RESUMO
This study evaluated the association between single-nucleotide polymorphisms (SNPs) in vitamin-D-related genes and the amount of external apical root resorption linked to orthodontic treatment. One hundred and forty-three individuals were assessed. The amount of external apical root resorption of upper central incisors (EARRinc ) and lower first molars (EARRmol ) were evaluated in radiographs. Seven SNPs were genotyped across four genes including the vitamin D receptor [VDR], group-specific component [GC], cytochrome P450 family 27 subfamily B member 1 [CYP27B1], and cytochrome P450 family 24 subfamily A member 1 [CYP24A1]. Linear regressions were implemented to determine allele-effects on external apical root resorption. Individuals carrying the AA genotype in VDR rs2228570 had a 21% higher EARRmol than those having AG and GG genotypes (95% CI: 1.03,1.40). EARRmol in heterozygous rs2228570, was 12% lower than for homozygotes (95%CI: 0.78,0.99). Participants with the CCG haplotype (rs1544410-rs7975232-rs731236) in VDR had an EARRmol 16% lower than those who did not carry this haplotype. Regarding CYP27B1 rs4646536, EARRinc in participants who had at least one G allele was 42% lower than for homozygotes AA (95%CI: 0.37,0.93). Although these results did not remain significant after multiple testing adjustment, potential associations may still be suggested. Further replication studies are needed to confirm or refute these findings.
Assuntos
Reabsorção da Raiz , Vitamina D , Humanos , 25-Hidroxivitamina D3 1-alfa-Hidroxilase/genética , Reabsorção da Raiz/diagnóstico por imagem , Reabsorção da Raiz/genética , Receptores de Calcitriol/genética , Genótipo , Vitaminas , Polimorfismo de Nucleotídeo Único , Predisposição Genética para Doença , Estudos de Casos e ControlesRESUMO
INTRODUCTION: Developmental Defects of Enamel (DDEs) comprise qualitative and/or quantitative changes to the enamel during amelogenesis. The aetiology of DDE remains inconclusive. AIM: To determine the association of pre, peri, and postnatal factors with the presence of DDE. DESIGN: Cross-sectional study with 353 children (8 to 11 years-old) in a Brazilian town. METHODS: One calibrated dentist assessed DDE using the Developmental Defects of Enamel Index and a questionnaire collected medical and sociodemographic data. MAIN OUTCOMES: Children with at least one type of DDE were categorized into the DDE group. Subtypes of DDE were also recorded. RESULTS: 63.1% of children had at least one type of DDE. Diffuse opacity was present in 36.7%, demarcated opacity in 14.8%, and hypoplasia in 5.83% of the children. In multivariate analysis, demarcated opacities and hypoplasia were associated with birth weight ⟨ 2500g (OR = 4.82; 95% CI 1.23-1.95). CONCLUSION: Low birth weight predicted DDE.
Assuntos
Hipoplasia do Esmalte Dentário , Brasil/epidemiologia , Criança , Estudos Transversais , Esmalte Dentário , Hipoplasia do Esmalte Dentário/epidemiologia , Humanos , Prevalência , Fatores de RiscoRESUMO
AIM: To evaluate the effectiveness of five instruments used for irrigant agitation during the removal of calcium hydroxide [Ca(OH)2 ] paste in simulated internal root resorption (IRR) cavities created in extracted maxillary central incisors. METHODOLOGY: Seventy maxillary central incisors with a single canal were selected. The canals were accessed and instrumented with Reciproc R50, then the roots were split in the bucco-lingual direction and the halves separated. Simulated IRR cavities were created, in both halves of the roots, 5 mm from the apex with a spherical bur. The specimens were reconstructed with cyanoacrylate glue and allocated into seven groups: negative control - no treatment; positive control - filled with Ca(OH)2 without performing any irrigation protocol; the other groups were divided according to the instrument used for irrigant agitation, namely: Ultrasonic, EndoActivator® , EDDY® , XP-endo® Finisher and XP-endo® Shaper. The specimens were cleaved and analysed using optical microscopy and scanning electron microscopy, to compare the Ca(OH)2 remnants between them. Then, the IRR cavities created by the burs were cleaned and subjected to a protocol of demineralization with 20% nitric acid, the roots reconstructed, and the irrigant agitation methods, as well as the microscopic analysis was repeated. Analysis of the images of Ca(OH)2 remaining in the simulated IRR cavities after irrigation was performed by two calibrated examiners based on a previously established scoring system. The data were statistically compared by Kruskal-Wallis test, Mann-Whitney U-test and Wilcoxon tests, with the significance level set at 5%. RESULTS: There was a significant difference in the effectiveness of the instruments in relation to the cavity creation method (bur vs. bur/acid) and evaluation method (optical microscopy and scanning electron microscopy) (P < 0.05). The XP-endo® Finisher and EDDY® groups were associated with significantly more effective removal of Ca(OH)2 when the IRR cavities were created using the acid protocol and analysed by scanning electron microscopy. CONCLUSION: None of the instruments tested were able to completely remove the Ca(OH)2 paste from the simulated IRR cavities; however, the EDDY® and XP-endo® Finisher removed more Ca(OH)2 in the bur/acid cavity creation method analysed by scanning electron microscopy.
Assuntos
Cárie Dentária , Reabsorção da Raiz , Hidróxido de Cálcio , Cavidade Pulpar , Humanos , Incisivo , Irrigantes do Canal Radicular , Preparo de Canal Radicular , Irrigação TerapêuticaRESUMO
AIM: To assess the efficacy of different retreatment rotary files in removing gutta-percha and endodontic sealer from canals. METHODOLOGY: Ninety straight single-rooted premolars were prepared up to a size 30 and filled with gutta-percha and sealer and then randomly assigned to six retreatment groups (n = 15). Groups I, III, and V were retreated using rotary systems ProTaper Universal Retreatment (PTUR), D-RaCe, and Mtwo Retreatment, respectively. Groups II, IV, and VI were retreated using the additional instruments F4, size 40, .04 taper RaCe, and size 40, .04 taper Mtwo, respectively. The roots were split vertically, and images of the halves were obtained using a high-resolution scanner and evaluated with AutoCAD software to calculate the percentage of residual material. Data were analyzed with Kruskal-Wallis and Student-Newman-Keuls tests using a 5% significance cutoff (P < 0.05). RESULTS: There were no statistically significant differences (P > 0.05) between groups when additional instruments were used. The percentage of residual material was lowest in the PTUR group and was statistically significant only when compared to the D-RaCe system (P = 0.0038). CONCLUSIONS: All root canals had residual filling material after retreatment even when additional instruments were used.
Assuntos
Instrumentos Odontológicos , Materiais Restauradores do Canal Radicular , Tratamento do Canal Radicular/instrumentação , Dente Pré-Molar , Guta-Percha , Humanos , Níquel , Retratamento/instrumentação , Estatísticas não Paramétricas , TitânioRESUMO
AIM: To report an anatomical variation in maxillary first molars. SUMMARY: A case report is presented of a maxillary first molar requiring root-canal treatment that had two palatal roots with distinct canals and foramena at the apical level. Root-canal treatment was performed using mechanical instrumentation with NiTi files. An anatomical study on two extracted maxillary second molars with the same variation revealed their internal structure. This case demonstrates an uncommon anatomical condition and supplements previous reports of such cases affecting maxillary molars. KEY LEARNING POINTS: Clinicians should be aware of uncommon anatomical variations in maxillary molars. The majority of maxillary first molars have three roots and four canals. Maxillary molars may have two canals in the palatal root.
Assuntos
Cavidade Pulpar/patologia , Dente Molar/patologia , Preparo de Canal Radicular/métodos , Raiz Dentária/patologia , Adulto , Ligas Dentárias , Feminino , Humanos , Maxila , Níquel , Obturação do Canal Radicular/métodos , Preparo de Canal Radicular/instrumentação , Titânio , Ápice Dentário/patologiaRESUMO
AIM: The objective of this study was to determine the effectiveness of 0.04 ProFile instruments during the removal of root fillings. METHODOLOGY: A total of 30 single-rooted mandibular canines were divided into three groups. The canals were accessed and then prepared with a reciprocating automated device and nickel-titanium files. Three different techniques of obturation were used: Thermafil system (group I), thermomechanical compaction (group II) and lateral condensation (group III). Sealer 26 was used in all three groups. Two weeks after obturation, the fillings were removed using 0.04 ProFile instruments following standardized sequence of size 90, 60, 45, 40, 35 and 30 at a speed of 300 rpm in a crown-down manner. The teeth were subsequently split with a chisel, photographs were taken with a colour video camera and the removal of filling material was assessed visually (by colour) by two examiners. The time required to achieve the working length was also recorded. RESULTS: ProFile instruments reached the working length in all cases. However, complete removal of gutta-percha occurred in only three specimens (two of group I, and one of group II). Thermafil plastic carriers were removed successfully in all specimens of group I. CONCLUSIONS: ProFile instruments with 0.04 taper were inadequate in completely removing the filling materials from the root canal system. However, the ideal working length was achieved rapidly.
Assuntos
Instrumentos Odontológicos , Preparo de Canal Radicular/instrumentação , Dente Canino , Ligas Dentárias , Guta-Percha , Humanos , Níquel , Retratamento , Obturação do Canal Radicular , TitânioRESUMO
With the development of rotary nickel-titanium files and their applications in Endodontics, the concepts of root canal preparation have changed. The objective of this research is to evaluate the transportation of simulated root canals caused by stainless steel ENDOflash rotary files compared to nickel-titanium ProFile files (.04, .06 and Orifice Shapers). Twenty-four simulated root canals with a 30 degrees curvature were randomly divided into 2 groups and prepared with ENDOflash or ProFile files according to manufacturers' instructions. Comparison between the simulated root canals before and after instrumentation showed significant differences (p < 0.001) between the groups, with greater transportation observed with ENDOflash files. One case of deformation was observed with a ProFile instrument (#20/.04) and there were no fractures.