Influence of chemical degradation and abrasion on surface properties of nanorestorative materials

Aim: The aim of this in vitro study was to investigate the synergistic effect of chemical degradation (erosion) and three-body abrasion (mechanical degradation) on the surface roughness (Ra) and hardness (KHN) of two nanorestorative materials and two conventional materials. Methods: Discshaped specimens (5 mm in diameter, 2 mm thick) of Filtek Z350™ and TPH Spectrum™ composites and Ketac Nano™ and Vitremer™ light-curing glass ionomer cements, nanomaterials and conventional materials were prepared according to the manufacturer's instructions. After 24 h, polishing procedures were performed and initial measurements of Ra and KHN were taken in all specimens. The specimens were divided into 12 groups (n = 10) according to material and storage media: artificial saliva, orange juice, and Coca-Cola®. After 30 days of storage, the specimens were submitted to mechanical degradation and re-evaluated for Ra and KHN. Data were tested for significant differences by repeated-measure three-way ANOVA and Tukey's tests (p<0.05). Results: Erosion and abrasion wear significantly decreased hardness of all materials. Only Filtek Z350 roughness, however, was not affected by erosion and abrasion. All materials showed a significant increase in surface roughness after erosion and abrasion, except for Filtek Z350. After chemical and mechanical degradation, the KHN of all samples had decreased significantly. After mechanical degradation, the acidic drinks (Coca-Cola® and orange juice) were more aggressive than artificial saliva to all materials. Conclusions: A synergistic effect was observed by the increase in roughness for all materials, except for Filtek Z350; hardness values decrease for all materials, regardless of whether they were nanofilled or not. The RMGICs were more susceptible to degradation than the composites, considering both hardness and roughness surface parameters142100105sem informaçã

Nasal breathing after removing sucking habit and myofunctional therapy

PURPOSE: to evaluate the influence of removing pacifier and baby bottle sucking habit and Myofunctional Therapy in increasing nasal airing. METHODS: twenty children aged up to four year, were distributed in two groups according to the treatment, and named: REM Group (only submitted to habits removal) and FMT Group (submitted to habits removal and later to Myofunctional Therapy). The data obtained from the air flow expired by the nostrils were obtained by using the millimeter nasal mirror of Altmann and quantified in millimeter paper (reference block). The exams were accomplished in three times (pre-treatment, 60 and 180 days after treatment). The data were submitted to t Test for two independent samples and the paired t Test (p < 0.05). RESULTS: it was observed that the increase of the nasal airing after treatments were significantly superior for the FMT Group than for the REM Group (p < 0.0001). CONCLUSION: Myofunctional Therapy was able to improve increase of nasal airing and consequently enhancement of nasal breathing.OBJETIVO: avaliar os efeitos da associação entre a remoção de hábitos de sucção e a Terapia Miofuncional Orofacial na ampliação da aeração nasal. MÉTODOS: vinte crianças na faixa de etária de quatro anos a quatro anos e oito meses foram distribuídas em dois grupos denominados de: Grupo REM (submetido apenas à remoção de hábitos) e Grupo TMF (submetido à remoção de hábitos e posteriormente à Terapia Miofuncional Orofacial). O fluxo de ar expirado pelas narinas foi registrado por meio do espelho nasal milimetrado de Altmann e quantificado em papel milimetrado denominado de Bloco de Referência do Espelho de Altmann. Os exames foram realizados em três momentos (pré-tratamento, 60 e 180 dias após). Os resultados foram submetidos à análise estatística, utilizando-se Test t para duas amostras independentes e para dados pareados, considerando nível de significância valores p<0,05. RESULTADOS: pode-se observar que as médias obtidas da quantificação da aeração nasal após os tratamentos foram significativamente maiores no Grupo TMF que no Grupo REM (p< 0,0001). CONCLUSÃO: houve aumento da aeração nasal e conseqüentemente melhora da função respiratória nasal, utilizando a Terapia Miofuncional Orofacial após remoção de hábitos de sucção em crianças na faixa etária de quatro anos.5560Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Avaliação do pré-tratamento de MI Paste™ e diferentes sistemas adesivos na µTBS da dentina desmineralizada.

O objetivo do presente estudo foi avaliar o efeito de MI Paste™ e dois sistemas adesivos (Adper™ Single Bond 2-SB e Clearfil™ SE Bond-CSE) na resistência de união à microtração (µTBS) da dentina desmineralizada. 36 blocos de dentina média obtidos foram distribuídos em 6 grupos (n=6): G1 - Dentina Hígida/SB - DH/SB; G2 - DH/CSE - DH/CSE; G3–DentinaDesmineralizada/SB - DD/SB; G4–DD/CSE; G5-DD+MI Paste™-MP/SB - DD+MP/SB; e G6–DD+MP/CSE. Blocos de compósito FiltekTM Z350XT (4mm) foram construídos sobre a dentina com SB ou CSE e os conjuntos armazenados por 24h a 37ºC em água destilada. Palitos (1mm ­ área de secção) foram obtidos e submetidos ao teste de μTBS (1,0mm/min ­ 500N). Os dados de μTBS (MPa) foram submetidos à ANOVA e teste de Tukey, e Dunnett (α=5%). Os tipos de fraturas foram avaliados por MEV. Houve interação significativa dos dados de μTBS, entre os fatores (Adesivo/Substrato) (

Morphological And Chemical Changes In Dentin After Using Endodontic Agents: Fourier Transform Raman Spectroscopy, Energy-dispersive X-ray Fluorescence Spectrometry, And Scanning Electron Microscopy Study.

We examine the morphological and chemical changes in the pulp chamber dentin after using endodontic agents by scanning electron microscopy (SEM), Fourier transform Raman spectroscopy (FT-Raman), and micro energy-dispersive x-ray fluorescence spectrometry (μEDXRF). Thirty teeth were sectioned exposing the pulp chamber and divided by six groups (n=5): NT-no treatment; CHX-2% chlorhexidine; CHXE-2% chlorhexidine+17% EDTA; E-17% EDTA; SH5-5.25% NaOCl; SH5E-5.25% NaOCl+17% EDTA. The inorganic and organic content was analyzed by FT-Raman. μEDXRF examined calcium (Ca) and phosphorus (P) content as well as Ca/P ratio. Impressions of specimens were evaluated by SEM. Data were submitted to Kruskal-Wallis and Dunn tests (pNT=SH5E>CHX>E>CHXE). CHXE and E presented the highest Ca/P ratio values compared to the other groups (p<0.05). The SEM images in the EDTA-treated groups had the highest number of open tubules. Erosion in the tubules was observed in CHX and SH5E groups. Endodontic agents change the inorganic and organic content of pulp chamber dentin. NaOCl used alone, or in association with EDTA, was the most effective agent considering chemical and morphological approaches.1707500

Efeito da contaminação salivar e do tempo de recondicionamento ácido na resistência da união ao cisalhamento de um selante de fóssulas e fissuras

O propósito deste estudo foi avaliar o efeito do tempo de contaminação salivar (TCS) e de recondicionamento ácido (TRA) na resistência da união ao cisalhamento (RC) do selante Fluroshield. Foram selecionados 45 terceiros molares. Os dentes foram seccionados no sentido mésio-distal e suas superfícies foram lixadas até a obtenção de uma área plana em esmalte. Em seguida, as amostras foram distribuídas aleatoriamente em 9 grupos (n=10), em função do TCS e TRA (segundos), respectivamente: G1 - controle; G2 - 30 e 0; G3 - 60 e 0; G4 - 30 e 2; G5 - 30 e 5; G6 - 30 e 15; G7 - 60 e 2; G8 - 60 e 5; G9 - 60 e 15. Em seguida, foi realizada a aplicação do selante de acordo com as instruções do fabricante. Os corpos-de-prova obtidos foram armazenados em água destilada a 37&ordm;C por 72 horas, e então submetidos ao ensaio de cisalhamento à velocidade de 0,5mm/min. Os resultados foram submetidos à análise de variância (ANOVA), e indicaram que não houve diferença estatística significativa (p>;0,05) entre todos os grupos. Observou-se que: 1 - quanto maior o TCS, menores os valores de RC (MPa); 2- quanto maior o TRA, maior o valor de RC (MPa). Pôde-se concluir que houve uma tendência para o menor TCS (30s) e os maiores TRA (5 e 15s) em retornar aos valores de RC do grupo controle.The aim of this study was to evaluate the effect of saliva contamination (SCT) and re-etching time (RET) on the shear bond strength (SBS) of the Fluroshield sealant. Forty-five extracted third molars were sectioned and flattened until reach an enamel surface area. Then, all samples were etched for 30 sec with 35% phosphoric acid and then they were distributed into 9 groups (n=10) according to SCT and RET (seconds), respectively: G1- control (no SCT and no RET); G2- 30s and 0s; G3- 60s and 0s; G4-30s and 2s; G5- 30s and 5s; G6- 30s and 15s; G7-60s and 2s; G8- 60s and 5s; G9- 60s and 15s. The sealant was applied according to the manufacturer's instructions. The samples were stored in distilled water at 37&ordm;C for 72h and subjected to the SBS test. The results indicated that there was no statistically significant difference between the groups (p>;0.05). However, it could be noticed that: 1- the longer the SCT, the lower the SBS values; 2 - the longer the RET, the higher the SBS values. It could be concluded that there was a tendency to the shortest SCT (30s) associated to the longest RET (5 and 15s) to reach similar SBS values for the control group

Aesthetic and functional rehabilitation of anterior teeth after trauma: a case report

Traumatic dental injuries are common clinical problems during childhood, and may have complex etiologies causing physical and physiological impairment. The aim of this study was to report the management of a severe traumatic dental injury in an 8-year-old female patient, victim of a motorcycle accident, who was taken to a pediatric dentistry clinic three months after the accident. After clinical and radiografic examination, we observed the avulsion of the permanent maxillary central incisors and of the permanent left lateral incisor, with considerable lingual interposition, interfering in speech and swallowing. The patient showed low risk of caries and good behavior during the appointments. However, she demonstrated to be embarrassed to smile. Besides the preventive treatment concerning caries, the treatment plan included immediate care and subsequent monitoring of the psychosocial reestablishment. For this purpose, an acrylic partial denture was made in order to replace the missing anterior teeth, maintaining the characteristics of the mixed dentition and preserving the aesthetics and the function. Follow-up appointments were performed one, three and six months after the first visit, aiming to monitor the adaptation of the prosthesis, as well as the growth and development of the child’s dentition. Thus, the aesthetic and functional rehabilitation was achieved regarding the patient’s satisfaction, enabling immediate social reinsertion.Lesões dentárias traumáticas são problemas clínicos comuns durante a infância e podem ter etiologias complexas, causando deficiências físicas e fisiológicas. O objetivo deste estudo foi relatar um caso de lesão dentária traumática grave em uma paciente de 8 anos de idade, vítima de um acidente de moto, que foi levada para uma clínica de odontopediatria três meses depois do acidente. Exames clínicos e radiológicos diagnosticaram a avulsão dos incisivos centrais superiores permanentes, do incisivo lateral esquerdo permanente e do canino esquerdo decíduo, com considerável interposição da língua, interferindo na fala e deglutição. A paciente apresentou baixo risco de cárie e bom comportamento durante as consultas. No entanto, ela demonstrou estar envergonhada para sorrir. Além do tratamento preventivo para a cárie, o plano de tratamento incluiu atendimento imediato e acompanhamento posterior do restabelecimento psicossocial da paciente. Para este efeito, uma prótese parcial acrílica foi feita para substituir os dentes anteriores que faltavam, mantendo as características da dentição mista e preservando sua estética e função. Consultas de acompanhamento foram realizadas em um, três e seis meses após a primeira visita, com o objetivo de monitorar a adaptação da prótese, bem como o crescimento e desenvolvimento da dentição da criança. Assim, a reabilitação estética e funcional foi alcançada considerando a satisfação da paciente, permitindo sua reinserção social imediata

Effect of the Polishing Procedures on Color Stability and Surface Roughness of Composite Resins

Objectives. To evaluate the polishing procedures effect on color stability and surface roughness of composite resins. Methods. Specimens were distributed into 6 groups: G1: Filtek Supreme XT + PoGo; G2: Filtek Supreme XT + Sof-Lex; G3: Filtek Supreme XT + no polishing; G4: Amelogen + PoGo; G5: Amelogen + Sof-Lex.; G6: Amelogen + no polishing. Initial color values were evaluated using the CIELab scale. After polishing, surface roughness was evaluated and the specimens were stored in coffee solution at 37°C for 7 days. The final color measurement and roughness were determined. Results. Sof-Lex resulted in lower staining. Amelogen showed the highest roughness values than Filtek Supreme on baseline and final evaluations regardless of the polishing technique. Filtek Supreme polished with PoGo showed the lowest roughness values. All groups presented discoloration after storage in coffee solution, regardless of the polishing technique. Conclusion. Multiple-step polishing technique provided lower degree of discoloration for both composite resins. The final surface texture is material and technique dependent

Influence of environmental conditions on properties of ionomeric and resin sealant materials

OBJECTIVES: The aim of this study was to determine the effect of environmental conditions on the degradation of ionomeric and resin sealant materials. MATERIAL AND METHODS: FluroShield, Vitremer, and Ketac Molar disc-shaped specimens (n=18/material) were prepared, polished, subjected to initial hardness and roughness readings. Six discs of each material were randomly assigned to one of three different storage solutions: 0.3% citric acid (CA), demineralization solution (DE), and remineralization solution (RE). The specimens were individually immersed in 3 mL of the test solutions, which were daily changed. After 15 days of storage, new surface roughness and hardness readings were done. Fluoride release in the solutions was measured within 15 days. Data were analyzed by ANOVA and Tukey's and Contrast tests (&#945;=0.05). RESULTS: The storage in CA increased the roughness of Vitremer and Ketac Molar. A significant reduction in hardness was observed for all materials after storage in all solutions. For all materials, the greatest amounts of fluoride release occurred during the 1st day. FluroShield presented the same patterns of fluoride release in all solutions. Ketac Molar and Vitremer released the highest amounts of fluoride in the CA solution. CONCLUSIONS: Ionomeric materials are more susceptible to degradation than resin-based materials under acidic conditions. Acidic conditions lead to a higher fluoride release from ionomeric materials

Chx stabilizes the resin/demineralized dentin interface

The aim of this study was to evaluate the effect of 2% chlorhexidine diglueonate (CHX) on microtensile bond strength (μTBS) between an adhesive system and under 3 dentin conditions. For that, this study evaluated the adhesive interface at initial, after 6 months and 1 year of storage. Forty-eight human third molars were prepared and randomly divided into 3 groups, according to dentin substrates: Sound dentin (Sd), caries-infected dentin (Ci) and caries-affected dentin (Ca). The groups were subdivided into two according to the dentin pre-treatment: Application of 2% CHX or without pre-treatment (control). The dentin surfaces were etched with 35% phosphoric acid gel and bonded with Adper Single Bond 2 (3M ESPE) adhesive system according to manufacturer's instructions. Subsequently, the specimens were stored in deionized water at 37°C for 24h, 6 months and 1 year. Two additional teeth were used to analyze the bonding interfaces by SEM. Data was submitted to three-way ANOVA in a split plot design and Tukey's test (α = 0.05). The results showed that Ci decreased μTBS values when compared to Ca and Sd, regardless storages time or treatment. Stored samples for 6 months and 1 year decreased the pTBS for the control group, but no difference was found between storages time for the CHX group. As a conclusion, the 2% CHX application after etching showed improved dentin bond strength in the storage time, regardless of the substrates evaluated