Validation of a Portuguese version of the Groningen radiotherapy-induced xerostomia questionnaire.

BACKGROUND: The aim of this study was to validate and determine at pretest level the reliability of the Portuguese version of the Groningen radiotherapy-induced xerostomia questionnaire. MATERIAL AND METHODS: This study employed 37 head and neck cancer patients. Each patient signed an informed consent and responded to the Portuguese version of the questionnaire in the form of an interview. This was repeated again after 2 weeks. A standard single question provided a validity check. Data were analyzed using Cronbach's α to test its reliability and total and interitem correlation, and intraclass correlation to determine its internal consistency and test-retest reliability. Construct validity supported by objective measurements as salivary secretion was also investigated. Significance was set at .05. RESULTS: Cronbach's α was 0.91 and 0.89 for the first and second test administrations, respectively, which indicates that the internal consistency was excellent. The intraclass correlation coefficient value for the test-retest reliability was 0.70. The correlation between the total score of the questionnaire and standard single dry mouth question was 0.72 for the first round, indicating a good correlation. CONCLUSIONS: Demonstrating very good psychometric properties, the Portuguese version of the Groningen radiotherapy-induced xerostomia questionnaire is a valid tool and can be considered a reliable instrument to measure xerostomia in head and neck cancer patients.

Long term outcomes of biomaterial-mediated repair of focal cartilage defects in a large animal model.

The repair of focal cartilage defects remains one of the foremost issues in the field of orthopaedics. Chondral defects may arise from a variety of joint pathologies and left untreated, will likely progress to osteoarthritis. Current repair techniques, such as microfracture, result in short-term clinical improvements but have poor long-term outcomes. Emerging scaffold-based repair strategies have reported superior outcomes compared to microfracture and motivate the development of new biomaterials for this purpose. In this study, unique composite implants consisting of a base porous reinforcing component (woven poly(ε-caprolactone)) infiltrated with 1 of 2 hydrogels (self-assembling peptide or thermo-gelling hyaluronan) or bone marrow aspirate were evaluated. The objective was to evaluate cartilage repair with composite scaffold treatment compared to the current standard of care (microfracture) in a translationally relevant large animal model, the Yucatan minipig. While many cartilage-repair studies have shown some success in vivo, most are short term and not clinically relevant. Informed by promising 6-week findings, a 12-month study was carried out and those results are presented here. To aid in comparisons across platforms, several structural and functionally relevant outcome measures were performed. Despite positive early findings, the long-term results indicated less than optimal structural and mechanical results with respect to cartilage repair, with all treatment groups performing worse than the standard of care. This study is important in that it brings much needed attention to the importance of performing translationally relevant long-term studies in an appropriate animal model when developing new clinical cartilage repair approaches.

Prevalence of C-shaped canal morphology using cone beam computed tomography - a systematic review with meta-analysis.

BACKGROUND AND AIM: To perform a systematic review of anatomical studies using cone beam computed tomography (CBCT) to assess the influence of demographic factors (age, gender and geographic region) on the prevalence of C-shaped canal anatomy in maxillary molars, mandibular premolars and molars. DATA SOURCES: A search was conducted between May and August 2018 in four electronic databases and five peer-reviewed journals. The authors of included articles were also contacted for additional studies and the bibliographic references hand-searched. STUDY ELIGIBILITY CRITERIA, PARTICIPANTS AND INTERVENTIONS: The research protocol was previously registered in the International Prospective Register of Ongoing Systematic Reviews (CRD42018095201) and included defined inclusion/exclusion criteria. Prevalence studies on C-shaped canal anatomy in maxillary molars, mandibular premolars and molars were searched. STUDY APPRAISAL AND SYNTHESIS METHODS: The selected studies were submitted to full-text analysis and critical appraisal by two evaluators using the Joanna Briggs Institute Critical Appraisal tool. The final group of papers (n = 25) were pooled and forest plots with proportions and odds ratio with a 95% confidence interval performed. Meta-regression was undertaken to evaluate possible sources of heterogeneity and funnel plot visual analysis to assess publication bias. RESULTS: The included studies reported data on 25 445 teeth of 13 142 patients. A significant difference in the average prevalence proportion of C-shaped configuration was observed between mandibular first (0.3%; 0.1-0.6%) and second (12%; 10.3-13.7%) molars (P < 0.05). No significant difference in the prevalence of C-shaped configurations was observed comparing males (13.5%; 8.8-18.3%) and females (20.5%; 13.7-27.4%) in mandibular second molars (P > 0.05), although males were associated with significantly lower odds (0.573; 0.511-0.641) (P < 0.05). The pooled proportion of C-shaped anatomy in mandibular second molars in East Asian countries (39.6%; 36.0-43.1%) was significantly higher compared with other regions. LIMITATIONS: Because of the limited number of studies, no statistical analysis was performed for maxillary molars and mandibular premolars. CONCLUSION: Meta-analysis revealed that gender and geographic region may act as a confounding factor for the prevalence of C-shaped anatomy in mandibular second molars, whilst age did not influence the prevalence of C-shaped configurations in this tooth group. Knowing these preoperative factors would help to anticipate complex morphologies in clinics.

Root and root canal morphology of the permanent dentition in a Caucasian population: a cone-beam computed tomography study.

AIM: To investigate in vivo the number of roots, the configuration of the root canal system and the root canal splitting and merging levels in the permanent dentition of a Caucasian population. METHODOLOGY: A total of 11 892 teeth were inspected in cone-beam computed tomography examinations that were collected from a pre-existing database. The number of roots was identified, and canal configurations were classified according to Vertucci's classification and its supplemental configurations. In addition, the merging and separation positions along the length of the root canal were identified. The Z-test was used to analyse the differences between independent groups. A value of P < 0.05 was considered significant. RESULTS: The majority of tooth types had considerable variation in the number of roots and root canal configuration types. Radix entomolaris and paramolaris were rare occurrences. The mesiobuccal root of the maxillary first and second molars had two root canals in 71% and 44% of cases, respectively. Nearly 30% of the mandibular incisors had two root canals. Root canal merging and splitting appeared more often in mandibular teeth. Merging was more common in the middle third of the root canal in the maxillary teeth and in the middle and apical thirds in mandibular teeth. Root canal splitting did not exhibit a tendency, and their position along the length of the root canal varied from tooth to tooth. CONCLUSION: Clinicians must be aware that each tooth may display several types of root canal configuration. However, a greater variability in root canal configuration was found in maxillary second premolars and in the mesiobuccal roots of maxillary molars. Main root canal merging and splitting may also be expected to occur at any level of the root canal.

Fabrication of hierarchical micro-nanotopographies for cell attachment studies.

We report on the development of micro/nanofabrication processes to create hierarchical surface topographies that expand from 50 nm to microns in size on different materials. Three different approaches (named FIB1, FIB2, and EBL) that combine a variety of techniques such as photolithography, reactive ion etching, focused ion beam lithography, electron beam lithography, and soft lithography were developed, each one providing different advantages and disadvantages. The EBL approach was employed to fabricate substrates comprising channels with features between 200 nm and 10 µm in size on polymethylmethacrylate (PMMA), which were then used to investigate the independent or competitive effects of micro- and nanotopographies on cell adhesion and morphology. Rat mesenchymal stem cells (rMSCs) were cultured on four different substrates including 10 µm wide and 500 nm deep channels separated by 10 µm distances (MICRO), 200 nm wide and 100 nm deep nanochannels separated by 200 nm distances (NANO), their combination in parallel (PARAL), and in a perpendicular direction (PERP). Rat MSCs behaved differently on all tested substrates with a high degree of alignment (as measured by both number of aligned cells and average angle) on both NANO and MICRO. Furthermore, cells exhibited the highest level of alignment on PARAL, suggesting a synergetic effect of the two scales of topographies. On the other hand, cells on PERP exhibited the lowest alignment and a consistent change in morphology over time that seemed to be the result of interactions with both micro- and nanochannels positioned in the perpendicular direction, also suggesting a competitive effect of the topographies.

Translation, validation, and construct reliability of a Portuguese version of the Xerostomia Inventory.

OBJECTIVES: To generate and validate at pretest level a cross-culturally adapted Portuguese version of Xerostomia Inventory (XI), a 11-item questionnaire designed to measure specific xerostomia rating of patients complaints. METHODS: The original English version of the XI was translated into Portuguese following the guidelines for cross-cultural adaptation of health-related quality of life measures. Thirty patients with primary Sjögren syndrome were recruited for this study. The questionnaires were administered by trained and calibrated dental doctors to each patient. XI properties were examined including reliability, internal consistency, and test-retest reliability, using Cronbach's alpha, total and inter-item correlation, and intra-class correlation coefficients (ICC), respectively. Construct validity supported by objective measurements of xerostomia intra-oral signs and salivary secretion was investigated. Alpha was set at 0.05. Informed consents and local ethical committee clearance were obtained. RESULTS: Internal consistency and test-retest reliability were excellent (Cronbach's α=0.9; ICC range=0.79-0.94). Scatterplot interpolation and Pearson correlation coefficient suggested the presence of a strong, negative, and significant correlation between salivation and the XI scores indicating construct validity. CONCLUSION: The Portuguese version of the XI can be considered a reliable and valid instrument to measure patients' xerostomia symptoms.

Investigation of the protective suitability of a dental fluorinated varnish by means of X Ray fluorescence and Raman spectroscopy.

BACKGROUND AND AIM: Evaluating the protective effect in human enamel of a fluorinated varnish after enduring a citric acid erosive challenge. METHODS: An in vitro model was developed considering the intraoral environment, human saliva and acid erosive procedures. The evaluation of the enamel specimens was undertaken through the direct analysis of enamel by means of Raman spectroscopy and Energy Dispersive X Ray Fluorescence (EDXRF). Ten tooth specimens per group were analysed during three stages: 1- before treatment; 2- After varnish (treatment group) or toothpaste (control) application; 3- After citric acid cycle. Additionally, Particle Induced Gamma Ray emission (PIGE) was used to gauge the fluorine uptake by enamel after the application of the varnish (stage 2). Results were presented as mean and standard deviation with ANOVA and Tukey post hoc performed considering a significance level of 0.05. RESULTS: A significant (p < 0.05) higher Ca levels were detected in treatment group at stage 2 (37.4 ± 0.4 w/w%) and 3 (37.1 ± 0.1) when compared to the control group. After varnish application in treatment group, depolarization ratios were significant lower (p < 0.05) and anisotropy were significant higher (p < 0.05), however no differences were detected in FWHM. CONCLUSIONS: The use of a fluorinated dental varnish suggests a protective effect for human enamel against dental erosion demineralization process which was detectable in an in vitro model.

Evaluation of the effect of fluorinated tooth bleaching products using polarized Raman microscopy and particle induced gamma-ray emission.

In this in vitro study, the effect of the application of tooth bleaching products in human enamel was evaluated using polarized Raman microscopy, particle induced gamma-ray emission (PIGE) and Vickers Hardness test. Due to their acidic nature, teeth whitening products are associated with changes in enamel mineralization. Consequently, products have appeared in the market that promote the incorporation of fluorine in order to decrease the solubility of the hydroxyapatite in enamel and prevent demineralization. This way, four commercial products with different active principle concentrations: 16% carbamide peroxide (Opalescence PF® and VivaStyle®) or 6% hydrogen peroxide (Opalescence Go PF® and VivaStyle Paint On®) and presence or not of fluorine were compared. The information on the crystalline state of the enamel was provided by the determination of the depolarization ratio of the symmetric stretching band of phosphate (at 959 cm-1). Furthermore, the content and uptake of F was evaluated using PIGE in the two fluorinated products as well as in one negative control group. In order to evaluate the microhardness of enamel by means of Vickers test, another group of polished samples was prepared (using Opalescence PF®) and evaluated. Conversely to what could be expected, the obtained results determined a statistically significant decrease of depolarization ratio, leading to an increase of mineralization after the application of the bleaching products, except for VivaStyle®. For this group, no significant variation was obtained before-after treatment, most likely due to the acidity of the product (pH = 5.8). Additionally, an increase of concentration of F in the dental tissues was determined for the fluorinated products. On the other hand, enamel polishing, required for the application of the Vickers test, led to increased susceptibility to erosion, resulting in decreased hardness and an increased enamel depolarization ratio.

Effects of gustatory stimulants of salivary secretion on salivary pH and flow: a randomized controlled trial.

OBJECTIVES: To compare salivary pH changes and stimulation efficacy of two different gustatory stimulants of salivary secretion (GSSS). SETTING: Portuguese Dental Faculty Clinic. DESIGN: Double blind randomized controlled trial. SUBJECTS: One hundred and twenty volunteers were randomized to two intervention groups. Sample sized was calculated using an alpha error of 0.05 and a beta of 0.20. MATERIALS AND METHODS: Participants were randomly assigned to receive a new gustatory stimulant of secretory secretion containing a weaker malic acid, fluoride and xylitol or a traditionally citric acid-based one. Saliva collection was obtained by established methods at different times. The salivary pH of the samples was determined with a pH meter and a microelectrode. MAIN OUTCOME MEASURES: Salivary pH variations and counts of subjects with pH below 5.5 for over 1 min and stimulated salivary flow were the main outcome measures. RESULTS: Both GSSS significantly stimulated salivary output without significant differences between the two groups. The new gustatory stimulant of salivary secretion presented a risk reduction of 80 +/- 10.6% (95% CI) when compared with the traditional one. CONCLUSIONS: Gustatory stimulants of salivary secretion with fluoride, xylitol and lower acid content maintain similar salivary stimulation capacity while reducing significantly the dental erosion predictive potential.

Raman spectroscopy analysis of dental enamel treated with whitening product - Influence of saliva in the remineralization.

In this work we present the analysis of dental enamel treated with an over-the-counter whitening product, bought in e-commerce at a very low cost, used without medical supervision in an abusive manner, in order to evaluate its demineralization action. Moreover, we studied the influence of renewal or non-renewal of saliva solution in which the specimens were stored throughout the study. The Degree of Demineralization was determined through the evaluation of the PO43- symmetric stretching band (~959cm-1) in Raman spectra of the specimens in different days during the course of the study. Results showed that a maximum of demineralization occurred between days 27 and 34 of application. Titration of the whitening product revealed a content of hydrogen peroxide 170-fold higher than what is allowed in Europe, according with legislation. Despite this extreme concentration of hydrogen peroxide, the demineralization was not as great as could be expected suggesting an important role of the pH of the solution in this demineralization mechanism.

Clonal variability among oral Candida albicans assessed by allozyme electrophoresis analysis.

A total of 49 Candida albicans strains were isolated from the saliva of 11 healthy children in Piracicaba, Brazil and were analyzed according to their alloenzymatic patterns. Among eight loci assayed, seven were polymorphic and allowed to determine allelic and genotype frequencies, in order to establish the genetic variables for this fungal population. Some children showed just one genetic type, whereas other harbored two or more clones of such yeast, in a multiclonal manner of colonization by C. albicans.