A procura pela estética para se obter um sorriso saudável e atrativo tem aumentado. O objetivo desse artigo é relatar um caso de dois incisivos laterais com morfologia conoide e diastemas com distribuição desproporcional, que teve remodelação estética por meio de movimentação ortodôntica, aumento de coroa e resina composta. Uma paciente jovem procurou tratamento porque estava insatisfeita com seu sorriso, devido à presença de dentes conoides e diastemas. Além disso, a harmonia do sorriso era afetada pela presença de um desnível do zênite gengival dos incisivos centrais. Para planejamento do caso, foi realizado um modelo diagnóstico e observada a necessidade de movimentação ortodôntica, para redistribuição dos espaços presentes nos diastemas, e cirurgia periodontal, para elevar a margem gengival dos incisivos centrais. Após o período de preparo, foi feito clareamento caseiro e posteriormente o tratamento restaurador com resina composta. Após o controle de 7 meses, pode-se observar ausência de inflamação gengival, além de um sorriso harmônico e estético.
Simplified dentin-bonding systems are clinically employed for most adhesive procedures, and they are prone to hydrolytic degradation. Objective This study aimed to investigate the effect of laser diode irradiation on the degree of conversion (DC), water sorption (WS), and water solubility (WSB) of these bonding systems in an attempt to improve their physico-mechanical resistance.Material and Methods Two bonding agents were tested: a two-step total-etch system [Adper™ Single Bond 2, 3M ESPE (SB)] and a universal system [Adper™ Single Bond Universal, 3M ESPE (SU)]. Square-shaped specimens were prepared and assigned into 4 groups (n=5): SB and SU (control groups – no laser irradiation) and SB-L and SU-L [SB and SU laser (L) – irradiated groups]. DC was assessed using Fourier transform infrared spectroscopy with attenuated total reflectance. Additional uncured resin samples (≈3.0 µL, n=5) of each adhesive were also scanned for final DC calculation. For WS/WSB tests, similar specimens (n=10) were prepared and measured by monitoring the mass changes after dehydration/water storage cycles. For both tests, adhesive fluids were dropped into standardized Teflon molds (6.0×6.0×1.0 mm), irradiated with a 970-nm laser diode, and then polymerized with an LED-curing unit (1 W/cm2).Results Laser irradiation immediately before photopolymerization increased the DC (%) of the tested adhesives: SB-L>SB>SU-L>SU. For WS/WSB (μg/mm3), only the dentin bonding system (DBS) was a significant factor (p<0.05): SB>SU.Conclusion Irradiation with a laser diode improved the degree of conversion of all tested simplified dentin bonding systems, with no impact on water sorption and solubility.
Objective. To evaluate the effect of an experimental gel containing Euclea natalensis extract on dentin permeability. Methods. Thirty-six dentin discs, 1-mm-thick. The discs were prepared from the coronal dentin of extracted human third molars that were divided into 3 groups (n = 10). The dentin discs in each group were treated with the groups following experimental materials: (FG): 1.23% fluoride gel, pH 4.1; (EG): Euclea natalensis extract gel, pH 4.1; (CG): control gel, pH 4.1. The gels were applied to the occlusal slide of the dentin under the following conditions: after 37% phosphoric acid and before 6% citric acid. The hydraulic conductance (HC) of each condition was determined four times using a fluid flow apparatus (Flodec). The data were analyzed using Two-way ANOVA and Tukey's test (P < 0.05). Results. The greatest mean reduction in HC was produced in group EG dentin discs (61.2%; P < 0.05). Even after acid challenge with 6% citric acid the great reduction occurred in group EG (66.0%; P < 0.05) than other groups (CG-77.1%, FG-90.8%). Conclusion. E. natalensis gel not only reduced dentin permeability, but also resisted posttreatment citric acid challenge without changing its permeability. Further research has to confirm this promising result in the clinical situation.
Objectives:The aim of this in vitro study was to evaluate the bonding strength of non-simplified dentin bonding systems (DBS) to dentin irradiated with a diode laser (970 nm) immediately and after 12 months of water storage following either primer or bond application.Material and methods:The experimental design included three different factors: DBS type [AdperTM Scotchbond Multipurpose (MP) and Clearfil™ SE Bond (CSE)], irradiation [without irradiation - control (C), irradiation after primer application (AP), and irradiation after bond application (AB)], and time [initial (I) and after 12 months of water storage (12 m)]. Sixty sound human third molars (n = 10) were obtained, and their flat occlusal dentin areas were prepared and standardized. Laser irradiation was performed in the contact mode perpendicular to the dental surface over an automatically selected scanning area at a pulse energy of 0.8 W, frequency of 10 Hz, and energy density of 66.67 J/cm2. After 7 days of treatment, the specimens were cut, and half of them were subjected to microtensile testing (500 N/0.05 mm/min), whereas the remaining sticks were examined after 12 months of water storage. The obtained data were analyzed by three-way analysis of variance (ANOVA) followed by a Tukey test (p<0.05). The observed fracture modes were investigated using a portable digital microscope with a magnification of 40x.Results:Among the utilized DBS, MP generally exhibited higher bond strengths, but did not always differ from CSE under similar conditions. The irradiation factor was statistically significant only for the MP/AB groups. After 12 months of storage, all groups demonstrated a significant reduction in the bond strength, whereas the results of fracture analysis showed a predominance of the adhesive type.Conclusions:The laser treatment of non-simplified DBS was not able to stabilize their bonding characteristics after 12 months.
This study aimed to evaluate the polymerization properties of bulk-fill materials (low and high-viscosity) by using high-intensity continuous light and intermittent photo-activation in terms of polymerization shrinkage stress and degree of conversion (DC). The following Bulk-fill and Conventional nanofilled resin composites were evaluated: Filtek Z350XT Flow (3M/ESPE), SureFil SDR Flow (Dentsply), Filtek Bulk Fill Flow (3M/ESPE), Filtek Z350XT (3M/ESPE) and Filtek Bulk Fill Posterior (3M/ESPE). A LED device (DB 685, Dabi Atlante) was used for both protocols: continuous uniform and intermittent photo-activation (light-on and light-off cycles) with identical radiant exposure (14 J/cm2). The polymerization shrinkage stress (n=6) was evaluated by inserting a single increment of 12 mm3 between two stainless steel plates (6×2 mm) adapted to a Universal Testing Machine (UTM), at different times. Measurements were recorded after photo-activation. The degree of conversion was evaluated by Fourier transformed infrared spectroscope (FTIR) with an attenuated total reflectance (ATR) accessory (n=5). Data were analyzed by three-way ANOVA and Tukey’s HSD (α=0.05) tests. Bulk Fill Posterior presented higher shrinkage stress values when photo-activated with the intermittent technique (p<0.05). The intermittent photo-activation increased the degree of conversion for the low-viscosity bulk-fills (p<0.05). Therefore, the use of modulated photo-activation (intermittent) must be indicated with caution since its use can influence the shrinkage stress and degree of conversion of composites, which varies according to the resin formulations.
<p>This study evaluated the influence of residual eugenol on the tensile strength in the ceromer crowns cementation, using resin cement. Thirty-nine third molars were prepared for a full crown. For each prepared tooth one provisional and one ceromer crown were made. The teeth were divided into three groups according the temporary cement (n=13): GTB: Temp Bond; GTBNE: Temp Bond NE and GDY: Dycal. After temporary cementation, the teeth were kept in distilled water for one week and then submitted to traction test in a universal testing machine (EMIC DL 500), using a 200Kgf load cell at 0.5mm/min speed. After the test, the teeth were cleaned and received the final adhesive cementation of ceromer crowns. Next, the specimens were kept in distilled water (37<sup>0</sup>C) for a week and then the traction test was performed, also at 0,5mm/min. The comparison among groups was carried out by variance analysis (ANOVA) followed by the Tukey test (p≤0.05). The results (Kgf) of provisional cementation for groups GTB, GTBNE and GDY were respectively: 2.75 ± 1.35b, 3.43 ± 1.66ab, and 4.48 ± 1.11a. The results of the adhesive cementation (Kgf) were respectively: 42.71 ± 15.33b, 57.59 ± 15.66a, and 54.75 ± 15.28ab. It was concluded that the temporary cement containing eugenol shows negative influence on the removal resistance of crowns cemented with resin cement. </p>
Patients who undergo radiotherapy for head-and-neck cancer usually present oral complications that impair their quality of life. This clinical case presents the advantage of using a semi-direct technique with bioactive materials to restore compromised posterior teeth by dental professionals who participate as members of the oncology network support team to provide long-lasting treatment in a shorter time. Post-radiotherapy patients presented several oral challenges, including the presence of radiation-induced caries. In addition, the left maxillary second premolar showed unsatisfactory class II restoration. For radiation caries lesions, glass-ionomer cement restorations were performed. For the unsatisfactory class II restorations, semi-direct technique using resin composite was used. Glass ionomer-based restorations offer appropriate marginal adaptation and reduced sensitivity. For the semi-direct restorations, adequate anatomical contour, contact point, and occlusal contact were achieved using relevant clinical parameters. For patients who have had head-and-neck radiotherapy, restoration of affected teeth is relevant for improving their dental function to avoid malnutrition and to recover their quality of life, including esthetics and self-esteem. This semi-direct procedure reduced chairside time, which is beneficial also for the professionals. Using bioactive materials and person-centered care concept, technical and long-term benefits can be achieved.
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