Crown Fracture of an Unerupted Incisor in a Young Child: Case Report and Restorative Protocol.

Aim: This case report describes a protocol for restoring a crown fracture of an unerupted permanent incisor in a child. Background: Crown fractures are an important concern in pediatric dentistry due to the negative impact on oral health-related quality of life (OHRQoL) in children and adolescents resulting from functional limitations as well as consequences related to social and emotional well-being. Case description: An enamel and dentin fracture of the crown of unerupted tooth 11 due to direct trauma is being presented in a 7-year-old girl. The restorative treatment involved minimally invasive dentistry, including computer-aided design (CAD)/computer-aided manufacturing (CAM) technology and direct resin restoration. Conclusion: The treatment decision was essential for maintaining pulp vitality and continued root development, as well as ensuring esthetic and functional results. Clinical significance: Crown fracture of an unerupted incisor may occur in childhood, requiring a long-term clinical and radiographic follow-up. Predictable, positive, and reliable esthetic outcomes can be achieved using CAD/CAM technology combined with adhesive protocols. How to cite this article: Kamanski D, Tavares JG, Weber JBB, et al. Crown Fracture of an Unerupted Incisor in a Young Child: Case Report and Restorative Protocol. Int J Clin Pediatr Dent 2022;15(5):636-641.

Effect of preheating on cytotoxicity and physicochemical properties of light-cured calcium-based cements.

The aim of this study was to evaluate the degree of conversion, cytotoxicity, solubility and pH of photopolymerizable calciumbased cements submitted to preheating. The degree of conversion was analyzed by Fourier transform infrared, cytotoxicity by the MTT test and solubility through loss of mass. The data were subjected to statistical tests (ANOVA / Tukey's, p<0.05). The photopolymerizable materials showed a low degree of conversion, regardless of preheating. All materials caused a reduction in cell viability at 24 hours and 7 days, with the Dycal (control) being more cytotoxic. Heat had a positive effect on Biocal at 7 days. Dycal is the most soluble material. Heat had no effect on the solubility or pH of the polymerizable materials. It is concluded that photopolymerizable calcium-based cements have a low degree of conversion and are soluble, which results in mild to moderate cytotoxicity.

O objetivo do presente estudo foi avaliar o grau de conversão, citotoxicidade, solubilidade e pH de cimentos à base de cálcio fotopolimerizáveis submetidos a pré-aquecimento. O grau de conversão foi analisado por espectroscopia no infravermelho com transformada de Fourier, a citotoxicidade pelo teste de MTT e a solubilidade através da perda de massa. Os dados foram submetidos a testes estatísticos (ANOVA/Tukey, p<0,05). Os materiais fotopolimerizáveis apresentaram baixo grau de conversão, independente do pré-aquecimento. Todos os materiais causaram redução da viabilidade celular nas análises de 24 horas e 7 dias, sendo que o Dycal (controle) apresentouse mais citotóxico e o calor apresentou efeito positivo sobre o Biocal na análise de 7 dias. O Dycal é o material mais solúvel e o calor não causou efeito na solubilidade e pH dos materiais polimerizáveis. Assim, conclui-se que os cimentos à base de cálcio fotopolimerizáveis apresentam baixo grau de conversão e são solúveis, que resulta em citotoxicidade suave e moderada.

Effect of preheating on cytotoxicity and physicochemical properties of light-cured calcium-based cements / Efeito do pré-aquecimento na citotoxicidade e propriedades físico-químicas de cimentos à base de cálcio fotopolimerizáveis

ABSTRACT The aim of this study was to evaluate the degree of conversion, cytotoxicity, solubility and pH of photopolymerizable calciumbased cements submitted to preheating. The degree of conversion was analyzed by Fourier transform infrared, cytotoxicity by the MTT test and solubility through loss of mass. The data were subjected to statistical tests (ANOVA / Tukey's, p<0.05). The photopolymerizable materials showed a low degree of conversion, regardless of preheating. All materials caused a reduction in cell viability at 24 hours and 7 days, with the Dycal (control) being more cytotoxic. Heat had a positive effect on Biocal at 7 days. Dycal is the most soluble material. Heat had no effect on the solubility or pH of the polymerizable materials. It is concluded that photopolymerizable calcium-based cements have a low degree of conversion and are soluble, which results in mild to moderate cytotoxicity.

RESUMO O objetivo do presente estudo foi avaliar o grau de conversão, citotoxicidade, solubilidade e pH de cimentos à base de cálcio fotopolimerizáveis submetidos a pré-aquecimento. O grau de conversão foi analisado por espectroscopia no infravermelho com transformada de Fourier, a citotoxicidade pelo teste de MTT e a solubilidade através da perda de massa. Os dados foram submetidos a testes estatísticos (ANOVA/Tukey, p<0,05). Os materiais fotopolimerizáveis apresentaram baixo grau de conversão, independente do pré-aquecimento. Todos os materiais causaram redução da viabilidade celular nas análises de 24 horas e 7 dias, sendo que o Dycal (controle) apresentouse mais citotóxico e o calor apresentou efeito positivo sobre o Biocal na análise de 7 dias. O Dycal é o material mais solúvel e o calor não causou efeito na solubilidade e pH dos materiais polimerizáveis. Assim, conclui-se que os cimentos à base de cálcio fotopolimerizáveis apresentam baixo grau de conversão e são solúveis, que resulta em citotoxicidade suave e moderada.

Mesiolingual Canal Prevalence in Maxillary First Molars assessed through Different Methods.

AIM: Evaluate the prevalence of mesiolingual canal prevalence orifice in mesiobuccal roots of maxillary first molars using five methods of visualization. MATERIALS AND METHODS: About 73 first permanent maxillary molars were analyzed. Visual clinical analysis of the presence of the fourth canal was performed using a straight end-odontic exploratory probe (EXDG16®) and a K10 manual file (SybronEndo®). Dental elements that were not located on the fourth canal were analyzed with the aid of a magnifying glass (Zeiss®) with a 2.5-fold increase and those teeth in which the fourth canal was not found went through the examination with clinical surgical microscope (OPTO®) with magnification of 20 times with both the explorer and endodontic file. Next, a periapical radiography of the teeth was performed in the teeth in which the mesiolingual canal was not yet found to observe the presence or absence of the fourth canal. Afterward, the teeth in which the canal was not yet located were scanned using the microtomography equipment (SkyScan®), at 100 kV and 100 µA, with an isotropic resolution of 16 µm. RESULTS: The mesiolingual canal was located in 70 teeth (95.8%) and in only 3 teeth it was not identified. CONCLUSION: The visual method in the fourth canal search has limitations, whereas the composite magnifying glass, the clinical surgical microscopy, and the computerized microtomography are efficient methods for locating the fourth canal in the upper first molars. CLINICAL SIGNIFICANCE: The anatomical complexity of the first maxillary molars is one of the factors that leads to high failure rates in the endodontic treatments of this group of teeth. In most clinical situations, the mesiolingual canal goes unnoticed by professionals, since conventional radiographs do not always allow the visualization of all root canals. Determining an effective method for locating the mesiolingual canal is of paramount importance to the success of endodontic treatment.

Effect of At-home and In-office Bleaching on Marginal Microleakage in Composite Resin Restorations using Two Adhesive Systems.

AIM: The aim of this study is to assess marginal microleakage of cervical cavities restored with composite resins and two different adhesive techniques subjected to at-home and in-office bleaching. MATERIALS AND METHODS: In this randomized, blind laboratory experiment, 60 bovine teeth recently extracted were collected and divided into six groups (n = 10 each group). The teeth received cervical cavity preparations (2 mm × 3 mm × 1 mm) with enamel margins. Two different adhesive systems were used (Single Bond 2 and Clearfil SE Bond), in addition to composite resin (Z250). Restored teeth received two different bleaching gels (Opalescence PF and Opalescence Boost). Teeth were thermo-cycled and analyzed under confocal laser scanning microscopy. RESULTS: No significant differences were observed (p > 0.05) in microleakage scores between the two groups not subjected to bleaching nor between the four groups that received bleaching treatment (p > 0.05), regardless of the gel and adhesive system employed. However, when comparing nonbleached with bleached teeth, those not subjected to bleaching showed statistically lower marginal microleakage scores (p < 0.05). Data were statistically analyzed using the Kruskal-Wallis test followed by Student-Newman-Keuls post hoc test, with significance set at 5%. CONCLUSION: Marginal microleakage in composite resin restorations is influenced by the action of bleaching agents used both at-home and in-office, regardless of the adhesive system employed (total-etch or self-etch). CLINICAL SIGNIFICANCE: Both at-home and in-office bleaching agents have an influence on the adhesive interface of resin restorations, producing changes and inducing marginal leakage.

Minimally invasive intervention in a case of a noncarious lesion and severe loss of tooth structure.

The present article describes a minimally invasive technique used for the restoration of loss of tooth structure caused by erosion of intrinsic etiology. First, the cause of erosion was treated and controlled. Subsequently, taking into consideration patient characteristics, especially a young age, a more conservative technique was chosen for dental rehabilitation with the use of composite resin. The advantages and disadvantages of the technique employed are discussed.