Abstract This case report describes a favorable healing outcome of the immediate management of an oblique tooth root fracture in the middle third concomitant with coronal fragment extrusion in a permanent maxillary left central incisor of a healthy 14-year-old female patient. The clinical exam showed incisal irregularity, local bleeding, increased mobility, and axial displacement of the maxillary left central incisor. The coronal fragment was repositioned and stabilized with a flexible splint for four weeks. The parents and the patient received medication prescriptions and instructions. Clinical and radiographic conditions remained satisfactory at the 4-week, 6-month, and 12-month follow-ups. Thermal and percussion tests confirmed pulp vitality after 12 months. Hard tissue formation between segments was observed in the radiographic examination and cone-beam computed tomography. In conclusion, the immediate conservative therapeutic showed satisfactory clinical and radiographic results.

Resumo Este relato de caso descreve resultados de cicatrização favorável para o tratamento imediato de fratura dentária radicular oblíqua no terço médio concomitante à extrusão do fragmento coronal de um incisivo central superior esquerdo permanente de uma paciente saudável de 14 anos de idade. O exame clínico demonstrou irregularidade incisal, sangramento local, aumento da mobilidade e deslocamento axial do incisivo central superior esquerdo. O fragmento coronal extruído foi reposicionado e estabilizado com contenção flexível por quatro semanas. Prescrições de medicamentos e instruções foram dadas aos pais e ao paciente. As condições clínicas e radiográficas permaneceram satisfatórias nos acompanhamentos de 4 semanas, 6 meses e 12 meses. A vitalidade pulpar foi confirmada por testes térmicos e de percussão após 12 meses. A formação de tecido duro entre os segmentos fraturados foi observada no exame radiográfico e na tomografia computadorizada de feixe cónico. Em conclusão, a terapêutica conservadora imediata apresentou resultados clínicos e radiográficos satisfatórios.

Abstract This study evaluated how Er,Cr:YSGG laser, associated or not with 5% fluoride varnish, influences the surface roughness and volume loss of bovine root dentin submitted to erosive and/or abrasive wear. One hundred and twenty dentin specimens were divided into the groups: without preventive treatment (WPT), 5% fluoride varnish (FV); Er,Cr:YSGG laser irradiation (L), and varnish combined with laser (FV + L). The specimens (n = 10) were subdivided into: 1 = erosion (E); 2 = abrasion (A); and 3 = erosion followed by abrasion (E + A). The erosive solution used was a soft-drink (pH = 2.42 at 4ºC) applied in 5-min cycles twice a day for 10d. Abrasive wear involved brushing for 60s with an electric brush (1,600-oscillations/s) at a load of 2.0N. Surface roughness and volume loss were evaluated using a laser scanning confocal microscope. Roughness data were submitted to one-way ANOVA and Tukey post-hoc test. For volume loss, the Kruskal-Wallis and Dunn’s post-hoc tests were used (α = 5%). The lowest values of roughness were found in the control areas of all subgroups (p > 0.05). In the experimental area, the [(WPT) + (E+A)] subgroup had a significantly higher roughness (5.712 ± 0.163 μm 2 ) than the other subgroups (p < 0.05). The L and (FV + L) groups had statistically similar roughness, regardless of the type of wear. The (FV + L) group had the lowest volume loss, regardless of the type of wear performed: [(FV + L) + (E)] = 7.5%, [(FV + L) + (A) = 7.3%, and [(FV + L) + (E + A)] = 8.1%. The subgroup [(WPT) + (E + A)] had the highest volume loss (52.3%). The proposed treatments were effective in controlling dentin roughness. Laser irradiation can be an effective method to increase root dentin resistance after challenges and limit problems related to non-carious lesions.

OBJETIVO: Analisar a estabilidade primária de implantes odontológicos com tratamento e sem tratamento de superfície, por meio da frequência de ressonância, utilizando diferentes materiais como substratos substitutos do osso humano para sua inserção. MÉTODOS: Foram utilizados 16 implantes de titânio Conexão(r), cilíndricos, hexágono externo, com 11,5 mm de comprimento e 3,75 mm de largura, sendo: 8 Master Porous, com tratamento de superfície; e 8 Master Screw, usinados. A instalação de implantes foi realizada nos seguintes substratos: osso de costela suína, madeira, osso artificial de poliuretana da marca Nacional(r) (40, 20 e 15 PCF) e da marca Synbone(r). Foi avaliada a estabilidade primária através da frequência de ressonância utilizando o aparelho Osstell(tm) Mentor. Os dados obtidos foram submetidos a tratamento estatístico ANOVA e Teste de Tukey, com nível de significância a 5%. RESULTADOS: Foi constatado que, apesar de Master Porous apresentar maior valor que Master Screw em todos os substratos, estes não apresentaram diferença estatística entre si (p>0,05), com exceção da poliuretana Nacional(r) de 20 PCF. Quando inseridos no substrato madeira e na poliuretana Nacional(r) 40 PCF, Master Porous e Master Screw tiveram maiores valores. Master Porous, quando inserido no osso suíno também foram iguais estatisticamente a estas interações. CONCLUSÃO: Apesar de inovações nas características das superfícies de implantes serem desenvolvidas constantemente para contribuir no desempenho de implantes osseointegrados, e nosso estudo encontrar que não houve influência do tratamento de superfície na estabilidade primária aferida por frequência de ressonância; ainda há pouco conhecimento científico sobre esses efeitos.

OBJECTIVE: The aim of this study was to analyze the primary stability of dental implants with and without surface treatment, by means of resonance frequency, using different materials as substitutes for human bone substrates for insertion. METHODS: Sixteen external hexagon, cylindrical Conexão(r) titanium implants were used, 11.5 mm long by 3.75 mm wide, as follows: 8 Master Porous (MP), with surface treatment and 8 Master Screw (MS) machined. The implant placement was performed on the following substrates: pork rib bone, wood, artificial bone polyurethane National(r) (40, 20, 15 PCF) and Synbone(r). Primary stability was assessed via resonance frequency using an Osstell Mentor(tm) device. Data were analyzed statistically using ANOVA and Tukey's test, with a significance level of 5%. RESULTS: It was found that although MP and MS have a higher value on all substrates, these were not statistically different between groups (p>0.05), except for polyurethane National(r) 20 PCF. When inserted into the wood substrate and polyurethane National(r) 40 PCF, MP and MS had higher values. MP, when inserted into the pig bone, was also statistically equal to these interactions. CONCLUSION: Despite the continuous development of innovations in the characteristics of implant surfaces to assist with the performance of osseointegrated implants, and the fact that our study has found that the surface treatment had no impact on the primary stability checked using ressonance frequency, there is still very little scientific understanding of these effects.

The use of erbium lasers to prevent caries in enamel has shown positive results. However, it is not known if Er,Cr:YSGG laser can also be used to increase acid resistance of root dentine, which is another dental tissue susceptible to the action of cariogenic bacteria. Objective: To analyze the effects of the Er,Cr:YSGG laser (λ=2.78 μm, 20 Hz) irradiation associated with 2% neutral sodium fluoride (NaF) to prevent root dentin demineralization. Material and Methods: One hundred human root dentin samples were divided into 10 groups (G) and treated as follows: G1: no treatment; G2: NaF; G3: laser (4.64 J/cm2) with water cooling (WC=5.4 mL/min); G4: laser (4.64 J/cm2) without WC; G5: laser (8.92 J/cm2) with WC; G6: laser (8.92 J/cm2) without WC; G7: laser (4.64 J/cm2) with WC and NaF; G8: laser (4.64 J/cm2) without WC and NaF; G9: laser (8.92 J/cm2) with WC and NaF; G10: laser (8.92 J/cm2) without WC and NaF. The NaF gel was applied alone or after 4 min of irradiation. After 14 days of acid challenge, the samples were sectioned and the Knoop microhardness (KHN) test was done at different depths (30, 60, 90 and 120 μm) from the outer dentin surface. Data were analyzed by one-way ANOVA and Fisher’s test (α=5%). Results: The results showed that G8 and G10 presented higher KHN than the G1 for the depths of 30 and 60 μm, indicating an increase of the acid resistance of the dentin in up to 35% (p<0.05). Conclusions: The use of Er,Cr:YSGG laser irradiation at 4.64 J/ cm2 and 8.92 J/cm2 without water cooling and associated with 2% NaF can increase the acid resistance of human root dentin.

A alteração da microestrutura do implante durante seu manuseio pode reduzir o potencial do tratamento superfícial na osteoindução e consequentemente na osseointegração. O objetivo deste estudo foi avaliar o efeito do torque de inserção e do ensaio de arrancamento, na microestrutura de implantes odontológicos de diferentes formatos, por meio de espectometria de energia dispersiva de raios-X (EDS). Para a realização do estudo foram selecionados quatro modelos de implantes Conexão(r) (n=8): Cônico com tratamento de superfície (COTS), Cilíndrico com tratamento de superfície (CTS), Cilíndrico com duplo tratamento de superfície (CTSD) e Cilíndrico com superfície usinada (CSU). Antes e após a realização dos ensaios mecânicos, os parafusos foram submetidos à análise da composição química de suas superfícies, por meio de EDS. Os resultados obtidos com a análise microestrutural demonstraram a presença de três elementos químicos principais: Ti, C e O. Foi verificada alteração estatisticamente significante na concentração dos elementos Ti e C. O implante com duplo tratamento de superfície (CTSD) foi o que apresentou a maior redução do Ti e maior aumento do C. A partir dos dados obtidos foi possível concluir que a manipulação mecânica pode alterar a superfície dos implantes quanto à sua microestrutura. Sendo assim, o planejamento cirúrgico deve levar em conta a escolha do tratamento de superfície, pois uma vez que o implante é inserido e removido do leito ósseo suas características podem ser alteradas.

The change in the implant microstructure during handling may reduce the potential of surface treatment on the osteoinduction and, therefore, on the osseointegration. The aim of this study was to evaluate by energy-dispersive X-ray spectroscopy (EDX) the effect of insertion torque and pullout test on the microstructure of dental implants with different shapes. Four shapes of implants (n=8) were selected: conical with surface treatment (COTS), cylindrical with surface treatment (CTS), cylindrical with double surface treatment (CTSD) and cylindrical with machined surface (CSU). Before and after performing the mechanical tests, the screw surfaces were subjected to analysis of chemical composition by EDX. The results obtained by the microstructural analysis showed presence of three main chemical elements: Ti, C and O. There was a significant change in the concentration of Ti and C. The implant with double surface treatment (CTSD) showed the greatest Ti reduction and the greatest C increase. It may be concluded that the mechanical manipulation may alter the implant surfaces as regards their microstructure. Therefore, surgical planning should take into consideration the choice of surface treatment because the characteristics of the implants may be modified as they are inserted and removed from the bone site.

AIM: To evaluate the influence of the format and surface treatment of implants, as well as the substrate used in primary stability. METHODS: Thirty-two Conexão® implants were used: 8 conical (CC) (11.5 x 3.5 mm) and 24 cylindrical (11.5 x 3.75 mm) - 8 external hexagon implants without surface treatment (MS), 8 external hexagon implants with double Porous treatment (MP), 8 internal hexagon implants with Porous treatment (CA). They were inserted in Nacional® polyurethane in three densities (15, 20 and 40 PCF). The insertion torque (IT) (N.cm) was quantified using the digital Mackena® torque meter, and the pullout force (PF) (N) by means of axial traction force with a 200 kg load cell, performed in a Universal Test Machine (Emic® DL10000) and the Tesc 3.13 software. Data were analyzed statistically by ANOVA and Tukey's test with a significance level of 5%. RESULTS: Difference was observed between groups (p<0.05). Regarding the IT, MP and MS inserted to the substrate 40PCF showed higher values with statistically significant difference with all interactions implants x substrate; the 15 and 20PCF densities was not significant in all groups of implants. MP, MS, CC and CA did not differ significantly, even inserted in a lower density, where CC showed better IT compared with other densities. For PF, the best performance was the interaction implant CA x 40PCF substrate, showing a difference from the other implants inserted in all substrates. CONCLUSIONS: The higher bone density and cylindrical implants with surface treatment provides greater IT and PF.