinical and radiographic evaluation by blinded evaluators, DL group showed clinical and radiographic success rates of 76.1% and 52.1%, while SG group showed 80.4% and 65.2% success rates, respectively. There was no statistically significant difference between the efficacy of two techniques clinically (P = 0.49) or radiographically (P = 0.30). Conclusions: Both SG and DL had similar efficacy for primary tooth pulpotomy, clinically and radiographically after 12 months. Considering its ease of application and low-cost, SG can be recommended as a potential pulpotomy medicament in primary molars.

Prevalencia de infraoclusión en molares primarios de niños de 7 y 8 años, Valdivia, Chile, 2019 / Prevalência de infraoclusão em molares decíduos de crianças de 7 e 8 anos, Valdivia, Chile, 2019 / Prevalence of infraocclusion in primary molars of children 7 and 8 years old, Valdivia, Chile, 2019

Objetivo: Determinar la prevalencia de infraoclusión en molares primarios de niños de 7 y 8 años, Valdivia, Chile. Materiales y métodos: Estudio descriptivo de corte transversal. Se examinaron niños de 7 y 8 años en establecimientos educacionales de Valdivia. Fue evaluada la presencia y severidad de infraoclusión en molares primarios utilizando la clasificación de Brearley & McKibben. Para establecer diferencias estadísticas entre sexo y presencia de infraoclusión fue realizada la prueba de chi-cuadrado. Además un análisis de ANOVA fue utilizado para establecer diferencias entre la localización de la infraoclusión y el grado de severidad. El nivel de significancia estadística se estableció con un valor de p<0,05. Resultados: Fueron evaluados 359 niños y un 41,78% presentó infraoclusión. Según grado de severidad, 82,06% fueron leves, 15,28% moderadas y 2,66% severas. No se encontraron diferencias significativas entre sexo y presencia de infraoclusión. Se evidenciaron diferencias estadísticamente significativas al evaluar localización y grado de severidad (p<0,05). Conclusión: Existe una alta prevalencia de infraoclusión en niños de 7 y 8 años en Valdivia, Chile.

Objective: To determine the prevalence of infraocclusion in primary molars of children aged 7 and 8 in Valdivia, Chile. Materials and methods: Descriptive cross-sectional study. Children aged 7 and 8 were examined in educational institutions in Valdivia. The presence and severity of infraocclusion in primary molars was evaluated using the Brearley & McKibben classification. The chisquare test was performed to establish statistical differences between sex and presence of infraocclusion. In addition, an ANOVA test was used to establish differences between infraocclusion location and degree of severity. The level of statistical significance was established at p <0.05. Results: Of 359 children evaluated, 41.78% had infraocclusion. As per degree of severity, 82.06% of cases were mild, 15.28% moderate and 2.66% severe. No significant differences were found between sex and presence of infraocclusion. Statistically significant differences appeared when assessing location and degree of severity (p <0.05). Conclusion: There is a high prevalence of infraocclusion in children aged 7 and 8 in Valdivia, Chile

Objetivo: Determinar a prevalência de infraoclusão em molares decíduos de crianças de 7 e 8 anos, Valdivia, Chile. Materiais e métodos: Estudo transversal descritivo. Crianças de 7 e 8 anos foram examinadas em estabelecimentos de ensino em Valdivia. A presença e gravidade da infraoclusão em molares decíduos foram avaliadas pela classificação de Brearley & McKibben. Para estabelecer diferenças estatísticas entre sexo e presença de infraoclusão, foi realizado o teste do qui-quadrado. Além disso, uma análise ANOVA foi usada para estabelecer diferenças entre a localização da infra-oclusão e o grau de gravidade. O nível de significância estatística foi estabelecido com um valor de p <0,05. Resultados: 359 crianças foram avaliadas e 41,78% apresentaram infra-oclusão. De acordo com o grau de gravidade, 82,06% eram leves, 15,28% moderados e 2,66% graves. Não foram encontradas diferenças significativas entre sexo e presença de infra-oclusão. Diferenças estatisticamente significantes foram evidenciadas na avaliação da localização e do grau de gravidade (p <0,05). Conclusão: Existe uma alta prevalência de infra-oclusão em crianças de 7 e 8 anos em Valdivia, Chile

Kedo file system for root canal preparation in primary teeth

Endodontic instruments play a vital role during root canal preparation. Biomechanical preparation in primary teeth is performed using the adult endodontic files. There are various disadvantages during use of adult endodontic files in primary teeth namely the length and taper of the files. Recently, an exclusive paediatric endodontic file system has been introduced for cleaning and shaping of primary root canals. This short communication describes the use of exclusive Kedo-SH manual and Kedo-S rotary file system in primary teeth.

The Use of Micro-Computed Tomography for Evaluation of Internal Adaptation of Dental Restorative Materials in Primary Molars: An In-Vitro Study

Aim: To evaluate the internal adaptation of some dental adhesive restorative material (Nano-composite resin /Biodentine,Nanocomposite resin / Nano- resin-modified glass ionomer and Nano-composite resin) to the primary dentinal surface usingmicro-computed tomography (Micro-CT) Materials and methods: Forty-five extracted primary molars, due to caries ororthodontic reasons, were collected provided that it has an intact buccal/ lingual surface(s) and one half to two-thirds ofroot length. The selected teeth were disinfected and stored in normal saline at room temperature. The teeth were randomlyassigned to one of the three experimental restorative groups according to the restoration type (15 per group): group A:Nanocomposite resin / Biodentine, group B: Nanocomposite resin / Nano-resin-modified glass ionomer and group C:restored totally with Nanocomposite resin. A high- resolution desktop micro-CT (Model 1172, Skyscan, Belgium) was usedto image the samples. Results: The mean rank of volumetric dimension values of the total gap at the restorative material –dentine interface demonstrated significant difference among the three groups (P= 0.003). Moreover, there was a significantdifference in the mean rank of the ratio of total gap volume/cavity volume among the three restorative groups (P=0.015).The data demonstrate that group A showed the lowest in total gap volume and mean ratio of total gap volume /cavity volumewhile group C recorded the highest value. Conclusion: Biodentine exhibited a higher internal adaptation to a dentinalsurface which is comparable to Nano resin-modified glass ionomer. The study results potentiate the importance of usingBiodentine liners under Nano-composite (sandwich technique) in terms of excellent internal adaptation, in addition to itshigh biocompatibility and easy handling as well.

A Study of Root Canals Morphology in Primary Molars using Computerized Tomography / 대한소아치과학회지

The purpose of this study is to identify the most common canal type in primary molars and the correlation between their roots and canals. A comprehensive understanding of root canal morphology will lead to more successful root canal treatment.Computed Tomography (CT) images from 114 children (81 boys, 33 girls) aged 3 - 7 years were obtained. The locations and numbers of roots and canals were evaluated, and the relationship between root and canal parameters was determined.The most commonly observed canal morphology in primary maxillary molars were mesio-buccal, disto-buccal and palatal canal. Primary mandibular molars most frequently contain mesio-buccal, mesio-lingual, disto-buccal and distolingual canal. All the roots of the primary maxillary molars except for the mesio-buccal root, each had 1 canal while there were 2 canals observed in each root of primary mandibular molars. Without exception, all mesial roots in primary mandibular 2nd molars had 2 canals. In case when either the palatal root in a primary maxillary molar or the distal root in a primary mandibular molar was separated into 2 roots, each root seemed to have its own canal. Even though the disto-buccal and palatal roots were fused into 1 root in primary maxillary molars, this fused root had tendency to have 2 separate canals. Primary mandibular molars showed similar canal morphologies between left and right molars in the same patient, while the primary maxillary molars did not.

Clinical and Radiographic evaluation of mixture of Zinc Oxide powder and Nanohydroxyapatite as an obturating material in primary molars / Avaliação clínica e radiográfica da associação do pó de óxido de zinco com nanohidroxiapatita como um material obturador utilizado em primeiros molares

Pulpectomy is the treatment alternative in rescuing the pulpally involved carious primary teeth. Various obturating materials are being used to conserve an infected deciduous dentition. The present study documents the use of a novel obturating material in primary molars due to the disadvantages associated with of the currently used materials. Objective: To evaluate clinically and radiographically the success rate of the mixture of zinc oxide powder and nanohydroxyapatite with saline as an obturating material in primary molars and also to compare its efficiency with Endoflas. Material and Methods: Thirty pulpectomy indicated primary molars were randomly divided into two equal groups; Group I (mixture of zinc oxide powder and nanohydroxyapatite with saline) and Group II (Endoflas FS). The teeth were evaluated using various clinical and radiographic criteria at 3, 6 and 9-month intervals. The obtained results were statistically analyzed (P <0.05). Results: The overall present study findings revealed 100% clinical success in both the groups. Whereas radiographically, success reported was 66% for Group I and 100% for Group II at the end of 9 months followup. The difference in the radiographic success rate between the two groups was statistically significant (P <0.05). Conclusion: Endoflas FS had demonstrated high success rate both clinically and radiographically when compared to the novel combination of a mixture of zinc oxide powder and nanohydroxyapatite with saline as obturating material. (AU)

Pulpectomia é uma alternativa de tratamento que visa resgatar polpas envolvidas em processos cariosos de dentes decíduos. Vários materiais obturadores estão sendo usados para conservar a dentição decídua infectada. O presente estudo relata o uso de um novo material obturador em molares decíduos devido às desvantagens dos materiais atualmente utilizados. Objectivo: Avaliar clínica e radiograficamente a taxa de sucesso da mistura de pó de óxido de zinco e nanoidroxiapatita como material obturador em molares decíduos e também comparar sua eficiência com Endoflash. Material e Métodos: Trinta molares decíduos que foram indicados para pulpectomias foram divididos aleatoriamente em dois grupos iguais; Grupo I (mistura de pó de óxido de zinco e nanoidroxiapatita) e Grupo II (Endoflash). Os dentes foram avaliados utilizando vários critérios clínicos e radiográficos em intervalos de 3, 6 e 9 meses. Os resultados obtidos foram analisados estatisticamente (P <0,05). Resultados: Os achados gerais do presente estudo revelaram sucesso clínico de 100% em ambos os grupos. Enquanto que radiograficamente, o sucesso relatado foi de 66% para o Grupo I e 100% para o Grupo II ao final de 9 meses de acompanhamento. A diferença na taxa de sucesso radiográfico entre os dois grupos foi estatisticamente significante (P <0,05). Conclusão: O Endoflas demonstrou alta taxa de sucesso tanto clínica como radiograficamente quando comparado à nova combinação de pó de óxido de zinco e nanoidroxiapatita como material obturador (AU)

Effect of protective coating on microleakage of conventional glass ionomer cement and resin-modified glass ionomer cement in primary molars: An In vitro study

The aim of this in vitro study was to evaluate and compare the effect of protective coating G-Coat Plus on microleakage of conventional glass ionomer cement (CGIC) and resin-modified glass ionomer cement (RMGIC) in primary molars. Materials and Methods: A total of 120 samples were divided into four groups with 30 samples in each group. Group A – teeth restored with CGIC. Group B – teeth restored with CGIC coated with G-Coat Plus. Group C – teeth restored with RMGIC. Group D – teeth restored with RMGIC coated with G-Coat Plus. Microleakage was tested using 2% basic fuschin dye penetration and measured at ×40 original magnification under the stereomicroscope. Results: The results of this in vitro study showed that coating with G-Coat Plus showed a reduction in microleakage in CGIC and complete absence of microleakage in RMGIC when compared to the noncoated groups, which was statistically significant. CGIC without G-Coat Plus showed highest microleakage followed by RMGIC without G-Coat Plus, followed by a relatively less microleakage in CGIC with G-Coat Plus. Conclusion: Significant reduction in microleakage was seen in conventional GIC and RMGIC with G-Coat Plus when compared to conventional GIC and RMGIC without G-Coat Plus.

Evaluation of Microtensile Bond Strength of Sealant Depending on the Duration of Etching and the Use of Bonding Agent / 대한소아치과학회지

The aim of this study was to evaluate the effect of etching time and bonding agents on bond strength of sealant applied to the occlusal surface of primary molars.Forty non-carious exfoliated human primary molars were included in the study. The teeth were randomly divided into 4 groups for measurement. For group I, no acid etching treatment was used. For group II, III, and IV, acid etching gels were applied on the occlusal surface for 15, 30, and 60 seconds, respectively. Each group was divided into 2 subgroups; one group was treated with bonding agents on the enamel while the other was not. Microtensile bond strength was evaluated using a universal testing machine.There were no statistically significant differences in bond strength with varying duration of etching among groups. The results revealed that the use of bonding agents prior to application of fissure sealant increased the bond strength(p < 0.05).It could be concluded that etching time greater than 15 seconds does not significantly enhance the bond strength, but the use of bonding agents as an intermediate layer between the primary molar and fissure sealant would be beneficial in increasing the bond strength.

Clinical study of root canal numbers in maxillary second primary molars / 口腔疾病防治

Objective@#To investigate the root canal numbers of maxillary second primary molars.@*Methods @#216 max illary second primary molars from 204 children aged 3-8 years old were selected. All the teeth need to do the root canal therapy. After opening the pulp chamber, the root canal were examined and determined with small size K file and 17％ethylene diaminetetraacetic acid (EDTA). Hand instruments were used for root canal preparation and then zinc-oxide iodoform paste was used for filling. @*Results @#216 maxillary second p rimary molars, 122 teeth had three root canals(56.5%), and 94 teeth had four root canals (43.5%). The incidence of second mesiobuccal canal (MB2) was 41.2%. There was no correlation between the incidence of the MB2 canal and gender and tooth position. @*Conclusion@# The root canals of maxillary second primary molars had more variations, and there was a high incidence of the second mesiobuccal canal.

Clinical study of the second mesiobuccal canal of maxillary second primary molars / 实用口腔医学杂志

The root canals of 95 maxillary second primary molars were explored by 10#file combined with 17%EDTA.The canal orifice was observed and orientated by endoscope.Hand instruments were used for root canal preparation and screw conveyor was used to fill the ca-nal with Vitapex paste.MB2 was found in 14 of the 95 molars(14.7%).MB2 orifice was usually located mesially along MB-P.

Risk factors for dental caries incidence in children's permanent teeth: four-year follow-up study / 대한구강보건학회지

OBJECTIVES: The aim of this study was to analyze the related factors to dental caries incidence and increments of DMFT index in children's permanent teeth. METHODS: The subjects were 249 elementary school children at the baseline survey. At the four-year follow-up survey, number of subjects reduced to 141. In the first year, all subjects submitted the responses of questionnaire composed of demographic variables and oral health behaviors. They also received oral examination and tests of salivary excretion rate, salivary buffer capacity, Dentocult(R) SM and Dentocult(R) LB. In the first to fourth follow-up year, they received oral examinations. The relation of oral health-related factors with caries incidence and increments of DMFT and DMFS index was analyzed by chi-square test, ANOVA, logistic regression analysis and generalized linear model analysis using Poisson distribution. RESULTS: At four-year follow-up survey, subjects whose Dentocult(R) SM was 2 or higher compared to subjects whose Dentocult(R) SM was 1 or less and subjects whose Dentocult(R) LB was 2 or higher compared to subjects whose Dentocult(R) LB was 1 or less had higher DMFT index increments. In DMFT index increments, the adjusted odds ratio of subjects whose dfs index of primary molars was 11 and more was 4.30 compared to subjects whose dfs index of primary molars was 0 adjusted for gender, daily frequency of toothbrushing and eating between meal, mother's job, oral health education, salivary excretion, salivary buffer capacity and Dentocult(R) SM test. CONCLUSIONS: It was suggested that the caries incidence and increments of DMFT index in permanent teeth should be highly associated with salivary lactobacillus count and dfs index of primary molars.

Uso de restaurações indiretas na correção da infra-oclusão: relato de caso / Use of indirect restorative technique for the correction of retained primary molar: case report

A infraoclusão de molares decíduos é uma situação clínica que pode causar prejuízos ao desenvolvimento da oclusão do paciente, mas com o desenvolvimento das técnicas e materiais odontológicos nos últimos anos, esse quadro clínico pode ser solucionado através de uma terapia mais conservadora. Este trabalho tem como objetivo apresentar a reabilitação de um dente em infraoclusão através da utilização de uma restauração indireta em resina composta. Esta técnica permite restabelecer as dimensões anatômicas, o equilíbrio oclusal e a estética da criança. Ao final pôde-se concluir que as restaurações indiretas em resina são uma boa opção de tratamento conservador para os casos de infraoclusão na dentição decídua.

Infraoccluded primary molars is a common clinical situation that can cause several damages for the development of occlusion, but with today?s development of the techniques and dental materials these clinical situation has several ways to be resolved, returning the oclusal balance for the patient. This article had as aim present a clinical report of a rehabilitation of an infraoccluded primary molar with the use of an indirect restoration in composite resin, designed to restore the anatomical size, the occlusion and esthetics of the child. At the end we can conclude that this technique presents several advantages, especially in Pediatric Dentistry.

Efeito do Bisel no Esmalte Sobre a Microinfiltração em Preparos Classe I em Molares Decíduos / Effect of Enamel Bevel on Microleakage in Class I Cavities in Primary Molars

Objetivo: Avaliar in vitro a influência da terminação marginal do preparo cavitário Classe I sobre a qualidade adesiva em restaurações compósitas realizadas em primeiros e segundos molares decíduos.Método: Dois preparos cavitários foram realizados na oclusal de vinte molares decíduos hígidos, sendo 20 preparos em primeiros molares e 20 em segundos molares, totalizando quarenta preparos cavitários. Após escolha aleatória, 20 preparos não receberam o bisel reto (grupo controle, GI, n=20) enquanto os demais preparos, grupo experimental, (GII, n=20) receberam um bisel reto com 0,5 mm de extensão no ângulo cavo û superficial feito com ponta diamantada ultra-fina 2200 FF. Para o procedimento restaurador, utilizou-se condicionamento ácido total com ácido fosfórico a 37% por 30s, sistema adesivo Prime & Bond NT® e compósito TPH® Spectrum cor A2. Para avaliação da qualidade adesiva, os dentes foram isolados com verniz, exceto às restaurações e 1,0 mm além das suas margens, e permaneceram em contato direto com uma solução aquosa de nitrato de prata a 50%, por 24 h. Em seguida, estes dentes foram clivados mesiodistalmente, e as restaurações avaliadas com 40 vezes de aumento. Dois avaliadores calibrados classificaram independentemente as restaurações de acordo com escores que variaram de zero (ausência de microinfiltração) a três (máxima microinfiltração). Os dados foram analisados descritivamente e tratados com os testes de Wilcoxon, Qui-quadrado e exato de Fisher a um nível de confiança de 95%.Resultados: O GII mostrou maiores escores de microinfiltração que o GI (p<0.001; p=0.0001). Os primeiros molares decíduos sofreram mais microinfiltração na presença de bisel (p=0.0003). Conclusão: O bisel no ângulo cavo-superficial em preparos Classe I aumentou a infiltração marginal nas restaurações compósitas em molares decíduos, principalmente nos primeiros molares

Objective: To evaluate in vitro the influence of Class I cavity marginal preparation on the adhesive quality in composite resin restorations placed in first and second primary molars.Method: Two cavities were prepared on the oclusal face of twenty sound primary molars, being twenty cavities in first molars and twenty in second molars, totalizing forty cavities. After random allocation, twenty cavities did not receive a straight bevel (control group, GI, n=20) while in the other cavities (experimental group, GII, n=20) a 0.5 mm straight bevel was made in the cavosurface angle with ultra-fine diamond bur 2200 FF. The restorative procedure included 37% phosphoric acid etching for 30 s, application of Prime & Bond NT®adhesive system and placement of TPH®Spectrum composite resin (shade A2). For evaluation of the adhesive quality, the teeth were coated with varnish, except for the restorations and a 1.0-mm-wide window beyond its margins, and were immersed in a 50% silver nitrate aqueous solution for 24 h. Next, the teeth were cleaved mesiodistally and the restorations were examined at ×40 magnification. Two independent calibrated examiners classified the restorations according to scores from zero (absence of microleakage) to three (maximum microleakage). Data were analyzed descriptively and treated with Wilcoxon, Chi-Square and FisherÆs exact tests at a confidence level of 95%.Results: GII presented higher microleakage scores than GI (p<0.001; p=0.0001). The primary first molars showed greater microleakage in the presence of bevel (p=0.0003). Conclusion: Beveling the cavosurface angle in Class I cavities increased marginal microleakage in the composite resin restorations placed in primary molars, especially in the first molars

Endodontic treatment in primary molars with taurodontism.

Dental morphological traits are of particular importance in the study of phylogenetic relationships and population affinities. One of the most important abnormalities in tooth morphology is Taurodontism. Taurodontism can be defined as a change in tooth shape caused by the failure of Hertwig’s epithelial sheath diaphragm to invaginate at the proper horizontal level. An enlarged pulp chamber, apical displacement of the pulpal floor, and no constriction at the level of the cementoenamel junction are the characteristic features. Although permanent molar teeth are most commonly affected, this change is very rarely seen in primary dentition. Taurodontism has a very low incidence in primary dentition and very few cases have been reported in the literature. Endodontic treatment of a taurodont tooth is challenging, because it requires special care in handling and identifying the canal obliteration and configuration and the potential for additional root canal systems. This paper highlights a case report of taurodontism in primary molars of a five year old male child with endodontic treatment.

Comparative analysis of the eletronic and radiographic determination of root canal length of primary molars: an ex vivo study

Aim: To evaluate comparatively the radiographic and electronic root canal length determination in primary molars. Methods: 128 canals from 66 primary molars were selected. The root of each tooth was cut open on the occlusal face, and the real tooth length (RTL) was measured and the gold standard working length (WL) was determined by subtracting 1 mm from this measurement. The teeth were then placed in a plastic receptacle holding alginate and saline for the electronic determination of the root length using a Root ZX apex locator. The radiographic determination of the WL was obtained by subtracting 1 mm from the measurement highest cusp to the root apex appearing in the radiography. The data were analyzed statistically by the Chi-square test at a 5% significance level. Results: There was statistically significant difference (p<0.05) between each tested method and the gold standard. The Root ZX apex locator and the radiographic method presented satisfactory results in 75.78% and 54.68% of the cases, respectively. Conclusions: The Root ZX apex locator is a reliable method to determine the WL of primary teeth, since it showed greater accuracy than the radiographic method.