Microbial adhesion and biofilm formation by Candida albicans on 3D-printed denture base resins.

This study evaluated surface properties and adhesion/biofilm formation by Candida albicans on 3D printed denture base resins used in 3D printing. Disc-shaped specimens (15 mm x 3 mm) of two 3D-printed resins (NextDent Denture 3D+, NE, n = 64; and Cosmos Denture, CO, n = 64) and a heat-polymerized resin (Lucitone 550, LU, control, n = 64) were analyzed for surface roughness (Ra µm) and surface free energy (erg cm-2). Microbiologic assays (90-min adhesion and 48-h biofilm formation by C. albicans) were performed five times in triplicate, with the evaluation of the specimens' surface for: (i) colony forming units count (CFU/mL), (ii) cellular metabolism (XTT assay), and (iii) fluorescence and thickness of biofilm layers (confocal laser scanning microscopy). Data were analyzed using parametric and nonparametric tests (α = 0.05). LU presented higher surface roughness Ra (0.329±0.076 µm) than NE (0.295±0.056 µm) (p = 0.024), but both were similar to CO (0.315±0.058 µm) (p = 1.000 and p = 0.129, respectively). LU showed lower surface free energy (47.47±2.01 erg cm-2) than CO (49.61±1.88 erg cm-2) and NE (49.23±2.16 erg cm-2) (p<0.001 for both). The CO and NE resins showed greater cellular metabolism (p<0.001) and CO only, showed greater colonization (p = 0.015) by C. albicans than LU in the 90-min and 48-hour periods. It can be concluded that both 3D-printed denture base resins are more prone to colonization by C. albicans, and that their surface free energy may be more likely associated with that colonization than their surface roughness.

Effectiveness of disinfectant solutions associated or not with brushing on the biofilm control of a 3D printed-denture base resin.

BACKGROUND: The formation of biofilm on denture bases is a recurrent clinical problem that favors the development of denture stomatitis. The effectiveness of a hygiene protocol in a 3D-printed denture base resin is still uncertain. OBJECTIVE: To evaluate of the effectiveness of immersion, associated or not with brushing in a soap solution, on the biofilm control of a 3D-printed denture base resin. METHODOLOGY: Specimens of denture base resins [Cosmos Denture (COS) and Classico (CLA/control)] were contaminated in vitro with Candida albicans and immersed in sodium hypochlorite 0.25% (SH, alkaline peroxide) AP, chlorhexidine digluconate 2% (CD or PBS-Control), associated or not with brushing with 0.78% Lifebuoy soap. Roughness was evaluated before and after brushing and immersion. The effectiveness of the protocols was assessed by CFU/mL, cellular metabolism (XTT), scanning electron microscopy (SEM), and confocal scanning laser microscopy. Data were analyzed by T student, ANOVA/Welch, and Tukey/Gomes-Howell pos-hoc tests (α = 0.05). RESULTS: CLA showed greater roughness than COS. CFU/mL and XTT were higher in COS resin with a higher hyphae formation. Immersion in SH and CD eliminated CFU/mL and reduced XTT for both resins, associated or not with brushing. AP reduced CFU/mL only when associated with brushing. CONCLUSIONS: The biofilm on the 3D-printed resin was thicker and presumably more pathogenic, regardless of its smoother surface. Immersions in SH 0.25% and CD 2% are effective hygiene protocols for both resins, associated or not with brushing. AP should be recommended when associated with brushing with a Lifebuoy 0.78% solution.

Effectiveness of disinfectant solutions associated or not with brushing on the biofilm control of a 3D printed-denture base resin

Abstract The formation of biofilm on denture bases is a recurrent clinical problem that favors the development of denture stomatitis. The effectiveness of a hygiene protocol in a 3D-printed denture base resin is still uncertain. Objective To evaluate of the effectiveness of immersion, associated or not with brushing in a soap solution, on the biofilm control of a 3D-printed denture base resin. Methodology Specimens of denture base resins [Cosmos Denture (COS) and Classico (CLA/control)] were contaminated in vitro with Candida albicans and immersed in sodium hypochlorite 0.25% (SH, alkaline peroxide) AP, chlorhexidine digluconate 2% (CD or PBS-Control), associated or not with brushing with 0.78% Lifebuoy soap. Roughness was evaluated before and after brushing and immersion. The effectiveness of the protocols was assessed by CFU/mL, cellular metabolism (XTT), scanning electron microscopy (SEM), and confocal scanning laser microscopy. Data were analyzed by T student, ANOVA/Welch, and Tukey/Gomes-Howell pos-hoc tests (α = 0.05). Results CLA showed greater roughness than COS. CFU/mL and XTT were higher in COS resin with a higher hyphae formation. Immersion in SH and CD eliminated CFU/mL and reduced XTT for both resins, associated or not with brushing. AP reduced CFU/mL only when associated with brushing. Conclusions The biofilm on the 3D-printed resin was thicker and presumably more pathogenic, regardless of its smoother surface. Immersions in SH 0.25% and CD 2% are effective hygiene protocols for both resins, associated or not with brushing. AP should be recommended when associated with brushing with a Lifebuoy 0.78% solution.

Influence of the height of the mandibular ridge on the masticatory function during the functional adaptation with new complete dentures.

BACKGROUND: The period of functional adaptation to a new conventional complete denture embraces many transitory issues, and this period is directly related to the rehabilitation success. OBJECTIVE: This clinical trial evaluated the influence of the height of mandibular ridge on the masticatory function of complete denture (CD) wearers during the adaptation period. METHODOLOGY: A total of 28 individuals wearing new CDs (NR, n=14, normal mandibular ridges, 64±12.5 years, 9 female; RR, n=14, resorbed mandibular ridges, 69±6.8 years, 9 female) were assessed at 24 hours, 30 days, three months and six months after the insertion of the CDs for masticatory performance (MP, sieves method), satisfaction with CDs (questionnaire) and maximum occlusal bite force (MOBF) (gnatodynamometer). The classification of the mandibular ridges followed the Kapur index. Data of MP and MOBF were analyzed by two-way ANOVA and satisfaction with CDs was analyzed by Generalized Estimating Equations (GEE), α=.05. RESULTS: Participants with NR presented better masticatory performance (p=.000 - NR 30.25±9.93%, RR 12.41±7.17%), general satisfaction (p=.047), retention of mandibular denture (p=.001), chewing ability (p=.037), and comfort of wearing a mandibular denture (p=.000). Regardless of the mandibular ridge, MP (p=.000) was higher at three (21.26±12.07%) and six months (24.25±12.26%) in comparison to 24 hours (18.09±10.89%), the MOBF (p=.000) was higher at three months (78.50±6.49 N) compared to 24 hours (57.34±5.55 N) and 30 days (62.72±5.97 N), and the comfort of wearing a mandibular denture (p=.002) at three months (1.61 ± 0.07) was greater than 24 hours (1.29±0.10) and 30 days (1.36±10). CONCLUSIONS: The study suggests that the participants with NR have higher MP and satisfaction with their CD, regardless of the follow-up period after the insertion of the new CD. After subjects received the CD, a period of 3 months was necessary for achieving better achievement MOBF, MP, and self-perceived comfort with the mandibular denture, regardless of the height of the mandibular ridge.

Influence of adhesives usage in complete dentures during adaptation period varying the degree of resorption of mandibular ridges.

PURPOSE: This study evaluated the effect of the use of a powder-type adhesive on masticatory performance and oral health related quality of life (OHRQoL) in patients with normal and resorbed mandibular ridges during adaptation period with complete dentures. METHODS: Forty-two edentulous subjects (12 men, 30 women) were distributed in four groups: normal mandibular ridges with adhesive, n = 10; normal mandibular ridges without adhesive, n = 10; resorbed mandibular ridges with adhesive, n = 11; resorbed mandibular ridges without adhesive, n = 11. Masticatory performance was evaluated by sieving method and OHRQoL by Oral Health Impact Profile in Edentulous Adults (OHIP-EDENT) inventory at 30, 60 and 90 days after the insertion of new complete dentures. Data were analyzed using 2-way ANOVA test and Generalized Estimating Equations (GEEs), α = 0.05. RESULTS: The use of adhesive resulted in better masticatory performance at 30 (35.76 ± 12.63%) and 60 days (30.06 ± 10.54%) after the insertion of the dentures and did not influence on OHRQoL in participants with normal ridges during the adaptation period. The use of adhesive did not interfere on masticatory performance during adaptation period and had a negative effect on masticatory discomfort/disability subscale OHRQoL at 30-day period [5.2(3.6, 6.8)] for resorbed mandibular ridges with new complete dentures. CONCLUSIONS: The use of adhesive can improve masticatory performance of new complete dentures users with normal mandibular ridges in the initial adaptation period up to 60 days after insertion. For resorbed ridges subjects, the use of adhesive had a negative impact on masticatory discomfort/disability OHRQoL at 30 days after insertion.

Influence of the height of the mandibular ridge on the masticatory function during the functional adaptation with new complete dentures

Abstract The period of functional adaptation to a new conventional complete denture embraces many transitory issues, and this period is directly related to the rehabilitation success. Objective This clinical trial evaluated the influence of the height of mandibular ridge on the masticatory function of complete denture (CD) wearers during the adaptation period. Methodology A total of 28 individuals wearing new CDs (NR, n=14, normal mandibular ridges, 64±12.5 years, 9 female; RR, n=14, resorbed mandibular ridges, 69±6.8 years, 9 female) were assessed at 24 hours, 30 days, three months and six months after the insertion of the CDs for masticatory performance (MP, sieves method), satisfaction with CDs (questionnaire) and maximum occlusal bite force (MOBF) (gnatodynamometer). The classification of the mandibular ridges followed the Kapur index. Data of MP and MOBF were analyzed by two-way ANOVA and satisfaction with CDs was analyzed by Generalized Estimating Equations (GEE), α=.05. Results Participants with NR presented better masticatory performance (p=.000 - NR 30.25±9.93%, RR 12.41±7.17%), general satisfaction (p=.047), retention of mandibular denture (p=.001), chewing ability (p=.037), and comfort of wearing a mandibular denture (p=.000). Regardless of the mandibular ridge, MP (p=.000) was higher at three (21.26±12.07%) and six months (24.25±12.26%) in comparison to 24 hours (18.09±10.89%), the MOBF (p=.000) was higher at three months (78.50±6.49 N) compared to 24 hours (57.34±5.55 N) and 30 days (62.72±5.97 N), and the comfort of wearing a mandibular denture (p=.002) at three months (1.61 ± 0.07) was greater than 24 hours (1.29±0.10) and 30 days (1.36±10). Conclusions The study suggests that the participants with NR have higher MP and satisfaction with their CD, regardless of the follow-up period after the insertion of the new CD. After subjects received the CD, a period of 3 months was necessary for achieving better achievement MOBF, MP, and self-perceived comfort with the mandibular denture, regardless of the height of the mandibular ridge.

Masticatory function in complete denture wearers varying degree of mandibular bone resorption and occlusion concept: canine-guided occlusion versus bilateral balanced occlusion in a cross-over trial.

PURPOSE: The present cross-over study evaluated the masticatory function and maximum occlusal force of edentulous patients with complete dentures with bilateral balanced occlusion (BBO) and canine guidance (CG), with normal (NR) and resorbed mandibular ridges (RR). METHODS: Participants received new complete dentures and both occlusal concepts (BBO and CG) were applied for a period of 30 days each. The masticatory performance was evaluated with the sieving method; masticatory ability with a visual analog scale (VAS) and maximum occlusal force was assessed by means of a gnatodynamometer. Data were analyzed using repeated-measure ANOVA or Generalized Estimating Equations (GEEs), α = 0.05. RESULTS: Thirty women completed the trial. The height of mandibular ridge was significant for the masticatory performance (ANOVA, p < 0.001, NR = 46.35 ± 12.18%, RR = 30.39 ± 9.94%), regardless of the occlusion guidance. A significant effect of the occlusion guidance was observed for the maximum occlusal force (ANOVA, p = 0.021, CG = 31.99 ± 12.74 N, BBO = 28.37 ± 9.83 N). The occlusion guidance was not significant for the masticatory performance (ANOVA, p = 0.156) and the height of the mandibular ridge did not influence on the occlusal force (ANOVA, p = 0.060). The interaction of the factors (guidance × ridge) was not significant for masticatory performance (ANOVA, p = 0.184) and occlusal force (ANOVA, p = 0.236). The VAS scores showed a significant effect of the ridge on chewing of lettuce, resulting in greater ease (GEEs, p = 0.016) and chewing quality (GEE, p = 0.028) of this food for participants with resorbed ridges. Participants with CG reported greater ease of chewing fresh bread and beef, and expressed higher quality of chew raw carrot. Participants with CG and normal ridges exhibited the highest overall chewing ability, in comparison to BBO (Bonferroni, p < 0.05, CG = 91.9, BBO = 72.7). CONCLUSIONS: CG represents a viable alternative to the BBO in complete dentures with satisfactory clinical results related to the self-perception of chewing and occlusal force.

Effect of educational and self-care therapies on masticatory performance of women with painful temporomandibular disorder / Efeito das terapias educacionais e do autocuidado sobre o desempenho mastigatório de mulheres com disfunção temporomandibular dolorosa

Introduction: Temporomandibular disorders (TMD) can compromise masticatory performance due to the presence of pain, muscular dysfunction and limitation of mandibular movements. Substantial improvements in TMD pain can be achieved through therapeutic approaches including education and self-care. Objective: The aim of the present study was to investigate the impact of these treatment modalities in the masticatory performance of women with painful TMD. Material and method: Fifty-two women were randomly divided into three groups: Control Group (CG); Education Group (received education about TMD) (EG); Self-Care and Education Group (received education about TMD and instructions self-care therapies) (SEG). The education instructions about TMD and self-care therapies were transmitted through a video and printed illustrative material. The masticatory performance was evaluated through the sieves method ​​with natural tested foods in the evaluation periods: baseline evaluation, 30 days after and 60 days of follow-up. Data were analyzed and used with a one-way ANOVA parametric test for mean comparison of CG, EG and SEG groups (α = 0.05). Result: The masticatory performance of the participants was similar, irrespective of the proposed treatments, at baseline (p=.604), 30 days (p=.450) and 60 days (p=.669). Conclusions: The results indicated that treatment with educational and self-care therapies over a period of 60 days had no impact on the masticatory performance of women with painful TMD.

Introdução: As disfunções temporomandibulares (DTM) podem comprometer a capacidade mastigatória devido à presença de dor, disfunção muscular e limitação dos movimentos mandibulares. Melhorias substanciais da dor relacionada à DTM podem ser alcançadas através de abordagens terapêuticas incluindo a educação e os autocuidados. Objetivo: O objetivo do presente estudo foi investigar o impacto dessas modalidades de tratamento no desempenho mastigatório de mulheres com DTM dolorosa. Material e método: Cinquenta e duas mulheres foram divididas aleatoriamente em três grupos: Grupo Controle (CG); Grupo Educação (receberam instruções sobre DTM) (EG); Grupo de Autocuidado e Educação (receberam instruções sobre DTM e instruções sobre terapias de autocuidado) (SEG). As instruções de educação sobre DTM e terapias de autocuidado foram transmitidas através de vídeo e material ilustrativo impresso. O desempenho mastigatório foi avaliado através do método dos tamises com alimentos testes naturais nos períodos de avaliação: atendimento inicial, 30 dias após e ao fim de 60 dias de acompanhamento. Os dados obtidos, em porcentagem, foram analisados e foi utilizado o teste paramétrico ANOVA one-way para comparação das médias dos grupos CG, EG e SEG (α= 0,05). Resultado: O desempenho mastigatório dos participantes foi semelhante, independentemente dos tratamentos, no atendimento inicial (p=0,604), após 30 dias (p=0,450) e após 60 dias (p=0,669). Conclusão: Os resultados indicam que o tratamento com terapias educativas e de autocuidado durante um período de 60 dias não teve impacto no desempenho mastigatório das mulheres com DTM dolorosa.