Effect of surface characteristics of soft liners and tissue conditioners and saliva on the adhesion and biofilm formation.

PURPOSE: To investigate the influence of surface characteristics and saliva on the adhesion and biofilm formation of Candida glabrata and methicillin-resistant Staphylococcus aureus (MRSA) to soft liners and tissue conditioners. METHODS: For each material (Ufi Gel P - UG; Sofreliner S - SS; Trusoft - TR; Coe Comfort - CC; Softone - ST), specimens were prepared and roughness (Ra), hydrophobicity (water contact angles-WCA) and surface free energy (SFE) were measured. Surface morphology was also analyzed using scanning electron microscopy (SEM). Specimens were incubated in C. glabrata or MRSA suspensions for 90 minutes (adhesion) or 48 hours (biofilm). The absorbance (AB) was measured by XTT assay. Experiments were performed using specimens that were either uncoated or had been coated with saliva. Data were analyzed using one- or two-way ANOVAs, followed by Tukey's test (α= 0.05). RESULTS: TR exhibited the highest Ra and UG the lowest. SEM images also showed that UG and SS had smooth surfaces, while TR presented several irregularities and pores. In the absence of saliva, UG and SS presented higher WCA and lower SFE than the other materials. XTT results showed that, in the C. glabrata adhesion assay, the AB value was higher for TR followed by UG > CC> SS> ST. For the biofilm formation of C. glabrata, AB values were in the following order TR > CC = UG > ST = SS. In the adhesion assay, AB values obtained for MRSA were TR > UG = CC > ST > SS and for the biofilm formation were TR > ST > CC > UG > SS. Saliva decreased the WCA and increased the SFE for all materials. In general, the presence of saliva decreased the adhesion and biofilm formation of both microorganisms to the acrylic-based material (TR) and tissue conditioners (CC and ST), and increased for the silicone-based soft liners (UH and SS). Surface characteristics and the influence of saliva varied among materials. Roughness seemed to favor C. glabrata and MRSA adhesion and biofilm formation. CLINICAL SIGNIFICANCE: The presence of microorganisms on denture liners can irritate the oral tissues and contribute to systemic diseases. Colonization with more tolerant microorganisms such as C. glabrata and MRSA may expose patients to a greater risk of infection, mainly in immunocompromised hosts, such as aged individuals after treatment of oral cancer. For this, it is important to investigate the surface characteristics of soft liners and tissue conditioners, as well as saliva, and their influence on the adhesion and biofilm formation of C. glabrata and methicillin-resistant Staphylococcus aureus.

Occlusal Pressure Analysis of Complete Dentures after Microwave Disinfection: A Clinical Study.

PURPOSE: This clinical study evaluated the effect of microwave disinfection protocols on the occlusal pressure pattern of dentures. MATERIALS AND METHODS: Dentures were constructed for 40 patients and evaluated as follows (n = 20). Group 1: Patients had the maxillary dentures submitted to microwave disinfection, once a week, for 4 weeks. Group 2: Patients had the maxillary dentures submitted to microwave disinfection, three times a week, for 4 weeks. Occlusal contacts were recorded on five occasions: 30 days after denture insertion and before first disinfection (baseline or control group); 1 week after disinfection; 2 weeks after disinfection; 3 weeks after disinfection; 4 weeks after disinfection. Occlusal contacts were analyzed by T-Scan III. Intergroup analysis was performed using the Mann-Whitney test and intragroup analysis using the Friedman test with significance of 5%. RESULTS: The results showed no significant difference between groups during the periods. The data on parameters loss of denture adaptation or complaints showed that patients used their dentures regularly for eating and expressed comfort and satisfaction in all experimental periods. The evaluation of functional occlusion revealed that the distribution of the occlusal contacts remained unaltered after disinfection. CONCLUSION: Microwave disinfection protocols as studied in this report did not influence occlusal contacts of the complete dentures.

Susceptibility of multispecies biofilm to photodynamic therapy using Photodithazine®.

This in vitro study evaluated the effect of photodynamic therapy (PDT) on the multispecies biofilm of Candida albicans, Candida glabrata, and Streptococcus mutans. Standardized fungal and bacterial suspensions were cultivated appropriately for each species and inoculated in 96-well microtiter plates for mix-biofilm formation. After 48 h of incubation, the biofilms were submitted to PDT (P + L+) using Photodithazine® (PDZ) at 100, 150, 175, 200, or 250 mg/mL for 20 min and 37.5 J/cm(2) of light-emitting diode (LED) (660 nm). Additional samples were treated only with PDZ (P + L-) or LED (P-L+), or neither (control, P-L-). Afterwards, the biofilms were evaluated by quantification of colonies (CFU/mL), metabolic activity (XTT reduction assay), total biomass (crystal violet staining), and confocal scanning laser microscopy (CSLM). Data were analyzed by one-way ANOVA and Tukey tests (p < 0.05). Compared with the control, PDT promoted a significant reduction in colonies viability of the three species evaluated with 175 and 200 mg/mL of PDZ. PDT also significantly reduced the metabolic activity of the biofilms compared with the control, despite the PDZ concentration. However, no significant difference was found in the total biomass of samples submitted or not to PDT. For all analysis, no significant difference was verified among P-L-, P + L-, and P-L+. CSLM showed a visual increase of dead cells after PDT. PDT-mediated PDZ was effective in reducing the cell viability of multispecies biofilm.

In vitro evaluation of adherence of Candida albicans, Candida glabrata, and Streptococcus mutans to an acrylic resin modified by experimental coatings.

This study evaluated the effect of experimental coatings, containing zwitterion or hydrophilic monomers, on the adherence of Candida albicans, Candida glabrata, and Streptococcus mutans to an acrylic resin. Acrylic samples (smooth or rough surfaces) were left untreated (control) or coated with one of the following experimental coatings: 3-hydroxypropylmethacrylate (HP) or sulfobetaine methacrylate (S), at concentrations of 25, 30, or 35%. Half of the specimens were coated with saliva. The adhesion test was performed by incubating specimens in C. albicans, C. glabrata, and S. mutans suspensions at 37°C for 90 min. The number of adhered microorganisms was determined by metabolic activity (XTT) and by cell viability (CFU). All coated specimens exhibited lower absorbance and CFU values compared to control specimens. Saliva and roughness did not promote microorganism adherence. An XPS analysis confirmed the modification in the chemical composition of the coatings in the experimental samples. These experimental coatings significantly reduced the adherence of C. albicans, C. glabrata and S. mutans to acrylic resin.

Enzymatic activity profile of a Brazilian culture collection of Candida albicans isolated from diabetics and non-diabetics with oral candidiasis.

The secretion of hydrolytic enzymes is a fundamental virulence factor of Candida albicans to develop disease. The objective of this study was to characterise the virulence of 148 clinical isolates of C. albicans from oral candidiasis by assessing the expression of phospholipase (PL) and secreted aspartyl proteinase (SAP). Isolates were obtained from healthy subjects (HS) and diabetics (DOC) and non-diabetics with oral candidiasis (NDOC). An aliquot (5 µl) of each cell suspension was inoculated on PL and SAP agar plates and incubated. Enzymes secretion was detected by the formation of an opaque halo around the colonies and enzymatic activity (PZ) was determined by the ratio between colony diameter and colony diameter plus the halo zone. Statistical comparisons were made by a one-way anova followed by Tukey's post hoc test (α = 0.05). The clinical sources of C. albicans had significant effect (P < 0.001) on the PZ values of both enzymes. For PL, clinical isolates from NDOC and DOC had highest enzymatic activity than those from HS (P < 0.05), with no significant differences between them (P = 0.506). For SAP, C. albicans from NDOC showed the lower enzymatic activity (P < 0.001). There were no significant differences between isolates from HS and DOC (P = 0.7051). C. albicans isolates from NDOC and DOC patients showed an increased production of PL.

Candida albicans adherence to an acrylic resin modified by experimental photopolymerised coatings: an in vitro study.

PURPOSE: This study evaluated whether photopolymerised coatings containing zwitterion or hydrophilic monomers would reduce the adhesion of Candida albicans to an acrylic resin. MATERIALS AND METHODS: Disc-shaped samples (n = 468) were fabricated with rough or smooth surfaces. The samples did not receive any surface treatment (control) or were coated with one of the following experimental coatings (2-hydroxyethyl methacrylate - HE; 3-hydroxypropyl methacrylate - HP; and 2-trimethylammonium ethyl methacrylate chloride - T; and sulfobetaine methacrylate - S). The concentrations of the constituent monomers were 25, 30 or 35%. The water contact angles of the samples were measured, and half of the samples were exposed to saliva. The adherent yeast cells were counted after crystal violet staining. RESULTS: For the smooth samples, the groups S35, HP35 and HE35 showed significantly lower number of adhered Candida than control, in the absence of saliva. There were no significant differences among the experimental and control groups for the rough samples, but the saliva decreased the cell numbers for groups S25, S30 and HP30. The photoelectron spectroscopy analysis confirmed the changes in the chemical compositions of the experimental samples. CONCLUSIONS: The experimental photopolymerised coatings changed the chemical composition and decreased C. albicans adhesion in the groups S35, HP35 and HE35, suggesting that they should be further investigated.

In vitro adhesion of Candida glabrata to denture base acrylic resin modified by glow-discharge plasma treatment.

This study evaluated the potential of plasma treatments to modify the surface chemistry and hydrophobicity of a denture base acrylic resin to reduce the Candida glabrata adhesion. Specimens (n = 54) with smooth surfaces were made and divided into three groups (n = 18): control - non-treated; experimental groups - submitted to plasma treatment (Ar/50 W; AAt/130 W). The effects of these treatments on chemical composition and surface topography of the acrylic resin were evaluated. Surface free energy measurements (SFE) were performed after the treatments and after 48 h of immersion in water. For each group, half (n = 9) of the specimens were preconditionated with saliva before the adhesion assay. The number of adhered C. glabrata was evaluated by cell counting after crystal violet staining. The Ar/50 W and AAt/130 W treatments altered the chemistry composition, hydrophobicity and topography of acrylic surface. The Ar/50 W group showed significantly lower C. glabrata adherence than the control group, in the absence of saliva. After preconditioning with saliva, C. glabrata adherence in experimental and control groups did not differ significantly. There were significant changes in the SFE after immersion in water. The results demonstrated that Ar/50 W treated surfaces have potential for reducing C. glabrata adhesion to denture base resins and deserve further investigation, especially to tailor the parameters to prolong the increased wettability.

Photodynamic inactivation of microorganisms present on complete dentures. A clinical investigation. Photodynamic disinfection of complete dentures.

The aim of this study was to evaluate the effectiveness of photodynamic therapy (PDT) for the disinfection of complete dentures. Biofilm samples were collected from dentures of 60 denture users who were randomly divided into four experimental groups (n = 15 each): subjects whose maxillary dentures were sprayed with 50 and 100 mg/l of Photogem® suspension (groups P50S and P100S) and patients whose maxillary dentures were treated with 50 and 100 mg/l of Photogem® gel (groups P50G and P100G). Dentures with photosensitizers were left in the dark for 30 min (pre-irradiation time) and then irradiated with blue LED light at 37.5 J/cm(2) (26 min). Denture samples were taken with sterile cotton swab before (left side surfaces) and after (right side surfaces) PDT. All microbial material was diluted and plated on selective media for Candida spp., Staphylococcus mutans spp., streptococci and a non-selective media. After incubation (48 h/37°C), the number of colony-forming units (cfu/ml) was counted. Microorganisms grown on selective media were identified using biochemical methods before and after PDT. The data were submitted to McNemar and Kruskal-Wallis tests (α = 0.05). No growth after PDT was observed in 60, 53, 47, and 40% of dentures from P100G, P50G, P100S, and P50S groups, respectively. When evidence of microorganisms' growth was observed, PDT regimens eliminated over 90% of microorganisms on dentures. This clinical study showed that PDT was effective for disinfecting dentures.

Cytotoxicity of denture base and hard chairside reline materials: a systematic review.

STATEMENT OF PROBLEM: Adverse reactions to the materials used for the fabrication and reline of removable denture bases have been observed. PURPOSE: The purpose of this study was to systematically review the published literature on the cytotoxicity of denture base and hard reline materials. MATERIAL AND METHODS: MEDLINE via PubMed, Google Scholar, and Scopus databases for the period January 1979 to December 2009 were searched with the following key words: (biocompatibility OR cytotoxic* OR allergy OR "burning mouth" OR "cell culture techniques") AND ("acrylic resins" OR denture OR monomer OR relin* OR "denture liners"). The inclusion criteria included in vitro studies using either animal or human cells, in which the cytotoxicity of the denture base and hard chairside reline resins was tested. Studies of resilient lining materials and those that evaluated other parameters such as genotoxicity and mutagenicity were excluded. Articles published in the English language and in peer-reviewed journals focusing on the cytotoxicity of these materials were reviewed. RESULTS: A total of 1443 articles were identified through the search. From these, 20 studies were judged to meet the selection criteria and were included in the review. In the majority of the studies, continuous cell lines were exposed to eluates of specimens made from the materials, and mitochondrial activity was used to estimate cell viability. The tested acrylic resins were grouped according to 5 major categories: (1) heat-polymerized; (2) microwave-polymerized; (3) autopolymerizing; (4) light-polymerized; and (5) hard chairside reliners. CONCLUSIONS: This review provided some evidence that the heat-polymerized resins showed lower cytotoxic effects than autopolymerizing denture base acrylic resins and light or dual polymerized reline resins. However, because of the large number of variables in the reviewed literature, a definitive conclusion could not be drawn.

Surface roughness of denture base and reline materials after disinfection by immersion in chlorhexidine or microwave irradiation.

BACKGROUND: This study evaluated the effect of disinfection by immersion and microwave irradiation on the roughness of one denture base resin (Lucitone-L) and five relining materials, three hard (Tokuyama Rebase II-TR, New Truliner-NT, Ufigel Hard-UH) and two resilient (Trusoft-T, Sofreliner-S). METHODS: Fifty specimens were made and divided into groups: CL2 specimens were brushed with 4% chlorhexidine (1 min), immersed in the same solution (10 min) and immersed in water (3 min); MW2 specimens were immersed in water and microwave irradiated (650W; 6 min); CL2 and MW2 specimens were disinfected twice; CL7 and MW7 specimens were submitted to seven cycles using chlorhexidine or microwave irradiation, respectively; W specimens were not disinfected and remained in water (37°C; 7 days). RESULTS: Results were statistically analysed (p = 0.05) and revealed that, at baseline, the highest mean value was observed for T (p < 0.001). Material NT showed increase in roughness after the first (p = 0.003), second (p = 0.001), seventh (p = 0.000) cycles of microwave disinfection and after 7 days of immersion in water (p = 0.033). CONCLUSIONS: Resilient liner S presented significant increase in roughness after the second cycle of disinfection with chlorhexidine (p = 0.003). Material T exhibited significantly decreased roughness in group W (p = 0.010), while microwaving produced severe alterations on its surface.

Effect of thermocycling on the flexural and impact strength of urethane-based and high-impact denture base resins.

OBJECTIVE: Mechanical properties of the acrylic resins used for denture fabrication may be influenced by water and temperature. Thus, the aim of this study was to evaluate the effect of thermocycling on the flexural and impact strength of a high-impact (Lucitone 199) and a urethane-based denture material (Eclipse). MATERIALS AND METHODS: Flexural strength (64 × 10 × 3.3 mm) and impact strength (60 × 6 × 4 mm) specimens were made following the manufacturers' instructions and assigned to two groups (n = 10): control (C) - not thermocycled - and T - thermocycled (5000 cycles between 5 and 55°C). Specimens were submitted to three-point bending and Charpy impact tests. RESULTS: Flexural strength (MPa) and impact strength (kJ/m(2)) data were analysed with two-way anova (p = 0.05). The flexural strength of material Eclipse (C, 136.5; T, 130.7) was significantly higher than that of resin Lucitone 550 (C, 99.4; T, 90.1). Material Eclipse exhibited significantly higher impact strength (C, 6.9; T, 5.3) than the resin Lucitone 550 (C, 3.5; T, 3.0). For both materials, a significant decrease in flexural and impact strengths was observed when the specimens were thermocycled. CONCLUSION: Flexural and impact strengths were higher for Eclipse than for Lucitone 550, in both groups. Thermocycling decreased the flexural and impact strengths of Eclipse and Lucitone 550.

Weight loss and changes in surface roughness of denture base and reline materials after simulated toothbrushing in vitro.

OBJECTIVE: To evaluate the weight loss and the surface roughness of acrylic resins after simulated brushing tests. MATERIAL AND METHODS: Ten specimens of each material (Tokuyama Rebase II-TR, New Truliner-NT, Ufi Gel Hard-UH and Lucitone 550-L) were made. The wear loss (mg) by weight and the surface roughness (Ra µm) of each specimen was determined before and after brushing. The specimens were placed on the brushing machine and a total of 20,000 brushing cycles was performed. The results of weight loss and roughness values were submitted to the anova followed by the Tukey's test (p = 0.05). RESULTS: The mean weight loss of material L was statistically higher (p < 0.001) than that of the relines TR, UH and NT. No significant differences were found among the roughness values of resins TR, UH and L (p > 0.05). Only for L, toothbrushing increased the surface roughness. After toothbrushing, there was no significant difference between the roughness values of materials L and NT. The highest mean weight loss during the simulated toothbrushing tests was observed for L. Before the toothbrushing tests, the NT exhibited the highest mean roughness. CONCLUSION: Brushing resulted in increase in roughness only for resin L.

The effect of long-term disinfection procedures on hardness property of resin denture teeth.

OBJECTIVE: The aim of the study was to evaluate the effect of long-term disinfection procedures on the Vickers hardness (VHN) of acrylic resin denture teeth. MATERIAL AND METHODS: Five acrylic resin denture teeth (Vipi Dent Plus-V, Trilux-T, Biolux-B, Postaris-P and Artiplus-A) and one composite resin denture teeth (SR-Orthosit-O) were embedded in heat-polymerised acrylic resin within polyvinylchloride tubes. Specimens were stored in distilled water at 37°C for 48 h. Measurements of hardness were taken after the following disinfection procedures: immersion for 7 days in 4% chlorhexidine gluconate or in 1% sodium hypochlorite (CIm and HIm group, respectively) and seven daily cycles of microwave sterilisation at 650 W for 6 min (MwS group). In the WIm group, specimens were maintained in water during the time used to perform the disinfection procedures (7 days). Data were analysed with anova followed by the Bonferroni procedure (α = 0.01). RESULTS: Microwave disinfection decreased the hardness of all acrylic resin denture teeth (p < 0.001). Immersion for 7 days in 4% chlorhexidine gluconate or distilled water had significant effect on the hardness of the acrylic resin denture teeth A (p < 0.01), and 1% sodium hypochlorite on teeth T (p < 0.01). All disinfection procedures decrease the hardness of the composite resin denture teeth (p < 0.01). Teeth O exhibited the highest and teeth V the lowest hardness values in the control group (p < 0.01). CONCLUSIONS: Disinfection procedures changed the hardness of resin denture teeth.

Effect of long-term water immersion on the fracture toughness of denture base and reline resins.

PURPOSE: This study evaluated the fracture toughness (FT) of one denture base (Lucitone 550 - L) and four hard reline resins [Ufi Gel Hard (UH), Tokuyama Rebase II (TR), New Truliner (NT) and Kooliner (K)], and the effect of long-term water storage on this property. MATERIALS AND METHODS: Forty specimens (40 × 8 × 4 mm) of each material were made, and FT was assessed after polymerisation (control of reliners), after 48 ± 2 h in water at 37°C (control of denture base resin) and after storage in water at 37°C for 7, 90 or 180 days (all materials). Data (MPa.m(1/2) ) were analysed by two-way anova and Games-Howell test (p = 0.05). RESULTS: Resin L exhibited the highest FT mean values. After 180 days of storage, FT mean values of L (3.37), UH (1.53) and K (1.20) were higher than those of the other periods. FT mean values of NT decreased from control (1.63) to 7 days (1.30) and then remained constant. FT mean values of TR (1.13) were similar in all periods of analysis. CONCLUSION: The denture base resin L showed higher FT mean values than the reline resins. Long-term water storage increased the FT of L, UH and K, reduced the FT of NT and did not influence the FT of TR.

Effectiveness of chlorhexidine on the disinfection of complete dentures colonised with fluconazole-resistant Candida albicans: in vitro study.

This in vitro study evaluated different concentrations of chlorhexidine (CHX) solution on the disinfection of dentures colonised with a reference (ATCC 90028) and azole-resistant (R1, R2 e R3) strains of Candida albicans. Sterile dentures were individually inoculated with one of the strains and incubated at 37 °C for 24 h. Then, each denture was immersed in sterile saline (control) or CHX (2%, 1% or 0.2%) for 10 min. Samples of serial dilutions were spread on Agar Sabouraud Dextrose and incubated at 37 °C for 48 h. The colonies were counted and the values of log(cfu ml(-1)) were analysed by Kruskal-Wallis test (P < 0.05). Dentures immersed in CHX were incubated for 7 days. For all strains, the cfu ml(-1) values of 0.2% CHX were significantly higher than those of 2% and 1% CHX. There was no difference between the cfu ml(-1) values of 2% and 1% CHX. For dentures immersed in CHX, ATCC 90028 strain showed lower cfu ml(-1) values than R2 and R3 strains. For control dentures, cfu ml(-1) values of ATCC 90028 strain were higher than those of R strains. Immersion in 2% CHX resulted in the highest number of dentures without fungal growth after 7 days. For denture disinfection, 2% CHX was the most effective concentration, and R strains were less susceptible to disinfection. Chlorhexidine is effective in disinfection of dentures contaminated with azole-resistant C. albicans.

Effect of thermal cycling on microleakage between hard chairside relines and denture base acrylic resins.

OBJECTIVES: Microleakage is a pre-stage of debonding between hard chairside relines and denture base acrylic resins. Therefore, it is important to assess them with regard to the longevity of the relined denture. This study investigated the effect of thermal cycling on the microleakage at the interface of three hard chairside reline resins and three denture base resins. MATERIAL AND METHODS: Rectangular bars (12 mm × 3 mm × 3 mm) of Lucitone 550, Acron MC and QC 20 were made and relined with Kooliner, Tokuyama Rebase Fast II and Ufi Gel Hard, Lucitone 550, Acron MC and QC 20 resins. Specimens were divided into one control and two test groups (n=10). In specimens of the control group, the microleakage was performed after the reline procedure. In Test Group 1, the specimens were stored for 24 h in distilled water at room temperature and in Test Group 2; the specimens were thermal cycled from 5 to 55°C for 5000 cycles with a 30-s dwell time. Subsequently, all specimens were immersed in 50% silver nitrate solutions for 24h. All specimens were sectioned longitudinally into three fractions and the lateral sections were examined (n=20). Silver nitrate stain penetration was examined under a stereoscopic lens with ×30 magnification, and the images were captured. Leica Qwin image analysis software was used to determine microleakage at the interface of the materials. Data were analysed using the Kruskal-Wallis test at a 95% level of significance. RESULTS: For all cycles, there were no statistically significant differences between thermal cycled and non-thermal cycled groups (p>0.05). CONCLUSION: It can be concluded that thermal cycling had no effect on the microleakage.

Effect of microwave disinfection on the surface roughness of three denture base resins after tooth brushing.

OBJECTIVE: This study investigated the effect of microwave disinfection on the roughness of three heat-polymerised acrylic resins after tooth brushing. BACKGROUND: Microwave disinfection has been recommended to reduce cross-contamination. However, this procedure may also influence the physical and mechanical properties of acrylic resins. MATERIALS AND METHODS: Specimens (40 × 20 × 2 mm) of resins: Lucitone 550 (L), QC 20(QC) and Acron MC (A) were prepared and divided into four groups (n = 10): Control groups 1 (C1) and 2 (C2) - stored in water for 48 h or 7 days; Test groups 1 (MW2) and 2 (MW7) - stored in water for 48 h and disinfected (650 W for 6 min) daily for 2 or 7 days, respectively. After treatments, the specimens were placed in a tooth brushing machine at a rate of 60 reciprocal strokes per minute. The specimens were brushed with 20 000 strokes, which represent approximately 2 years of denture cleansing. The surface roughness (Ra) was evaluated before and after the tooth brushing. Data were analysed by two-way anova and Tukey Honestly Significant Difference (HSD) post hoc tests (α = 0.05). RESULTS: The data revealed significant changes between test groups for A and L resins. Comparison among resins revealed that for MW7, the roughness of A was significantly lower than that of L. After the seven microwave cycles, it could be seen that the roughness values of QC were significantly lower than those of L. CONCLUSIONS: The roughness of QC after brushing was not significantly affected by microwave disinfection. For A and L, seven microwave cycles resulted in increased roughness.

[The challenges of comprehensive care in a Psychosocial Care Center and the development of therapeutic projects]. / Os desafios da integralidade em um Centro de Atenção Psicossocial e a produção de projetos terapêuticos.

The object of this study is the development of therapeutic projects by the team working in a Psychosocial Care Center (CAPS III). It takes into consideration the creation and expansion process of the Brazilian public health system (SUS) and Psychiatric Reform. In this context, workers are challenged to develop care through an individual therapeutic project that considers the true needs and life context of the people involved. The objective of the study was to analyze and describe the strengths and weaknesses of a to develop the therapeutic projects based on the cartographic model and on the focal group technique. Participants were workers from a CAPS III center from Diadema, São Paulo. By analyzing the data collected through focal groups, the authors found, above all, a rupture between the night and day teams, and a lack of systematic space for conversation to develop and discuss on the therapeutic projects.

Effect of water storage on the shear strength and fatigue limit of the reline resin bond to denture base resins.

PURPOSE: This study evaluated the effect of water storage (WS) on the shear bond strength (SBS) and shear bond fatigue limit (SBFL) between denture base and reline resins. In addition, a possible correlation between SBS and SBFL was evaluated. MATERIALS AND METHODS: Two denture base (Lucitone 550-L and Acron MC-AC) and two reline resins (Ufi Gel Hard- UGH and Tokuso Rebase Fast-TR) were selected. Cylinders (20 x 20 mm) of each denture base resin were processed, and the reline resins were packed on the bonding surfaces using a split mold (3.5 x 5.0 mm). Specimens of each denture base-reline resin combination were subjected to shear forces (0.5 mm/min) until fracture. A staircase approach was used to determine the SBFL. Specimens were submitted to either 10,000 cycles (5.0 Hz) or until fracture. For both SBS and SBFL, specimens were tested after relining (control) and after 30 days of WS. Data (MPa) were analyzed with 2-way ANOVA and Tukey's tests (α = 0.05). To test for a possible correlation between the SBS and SBFL, a linear regression analysis was performed. RESULTS: WS significantly increased (p < 0.05) the SBS of AC-TR and AC-UGH and the SBFL of AC-TR, AC-UGH and LUGH. After WS, UGH produced higher (p < 0.05) SBS than TR, regardless of the denture base resin used. Regardless of the experimental groups and the denture base resins used, UGH produced higher (p < 0.05) SBFL than TR specimens. A strong positive linear correlation (r(2) = 0.949) was observed between the SBS and SBFL. CONCLUSION: Overall, UGH promoted the highest SBS and SBFL. WS increased the SBS and SBFL of the AC relined specimens. A positive correlation was observed between the two variables.

Effect of reline material and denture base surface treatment on the impact strength of a denture base acrylic resin.

OBJECTIVE: In this study, the effect of relining and surface treatment on the impact strength (IS) of a heat-polymerising denture base acrylic resin (Lucitone 550-L) was evaluated. MATERIALS AND METHODS: Rectangular bars of L were made (60 x 6 x 2 mm) and relined (2 mm) with the relining resins Ufi Gel Hard (UH) and Tokuso Rebase Fast (TR). Specimens relined with L and intact L, TR and UH specimens were also made (60 x 6 x 4 mm), for comparison. Before relining, the L surface was left untreated or wetted with methyl methacrylate monomer and/or the bonding agents (BA) supplied by manufacturers of the reline resins. V-notches were machined at the midpoint of the length of all specimens. The notches were made either across the width (Nw) or across the thickness of the specimens (Nth). The Charpy impact test was performed using a 0.5-J pendulum, which had been specially designed and constructed. Data were analysed separately for each notch position using one-way analysis of variance and Tukey honestly significant difference post-hoc test (p = 0.05). RESULTS: The IS of L was similar to that of L/L. For the Nw notch, treating the denture base L with TR BA and relining with TR reline material produced the highest IS. CONCLUSION: The IS of specimens made from heat polymerising acrylic resin Lucitone 550 was increased after relining using the hard chairside reline resin TR with its proprietary BA.