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Papers by Rafael Patzlaff

Objective: This study evaluated the effect of application mode of three simplified etch-and-rinse... more Objective: This study evaluated the effect of application mode of three simplified etch-and-rinse adhesives on the push-out bond strength (PBS), nanoleakage (NL) and in situ degree of conversion (DC) of fiber posts in the root canal Method: The roots of human premolars were endodontically prepared and divided into six groups according to the combination of the main factors Adhesive (Ambar, Adper Single Bond 2 and XP Bond+self-cure activator) and Application mode (manual or sonic). The posts were cemented and the PBS tested at 0.5 mm/min. The NL was evaluated by SEM after immersion of specimens in 50% silver nitrate. Micro-Raman spectroscopy was used to measure the in situ DC. Data were analyzed by three-way repeated measures ANOVA and Tukey tests (5%). Result: Under manual application, the PBS of the apical and cervical third showed the lowest and highest means respectively. Under sonic application, the PBS values increased significantly mainly in the middle and apical thirds. Under...

The journal of adhesive dentistry, 2014

This study evaluated the effects of light exposure times on water sorption, solubility, and polym... more This study evaluated the effects of light exposure times on water sorption, solubility, and polymer cross-linking density of simplified etch-and-rinse adhesives. Four commercial adhesives (XP Bond, Adper Single Bond 2, Tetric N-Bond, and Ambar) were selected, and resin disks 5 mm in diameter and 1.0 mm thick were prepared and light cured for 20, 40, or 80 s using an LED light-curing unit at 1200 mW/cm2. Water sorption and solubility were evaluated over a 28-day period. For polymer cross-linking density, additional specimens were prepared and their Knoop hardness measured before and after immersion in 100% ethanol. The data from each test were evaluated using a two-way ANOVA and Tukey's test (α = 0.05). The XP Bond adhesive showed higher water sorption (similar to Adper Single Bond 2) and solubility (p < 0.05) than did the other materials. Prolonged exposure times did not reduce the water sorption but did reduce the solubility of all tested materials (p < 0.05). For Ambar, ...

Journal of Endodontics, 2014

Introduction: Luting posts inside the root canal is still a challenge because of the difficulty o... more Introduction: Luting posts inside the root canal is still a challenge because of the difficulty of bonding adhesive materials in the apical third of roots. This study evaluated the effect of the application mode of 3 simplified etch-and-rinse adhesives on the push-out bond strength (PBS), nanoleakage (NL), and in situ degree of conversion (DC) of fiber posts in the root canal. Methods: The roots of human premolars were endodontically prepared and divided into 6 groups according to the combination of the main factors: adhesive (Ambar, FGM, Joinville, SC, Brazil; Adper Single Bond 2, 3MESPE, St Paul, MN; and XP Bond+self-cure activator, DeTrey Dentsply, Konstanz, Germany) and application mode (manual or sonic). The posts were cemented and the PBS tested at 0.5 mm/min. The NL was evaluated by scanning electron microscopy after the immersion of specimens in 50% silver nitrate. Micro-Raman spectroscopy was used to measure the in situ DC. Root third was also considered in the statistical evaluation. Data were analyzed by 3-way repeated measures analysis of variance and Tukey tests (5%). Results: Under sonic application, the PBS and the in situ DC increased, whereas NL decreased significantly for all groups in the middle and apical thirds (P < .05). Conclusions: The application of simplified adhesives by sonic mode in the root canal is a feasible tool to increase the fiber post bond to root canals. (J Endod 2014;40:1201-1205

Operative Dentistry, 2008

Objective: To examine the morphological, early and long-term microtensile bond strengths (µTBS) o... more Objective: To examine the morphological, early and long-term microtensile bond strengths (µTBS) of one-step self-etch systems to unground and ground enamel.

Operative Dentistry, 2007

Operative Dentistry, 2007, 32-4, 380-387

$Research paper thumbnail of Performance of techniques used for re-attachment of endodontically treated crown fractured teeth$

Journal of Dentistry, 2008

The aim of this study was to compare the fracture strength of three techniques used to re-attach ... more The aim of this study was to compare the fracture strength of three techniques used to re-attach tooth fragments in sound and endodontically treated fractured teeth with or without fiber post placement. Ninety human lower incisors were randomly divided into three groups of 30 teeth each. In group A teeth were not subjected to endodontic treatment; while teeth from groups B and C were endodontically treated and the pulp chamber restored with a composite resin. All teeth were fractured by an axial load applied to the buccal area in order to obtain tooth fragments. Teeth from each group were then divided into three subgroups, according to the re-attachment technique: bonded-only, buccal-chamfer and circumferential chamfer. Before the re-attachment procedures, fiber posts were placed in teeth from group C using dual cure resin luting cement (Duo-Link). All teeth (groups A-C) had the fragments re-attached using a same dual cure resin luting cement. In the bonded-only group, no additional preparation was made. After re-attachment of the fragment, teeth from groups buccal and circumferential chamfer groups had a 1.0 mm depth chamfer placed in the fracture line either on buccal surface or along the buccal and lingual surfaces, respectively. Increments of microhybid composite resin (Tetric Ceram) were used in subgroups buccal chamfer and circumferential chamfer to restore the chamfer. The specimens were loaded until fracture in the same pre-determined area. The force required to detach each fragment was recorded and the data was subjected to a three-way analysis of variance where factors Group and Re-attachment technique are independent measures and Time of fracture is a repeated measure factor (first and second) and Tukey&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s test (alpha=0.05). The main factors Re-attachment technique (p=0.04) and Time of fracture (p=0.02) were statistically significant. The buccal and circumferential chamfer techniques were statistically similar (p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;0.05) and superior to the bonded-only group (p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.05). The first time of fracture was statistically superior to second time of fracture (p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001). The use of fiber post is not necessary for the reinforcement of the tooth structure in re-attachment of endodontically treated teeth. When bonding a fractured fragment, the buccal or circumferential re-attachment techniques should be preferable in comparison with the simple re-attachment without any additional preparation. None of the techniques used for re-attachment restored the fracture strength of the intact teeth.

Journal of Dentistry, 2005

Self-etching adhesives; Total-etch adhesives; Smear layer thickness; Microtensile test; Ultimate ... more Self-etching adhesives; Total-etch adhesives; Smear layer thickness; Microtensile test; Ultimate microtensile strength; Long-term bond strength; Resin-dentin bond strength; Dentin adhesion

Clinical Oral Investigations, 2014

Objectives This study aims to evaluate the effect of different application modes on the immediate... more Objectives This study aims to evaluate the effect of different application modes on the immediate and 6-month resindentin bond strength (μTBS) and nanoleakage in the hybrid and adhesive layers. Materials and methods Three 1-step self-etch adhesives (One Coat 7.0 (OC), Clearfil S 3 Bond (CS), and FuturaBond NR (FB)) were applied on a flat superficial dentin surface of 30 human molars under manual mode or sonic vibration at a frequency of 170 Hz (SV). Composite build-ups were constructed incrementally; specimens were sectioned to obtain resin-dentin sticks with cross-sectional area of 0.8 mm 2 and tested in tension (0.5 mm/min) immediately (IM) or after 6 months (6M) of water storage. Two bonded sticks, from each tooth at each storage time, were immersed in a silver nitrate solution, photo-developed, and analyzed under scanning electron microscopy. The amount of nanoleakage was measured using the ImageTool 3.0 software. Data, from each adhesive, were analyzed by two-way ANOVA and Tukey's test (α=0.05). Results OC and CS showed higher μTBS and lower nanoleakage in the IM period when applied with SV groups. For FB, no significant difference was observed between the two modes of application. All materials showed lower nanoleakage in the SV groups. Higher nanoleakage was observed after 6M for OC and FB. Conclusions The sonic application mode at an oscillating frequency of 170 Hz can improve the resin-dentin μTBS, reduce the nanoleakage, and retard the degradation of the resin-dentin μTBS of Clearfil S 3 Bond and One Coat 7.0 adhesives. Clinical significance Sonic application mode at an oscillating frequency of 170 Hz can be helpful and easy to use in dental practice to guaranty long-lasting restorations.