Influence of brushing with an antiseptic soap solution on the surface and biological properties of a hard chairside reline resin

PURPOSE

To evaluate the influence of brushing with a specific antiseptic soap solution on the surface (roughness and hardness) and biological properties of a specific hard chairside reline resin.

METHODS

The hard chairside reline resin specimens were made and distributed to the following groups according to disinfectant solution: sodium hypochlorite 0.5% (SH), Lifebuoy solution 0.78%; experimental group (LS) and phosphate-buffered saline PBS to be submitted to the brushing cycle for 10 seconds. The roughness and hardness were assessed before and after the cycle. For the biological properties, the colony-forming unit and Alamar Blue assays were performed. For all the properties evaluated the sample size consisted of nine specimens. The data were submitted to two-factor ANOVA (surface properties) and one-way ANOVA (biological properties) and Tukey's post-test with a significance level of 5% (α= 0.05).

RESULTS

The Lifebuoy group did not present a statistical difference (P> 0.05) in relation to the other groups for the evaluated surface properties. Furthermore, the Lifebuoy solution showed a statistically significant difference (P> 0.05) in relation to the negative control in the reduction of biofilm on the resin and no significant difference (P> 0.05) was observed when compared to the positive control group. Thus, it was concluded that brushing with the Lifebuoy soap solution did not interfere with the surface properties of the hard chairside reline resin, and was able to reduce the biofilm of C. albicans.

CLINICAL SIGNIFICANCE

Disinfectant liquid soap can be used for brushing of relined removable dentures as a simple, low-cost, and effective method for removing the biofilm.

Influence of brushing with antiseptic soap solution on the surface and biological properties of an acrylic denture base resin

PURPOSE

To evaluate the influence of brushing with specific antiseptic soap solution on the surface (roughness, hardness, and color stability) and biological properties of a specific heat-polymerized denture base resin.

METHODS

189 denture base acrylic resin specimens (10 mm x 1.2 mm) were made and distributed into three groups: sodium hypochlorite 0.5% (SH), Lifebuoy solution 0.78% (LS) and phosphate-buffered saline (PBS) and were submitted to the brushing cycle for 10 seconds. For each property assessed the sample size was composed of nine specimens. Roughness, hardness, and color stability were assessed before and after the cycle. For the biological properties (biofilm formation and reduction capacity) the colony forming unit and Alamar Blue assays were performed. For this, the specimens were placed separately in a 24-well plate with medium containing C. albicans. The plate was incubated for 48 hours for the formation of mature biofilm. The data were submitted to two-factor ANOVA (roughness and hardness) and one-way ANOVA (color stability and biological properties) and Tukey's post-test (α= 0.05).

RESULTS

The Lifebuoy group did not present a statistical difference (P> 0.05) in relation to the other groups for the evaluated surface properties (roughness, hardness, and color stability). Also, from the colony-formation unit and Alamar Blue assays, there was no statistical difference (P> 0.05) between the groups. Regarding biofilm reduction capacity formed on the samples, the results obtained from the count of colony forming units (CFU/mL) showed a reduction of approximately 1.3 logs in the number of CFU/mL in the Lifebuoy group (µ = 4.78 log¹º) compared to the negative control group (µ = 6.02 log¹º) (P< 0.05). When evaluating the cellular metabolism of C. albicans cells, the experimental group did not show any statistical difference compared to controls (P> 0.05). Brushing with Lifebuoy soap solution did not alter the surface properties of the acrylic resin, and reduced the C. albicans biofilm.

CLINICAL SIGNIFICANCE

Brushing removable partial or total dentures can be performed using Lifebuoy liquid disinfectant soap, as a simple, low-cost, and effective method for removing biofilm.

Biological and physical properties of a reline acrylic resin after immersion in liquid antiseptic soaps

PURPOSE

To evaluate some biological (Candida albicans biofilm formation and cytotoxicity) and mechanical (roughness and hardness) properties of a hard reline acrylic resin after immersion in liquid disinfectant soaps.

METHODS

Reline samples were made (14 mm in diameter and 1.2 mm in thickness) and immersed in different disinfectant solutions: DW: distilled water at 37°C (control group); DS: Dettol liquid soap; and LS: Lifebuoy liquid soap. After immersion in the different groups, the properties of C. albicans biofilm formation, cytotoxicity, hardness, and roughness were evaluated. Each sample was immersed in the disinfectant solutions for 8 hours for microbiological testing and for 0, 7, 14, 21, and 28 days, with daily immersion cycles, for cytotoxicity and mechanical testing. Data were tabulated and analyzed by Shapiro-Wilk and Levene statistical tests. Based on these results, the appropriate tests for finding statistically significant differences were applied (α= 0.05).

RESULTS

There was a reduction of roughness after immersion of the samples in DS for 21 days (P= 0.0001) and LS for 28 days (P= 0.0218). Hardness values significantly increased after storage of samples in solutions (0.0007≥ P≥ 0.0076), especially considering the longer period of immersion (28 days). The viability and metabolic activity of the biofilm formed on the hard reline samples were significantly reduced (P< 0.05) after soaking in Lifebuoy liquid soap in relation to DW. In addition, the samples immersed in the different solutions were not cytotoxic, as they inhibited less than 25% in relation to the control group (100% of cell viability).

CLINICAL SIGNIFICANCE

This study showed that, in general, immersion in liquid disinfectant soaps had no adverse effect on the physical properties of the hard reline acrylic resin evaluated. In addition, Lifebuoy liquid soap reduced the biofilm formed on the samples and the solutions did not affect the cytotoxicity of the material. Disinfectant liquid soaps could be an alternative method for disinfection of relined dentures.

Biological and physicochemical implications of the aging process on titanium and zirconia implant material surfaces

STATEMENT OF PROBLEM

Changes in physicochemical properties because of implant material aging and natural deterioration in the oral environment can facilitate microbial colonization and disturb the soft-tissue seal between the implant surfaces.

PURPOSE

The purpose of this in vitro study was to investigate the effect of aging time on the physicochemical profile of titanium (Ti) and zirconia (ZrO₂) implant materials. Further microbiology and cell analyses were used to provide insights into the physicochemical implications of biological behavior.

MATERIAL AND METHODS

Disk-shaped specimens of Ti and ZrO₂ were submitted to roughness, morphology, and surface free energy (SFE) analyses before nonaging (NA) and after the aging process (A). To simulate natural aging, disks were subjected to low-temperature degradation (LTD) by using an autoclave at 134 ºC and 0.2 MPa pressure for 20 hours. The biological activities of the Ti and ZrO₂ surfaces were determined by analyzing Candida albicans (C. albicans) biofilms and human gingival fibroblast (HGF) cell proliferation. For the microbiology assays, a variance analysis method (ANOVA) was used with the Tukey post hoc test. For the evaluation of cellular proliferation, the Kruskal-Wallis test followed by Dunn multiple comparisons were used.

RESULTS

Ti nonaging (TNA) and ZrO₂ nonaging (ZNA) disks displayed hydrophilic and lipophilic properties, and this effect was sustained after the aging process. Low-temperature degradation resulted in a modest change in intermolecular interaction, with 1.06-fold for TA and 1.10-fold for ZA. No difference in biofilm formation was observed between NA and A disks of the same material. After 48 hours, the viability of the attached HGF cells was very similar to that in the NA and A groups, regardless of the tested material.

CONCLUSION

The changes in the physicochemical properties of Ti and ZrO₂ induced by the aging process do not interfere with C. albicans biofilm formation and HGF cell attachment, even after long-term exposure.

Effectiveness of chemical disinfection on biofilms of relined dentures: A randomized clinical trial

PURPOSE

To evaluate the effect of disinfection with sodium perborate or chlorhexidine (when combined with brushing) on the removal of biofilm in relined dentures.

METHODS

Swabs were collected 48 hours after the relining procedure and at the follow-up time intervals of 7, 15, 30, 90, and 180 days. The dentures' surface roughness was measured at the same times. 45 subjects were randomly divided into three groups of 15 subjects each. The control group brushed with coconut soap and a soft toothbrush. The sodium perborate group followed the same procedure and also disinfected with sodium perborate solution for 5 minutes per day. The chlorhexidine group followed the control group procedure and disinfected with 2% chlorhexidine digluconate solution for 5 minutes per day. The number of colony forming units and the surface roughness were evaluated statistically by 2-way repeated-measure ANOVA (α = 0.05).

RESULTS

The control group dentures exhibited similar levels of microbial cells throughout the experiment. However, after 15 days, no microbial growth was observed on the dentures for which either disinfection agent was used. There were no statistically significant differences in superficial roughness between the groups (P = 0.298). The disinfection agents used, combined with brushing, were able to remove the relined dentures' biofilm after 15 days of disinfection. Roughness was not a predominant factor in CFU reduction.

Colour stability of acrylic resin denture teeth after immersion in different beverages

The colour stability of acrylic resin denture teeth in beverages was investigated. A spectrophotometer measured the colour (CIE-L*a*b* system) of all specimens after storage in distilled water/for 24 h at 37 degrees C (T0). Specimens were then immersed in various beverages. After 15 days (T1) and 30 days (T2), for each material, the mean deltaE values were calculated and compared by two-way ANOVA and Tukey intervals (alpha = 0.05). In the deltaT0T1 period, specimens stored in red wine were significantly discoloured, compared to distilled water (P = 0.003). There was no difference between immersion solutions in deltaET0T2 (P = 0.772) and in deltaET1T2 (P = 0.058), and no difference between materials in all immersion periods.

Failures in the rehabilitation treatment with removable partial dentures

BACKGROUND

Despite being functional and having aesthetic benefits, the acceptance of patients regarding the use of removable partial dentures (RPDs) has been low. In part, this is due to the deleterious effects that causes discomfort to the patient. Success depends not only on the care expended by the patient, including daily care and oral hygiene, but also on common goals set by their professional and clinical staff, aiming beyond aesthetics, to incorporate issues of functionality and the well-being of patients.

METHODS AND RESULTS

For rehabilitation treatment with RPDs to reach the desired level of success without damaging the support structure, all the steps (diagnose, cavity preparation, adaptation of the metal structures, functional of distal extension and posterior follow-up) in the rehabilitative treatment should be carefully developed. A literature review was carried out, searching through MEDLINE (PubMed) articles published between 1965 and December 2012 including clinical trials and reviews about the use of RPDs.

CONCLUSIONS

This study describes factors that lead to failures and complications in oral rehabilitation through the use of RPDs and suggests possible solutions.

Peel bond strength of resilient liner modified by the addition of antimicrobial agents to denture base acrylic resin

In order to prolong the clinical longevity of resilient denture relining materials and reduce plaque accumulation, incorporation of antimicrobial agents into these materials has been proposed. However, this addition may affect their properties.

Impact strength of denture base and reline acrylic resins: An in vitro study

This study evaluated the impact strength of a denture base resin (Lucitone 550-L) and four reline resins (Tokuyama Rebase II-T; Ufi Gel Hard-U; New Truliner-NT, and Kooliner-K), both intact and in a reline combination (L/L, L/T, L/U, L/NT, and L/K). For each group (n = 20), half of the specimens were thermocycled before testing. Charpy tests were performed, and the impact strengths were calculated. Data were analyzed by two-way analyses of variance and Tukey's test (p = 0.05). For the intact groups, mean impact strength values for L (1.65 and 1.50) were significantly higher than those of the reline resins (0.38-1.17). For the relined groups, the highest mean impact strength values were produced by L/T (5.76 and 5.12), L/NT (6.20 and 6.03), and L/K (5.60 and 5.31) and the lowest by L/U (0.76 and 0.78). There were no significant differences between L and L/L. Thermocycling reduced the impact strength of T (from 0.73 to 0.38) and L/L (from 1.82 to 1.56).

Clinical evaluation of abutment teeth of removable partial denture by means of the Periotest method

Prosthodontics should be one of the means of establishing conditions for the maintenance of periodontal health. The forces applied to the abutment teeth and their effects are very important considerations in the design and construction of the removable partial dentures. This 6-month follow-up clinical study evaluated the degree of mobility of abutment teeth of distal extension and tooth supported removable partial dentures by using Periotest. Two types of clasp design were selected for evaluation. In cases with unilateral and bilateral distal-extension, a clasp design including a T clasp of Roach retentive arm, a rigid reciprocal arm and a mesial rest were used. For the abutments of tooth-supported removable partial dentures, a second clasp design with a cast circumferential buccal retentive arm, a rigid reciprocal clasp arm and a rest adjacent to the edentulous ridges was selected. A total of 68 abutment teeth was analysed. Periotest values were made at the time of denture placement (control) and at 1, 3 and 6 months after the denture placement. The statistical analysis was performed using Friedman test. All analysis was performed at a 0.05 level of significance. The results revelled that no significant changes in tooth mobility were observed during the 6-months follow-up (P > 0.05). In conclusion, our findings suggest that adequate oral hygiene instructions, careful prosthetic treatment planning and regular recall appointments play an important role in preventing changes in abutment tooth mobility caused by removable partial denture placement.