An in vitro study on the inhibition and ultrastructural alterations of Candida albicans biofilm by zinc oxide nanowires in a PMMA matrix.

OBJECTIVES: The purpose of this study was (i) to investigate whether nanocomposite poly(methyl-methacrylate)-zinc oxide nanowires (PMMA-ZnO-NWs) have C. albicans antibiofilm activity; (ii) to evaluate the interaction between components of the nanocomposites based on PMMA-ZnO-NWs by Raman spectroscopy; and (iii) to assess ultrastructural alterations. DESIGN: Sixty-eight rectangles (17 PMMA (control) and 51 PMMA-ZnO-NWs (250, 500, 1000 ppm ZnO nanowires) were fabricated. C. albicans ATCC 10231 and a C. albicans clinical strain were tested. Adherence, biofilm formation and ultrastructural alterations were assessed by transmission electron microscopy. Raman mapping images and spectra were analyzed using main component analysis. RESULTS: Nanocomposite PMMA-ZnO-NWs inhibited the formation of C. albicans biofilms 94% at 1000 ppm and 80% at 500 ppm against both C. albicans strains. PMMA-ZnO-NWs induced ultrastructural alterations, including cell wall damage and disorganization of the cytoplasmic membrane, resulting in cell lysis. Raman spectroscopy showed new vibrational modes (300-365-485-600 cm-1) for PMMA and ZnO-NW interactions. CONCLUSIONS: PMMA-ZnO-NWs inhibited C. albicans dose-dependent biofilm formation and led to changes in the structures and cell membrane. Raman spectroscopy showed chemical interactions between ZnO-NWs and PMMA, as suggested by the appearance of new bands at 301 and 485 cm-1.

Relationship Between Xerostomia and Hyposalivation in Senior Chilean People

ABSTRACT: Background: Hyposalivation is an objective decrease in salivary flow and it can produce xerostomia; which is a subjective sensation of dry mouth, common condition in senior population. Objectives: To identify the association between xerostomia and hyposalivation and its risk factors in people aged 60 years and older, and to investigate the association with medications, habits and other oral complications. Methods: 211 participants were included. Xerostomia data was collected using a validated Spanish-Xerostomia Inventory (XI-sp). Unstimulated whole-salivary flow rates were measured to detect hyposalivation. Results were analyzed using Chi-square, Fisher tests and multivariate logistic regression analysis. p <.05. Results: No significant association was detected between Xerostomia and Hyposalivation (p=.0666). Xerostomia 84.3%(p=.036) and hyposalivation 81.4%(p=.004) occur more frequently in women. A significant association was found between hyposalivation with the female gender (OR = 2.46, 95% confidence interval (CI): 1.19-5.11, p=0.015); denture stomatitis (OR=3.71, 95% CI:1.03-13.3, p=0.045) and atrophic glossitis (OR=3.72, 95% CI:1.78-8.1, p=0.001). Only female gender (OR=2.54; 95% CI:1.19-5.43, p=0.016) was significantly associated with xerostomia. Conclusions: No statistically significant association was found between hyposalivation and xerostomia. A significant association was found between oral candidiasis, denture stomatitis and the atrophic tongue with hyposalivation. Being woman was a risk factor for xerostomia and hyposalivation.

Antibacterial activity against Streptococcus mutans and diametrical tensile strength of an interim cement modified with zinc oxide nanoparticles and terpenes: An in vitro study.

STATEMENT OF PROBLEM: Interim restorations are occasionally left in the mouth for extended periods and are susceptible to bacterial infiltration. Thus, dental interim cements with antibacterial properties are required. PURPOSE: The purpose of this in vitro study was to determine in vitro antibacterial activity against Streptococcus mutans and to compare the diametrical tensile strength (DTSs) of dental interim cement modified with zinc oxide nanoparticles (ZnO-NPs) with that of cement modified with terpenes. MATERIAL AND METHODS: Antibacterial properties of ZnO-NPs, terpenes, and dental interim cement modified with ZnO-NPs and cement modified with terpenes against S mutans were tested according to minimum inhibitory concentration (MIC) and direct contact inhibition (DCI). Tensile strength levels were evaluated using DTS. Results were analyzed using the Kolmogorov-Smirnov, ANOVA, and Tamhane tests (α=.05). RESULTS: The MICs of ZnO-NPs and terpenes against S mutans were 61.94 µg/g and 0.25% v/v, respectively. The DCI assay under the cylinders of cement (area of contact with the agar surface) revealed significant bacterial growth inhibition on Temp-Bond NE specimens with ZnO-NPs at MIC of 495.2 µg/g (8× MIC) and with terpenes at MIC 0.999% v/v (4× MIC) (P<.05). The Temp-Bond NE cement cylinder (control group) showed the lowest DTS (1.05 ±0.27 MPa) of all other test groups. In the Zn-NPs group, the greatest increase occurred in the NP8 (8× MIC; 495.2 µg/g) group with a value of 1.50 ±0.23 MPa, a significant increase in DTS compared with the control and terpene groups (P<.05). In the terpene group, the highest increase corresponded to group T2 (2× MIC; 0.4995% v/v) with a value of 1.29 ±0.18 MPa. CONCLUSIONS: The addition of terpenes and ZnO-NPs to interim cement showed antibacterial activity when in contact with S. mutans ATCC 25175. Both terpenes and ZnO-NPs antimicrobial agents increased diametral tensile strength.

In Vitro Effectiveness of a Terpenic Denture Cleanser on Old Biofilm Surfaces.

PURPOSE: To assess the effects of terpenic denture cleanser on denture biofilm removal using scanning electron microscopy (SEM). MATERIALS AND METHODS: The internal surface biofilm of four maxillary dentures was elucidated with Caristop-revelador Dual Tone, and 40 blue-stained specimens (0.6 cm × 0.4 cm × 2 mm) were obtained. These specimens were randomly assigned to one of the following four groups of 10 specimens each: control, Eci Clean, Fitty Dent, and terpenic denture cleanser. The period of immersion in each solution was 12 hours. Biofilm removal was evaluated using SEM, and morphologically varying areas of the SEM images were quantified with Imaris software. The data were analyzed using Kolmogorov-Smirnov, t-tests, ANOVA, and Tamhane's tests (p = 0.05). RESULTS: Data revealed that terpenic denture cleanser removed significantly more biofilm than any other treatment examined in this study. The t-tests revealed significant differences in the clean area that resulted from the use of the terpenic cleanser compared with the clean area that resulted from the use of Eci Clean (p = 0.013). Fitty Dent was the least effective and left dirty acrylic resin. The average areas with few removed layers were 59.3%, 43.3%, and 9.5% in Fitty Dent, Eci Clean, and terpenic cleanser groups, respectively. Tamhane's tests indicated that the Eci Clean and Fitty Dent groups were significantly different from the 0.5% terpenic cleanser group (p = 0.008). CONCLUSION: The terpenic denture cleanser was effective in removing denture biofilm.

Effects of palatal augmentation prosthesis in oropharyngeal dysphagia in Chilean patients with tongue cancer: Cases report

ABSTRACT: Therapy of malignant neoplasms of the tongue or oropharynx may cause dysphagia. Dysphagia in patients has negative significant social and psychological consequences. The six cases reports describe the effect of palatal augmentation prosthesis (PAP) on the management of dysphagia in patients with oral-pharyngeal cancer and as consequence of its treatment. The study also assesses PAP's effects on the quality of life of such patients.

Mandibular Overdentures Retained by Two Mini-Implants: A Seven-Year Retention and Satisfaction Study.

PURPOSE: Patients with atrophic edentulous ridges generally have problems with retention, therapeutic satisfaction, and comfort with their complete dentures. An alternative treatment to assist in improving retention and stability involves the use of mini-implants. The aim of this study was to evaluate the retention of mandibular overdentures connected to two mini-implants and overall patient satisfaction with them. MATERIALS AND METHODS: Seven patients with atrophic mandibular ridges (Type 4D Misch classification), aged 62 to 74 years old were rehabilitated with complete dentures. In each patient, two mini-implants measuring 15 or 13 mm in length and 1.8 mm in diameter were placed. After 15 days, overdentures were connected to the mini-implants with O-ring attachments. In each patient, retention of the overdentures was measured, and a survey of therapeutic satisfaction before and after connection to the mini-implants was administered. Prosthesis retention was measured with a digital dynamometer at 1 month, 6 months, and 2, 3, 5, and 7 years after mini-implant placement. Patient satisfaction was assessed with a survey. Data were analyzed with Student's t-test (satisfaction survey) and the Friedman test (retention measurements and satisfaction survey). RESULTS: The initial retention values (0.34 to 0.63 N without mini-implants) varied significantly (p ≤ 0.050). These values were less than the subsequent measurements of 3.92 to 9.64 N, taken after placement of the mini-implants and connecting them to the dentures. Satisfaction was good to very good over the 7-year observation period. Mucosa and peri-implant bone showed no pathological changes. CONCLUSIONS: In this limited sample size clinical study the results indicated that after connecting mandibular overdentures to two mini-implants, patient satisfaction significantly increased and retention significantly improved during the 7-year observation period.

Evaluación de sobredentaduras mandibulares implanto-retenidas confeccionadas con técnica Rehabilitación Oral M/Prótesis, Facultad Odontología, Universidad de Concepción, en pacientes del Servicio Salud Bío-Bío / Evaluation of mandibular overdenture implant retained made with Oral Rehabilitation Prosthetic mention Technique from Faculty of Dentistry, University of Concepción, in patients Health Service Bío Bío

Los servicios asistenciales revelan interés por establecer protocolos de rehabilitación con sobredentaduras mandibulares retenidas a implantes, pero necesitan respaldo científico evaluado con instrumentos confiables. Objetivo: El objetivo de este estudio fue evaluar un modelo-protocolo de rehabilitación con sobredentaduras implanto retenidas para servicios públicos, por medio de test de rendimiento masticatorio, valores de retención y valoración de la satisfacción terapéutica obtenidos con las prótesis mandibulares implanto-retenidas. Materiales y métodos: Este trabajo fue realizado entre la Facultad de Odontología Universidad de Concepción (FAO-UDEC) y el Servicio de Salud Bío Bío (SS-BÍO-BÍO). Catorce pacientes fueron seleccionados, usuarios del SS-BÍO-BÍO, y recibieron sobredentaduras implanto-retenidas confeccionadas con protocolo del programa Rehabilitación Oral mención Prótesis (ROMPE. FAO-UDEC). Dos Implantes Neodent (3,75 × 11 y 13 mm) por paciente fueron instalados y conectados con carga temprana. Antes y después de instalar y conectar los implantes se evaluó: la satisfacción terapéutica con encuesta Programa ROMPE.FAO-UDEC, la retención con dinamómetro Force Gauge y el rendimiento masticatorio con test tamizado de maní. Los datos fueron procesados con programa SPSS 16.0 con test Kolmogorov-Smirnov, t-test para muestras relacionadas. Significación estadística p < 0,05. Resultados: La eficiencia masticatoria aumenta de forma significativa después de la conexión de los implantes. La satisfacción terapéutica con las prótesis y la resistencia a la tracción son altamente significativas posterior a la conexión de ellas. Conclusiones: Estos resultados son coincidentes con la gran mayoría de estudios publicados, y permiten sostener científicamente que el protocolo de confección de sobredentaduras ROMPE FAO-UDEC y SS-BÍO-BÍO es una alternativa confiable.

Health care services show interest in establishing rehabilitation protocols with mandibular overdentures retained on two implants, but they require scientific evidence evaluated with reliable instruments. Objective: To evaluate masticatory performance, retention and therapeutic satisfaction of patientswith a model rehabilitation protocol for implant-retained overdentures. Materials and methods: This study was conducted between the Faculty of Dentistry, University of Concepción (FAO UDEC) and Bío Bío Health Service(SS-Bío Bio). Fourteen patients, selected users of Bío Bío Health Service, Los Angeles, received implant-overdentures using a protocol of the Oral Rehabilitation Prosthesis Program (ROMPE FAO UDEC). Two Neodent™ implants (3.75 × 11 and 13 mm) were installed in each patient and connected with early loading. Before and after installing and connecting the implants, (0, 30 and 60 days), therapeutic satisfaction was assessed using the ROMPE FAO UDEC graduate program questionnaire. Retention was measured with a Force Gauge Dynamometer, and masticatory performance was quantified with a peanut screening test. Data were processed with SPSS 16.0 program and Kolmogorov-Smirnov test and t- test were used. Significance was set at P < .05. Results: Masticatory efficiency significantly increases after connectingthe implants. Therapeutic satisfaction with the prosthesis and the tensile strength are highly significant. Conclusions: These results coincide with the vast majority of published studies. It can be scientifically argued that the ROMPE FAO UDEC, SS Bío Bío overdenture protocol is a reliable alternative.

In vitro activity of terpenes against Candida albicans and ultrastructural alterations.

OBJECTIVE: The purpose of this study was to investigate the in vitro activity of terpene blends combined with tissue conditioner against Candida albicans and the effect on its morphology and sub-micro structure. STUDY DESIGN: The minimal inhibitory concentration (MIC) of terpenes, obtained from a by-product of kraft pulping, was determined using broth microdilution against C. albicans strains, and the activity of terpenes combined with Coe-Comfort tissue conditioner was assessed. Cell morphologic alterations were evaluated using scanning electronic microscopy and transmission electronic microscopy. Data was analyzed using Student's t test P < .05. RESULTS: The MIC of terpene blends fluctuated between 0.097% and 0.39% (v/v). Coe-Comfort tissue conditioner mixed with terpenes exhibited a total inhibition of C. albicans (P < .05). Terpenes induced ultrastructural alterations, even at the MIC value, including an increase in size, shape modification, cell wall damage with perforations, pronounced disconnection between cell wall and cytoplasm, and cytoplasmic vacuoles. CONCLUSIONS: Terpenes had pronounced effects against C. albicans alone and in combination with Coe-Comfort tissue conditioner, which mainly resulted in cell wall damage.

In vitro and in vivo activity of Melaleuca alternifolia mixed with tissue conditioner on Candida albicans.

OBJECTIVE: The aim of this study was to identify in vitro and in vivo activity of Melaleuca alternifolia oil mixed with different tissue conditioners on the Candida albicans strain. STUDY DESIGN: Microbiological tests were used to isolate Candida albicans from patients with denture stomatitis. The in vitro antifungal activity of Melaleuca alternifolia against Candida albicans was determined when it was applied directly and when it was mixed with tissue conditioners (Fitt, Lynal, Coe-Comfort). The responses of 27 denture stomatitis patients treated with Melaleuca alternifolia mixed with Coe-Comfort (n = 9), Nystatin mixed with Coe-Comfort (n = 9), and Coe-Comfort (Control Group, n = 9), were evaluated over a period of 12 days. RESULTS: In the in vitro study, Coe-Comfort or Fitt conditioners mixed with 1 mL, 20% (vol/vol) of Melaleuca alternifolia oil exhibited a total inhibition of Candida albicans. Patients treated with M. alternifolia mixed with Coe-Comfort showed a significant decrease in palatal inflammation compared with those treated with Coe Comfort (P = .001). In addition, a significant inhibition of C. albicans growth was observed with M. alternifolia mixed with Coe-Comfort compared with only Coe-Comfort (P = .000004). CONCLUSION: M. alternifolia oil mixed with Coe-Comfort tissue conditioner is effective in treating denture stomatitis.