Frequency of awake bruxism behaviour in orthodontic patients: Randomised clinical trial: Awake bruxism behaviour in orthodontic patients.

INTRODUCTION: The influence of aligners on the activity of the masticatory muscles is still controversial, especially regarding the behaviour associated with awake bruxism (AB). OBJECTIVE: To compare the frequency of AB behaviours between patients treated with aligners and fixed appliances. METHODS: The sample comprised 38 Class I patients (mean age 22.08 years), divided by simple randomisation into two groups: OA group; orthodontic aligners (n 19) and FA group; fixed appliance (n 19). The frequency of AB was investigated by the ecological momentary assessment using an online device (mentimeter), during 7 following days at different timepoints, before and after appliance placement and in the 2nd, 3rd, 4th and 6th months of orthodontic treatment. These variables were also evaluated: level of anxiety by the State-Trait Anxiety Inventory, stress by the Perceived Stress Scale, catastrophising related to pain and degree of hypervigilance by the Pain Vigilance and Awareness Questionnaire, and the presence of facial pain evaluated by the DC/TMD. RESULTS: There was no difference between groups in the frequency of AB behaviours, with mean of 53.5% for group OA and 51.3% for FA. The most frequent behaviour was slightly touching the teeth, and in FA group, there was a significant reduction in this behaviour soon after appliance placement. The groups did not differ concerning the degree of anxiety, stress, catastrophising, hypervigilance and facial pain. CONCLUSION: The orthodontic treatment performed with aligners or fixed appliances did not influence the frequency of AB during the 6 months of treatment. REGISTRY OF CLINICAL TRIALS: (REBEC): RBR-9zytwf.

Dimensional stability of alginate molds scanned at different storage times.

The aim of this study was to evaluate the precision and accuracy of molds made with four commercial brands of alginate scanned at different times using digital model analysis. Eighty molds of a standard Typodont were made using 4 types of alginate (CCC: Cavex Color Change; IA: Identic Alginate; HY5: Hydrogum 5 and JP: Jeltrate Plus). The molds were scanned at four times: immediately (T1), 24h (T2), 72h (T3) and 120h (T4) after molding. Measurements were taken in three dimensions: anteroposterior, transverse and vertical. Significant differences in dimensional changes were noted between the materials over time (p <0.05). Anteroposterior dimensional variation was noted between times, especially for IA and JP. For transverse and vertical variables, a difference was found between the groups, especially at 24 h, 72 h and 120 h. CCC presented significant dimensional shrinkage only at T120 (transverse). IA and JP presented larger dimensional distortions in the vertical measurements. The molding materials used were not dimensionally stable when evaluated after 120 hours of molding. However, such evidence suggests that alginates with longer storage time, such as Cavex Color Change, are more accurate than conventional alginates.

O objetivo do presente estudo foi avaliar a precisão e acurácia por meio de análise de modelos digitais de moldes digitalizados obtidos com quatro marcas comerciais de alginato em diferentes tempos. Oitenta moldes de um Typodont padrão foram obtidos utilizando 4 tipos de alginato (CCC: Cavex Color Change; IA: Identic Alginate; HY5: Hydrogum 5 e JP: Jeltrate Plus). Os moldes foram escaneados em quatro tempos: imediatamente (T1), 24h (T2), 72h (T3) e 120h (T4) após a moldagem. As medidas foram feitas em três dimensões: ântero-posterior, transversal e vertical. Diferenças significativas nas mudanças dimensionais foram observadas entre os materiais ao longo do tempo (p <0,05). Variação dimensional ântero-posterior foi observada entre os tempos, principalmente para IA e JP. Para as variáveis transversal e vertical houve diferença entre os grupos, principalmente em 24h, 72h e 120h. CCC apresentou contração dimensional significativa apenas em T120 (transversal). IA e JP apresentaram maiores distorções dimensionais na vertical. Os materiais de moldagem utilizados não foram dimensionalmente estáveis quando avaliados após 120 horas de moldagem. No entanto, tais evidências sugerem que os alginatos com maior tempo de armazenamento, como Cavex Color Change, são mais precisos do que os alginatos convencionais.

Dimensional stability of alginate molds scanned at different storage times / Estabilidade dimensional de moldes de alginato digitalizados em diferentes tempos de armazenamento

ABSTRACT The aim of this study was to evaluate the precision and accuracy of molds made with four commercial brands of alginate scanned at different times using digital model analysis. Eighty molds of a standard Typodont were made using 4 types of alginate (CCC: Cavex Color Change; IA: Identic Alginate; HY5: Hydrogum 5 and JP: Jeltrate Plus). The molds were scanned at four times: immediately (T1), 24h (T2), 72h (T3) and 120h (T4) after molding. Measurements were taken in three dimensions: anteroposterior, transverse and vertical. Significant differences in dimensional changes were noted between the materials over time (p <0.05). Anteroposterior dimensional variation was noted between times, especially for IA and JP. For transverse and vertical variables, a difference was found between the groups, especially at 24 h, 72 h and 120 h. CCC presented significant dimensional shrinkage only at T120 (transverse). IA and JP presented larger dimensional distortions in the vertical measurements. The molding materials used were not dimensionally stable when evaluated after 120 hours of molding. However, such evidence suggests that alginates with longer storage time, such as Cavex Color Change, are more accurate than conventional alginates.

RESUMO O objetivo do presente estudo foi avaliar a precisao e acurácia por meio de análise de modelos digitais de moldes digitalizados obtidos com quatro marcas comerciais de alginato em diferentes tempos. Oitenta moldes de um Typodont padrao foram obtidos utilizando 4 tipos de alginato (CCC: Cavex Color Change; IA: Identic Alginate; HY5: Hydrogum 5 e JP: Jeltrate Plus). Os moldes foram escaneados em quatro tempos: mediatamente (T1), 24h (T2), 72h (T3) e 120h (T4) após a moldagem. As medidas foram feitas em très dimensoes: ântero-posterior, transversal e vertical. Diferenças significativas nas mudanças dimensionais foram observadas entre os materiais ao longo do tempo (p <0,05). Variação dimensional ântero-posterior foi observada entre os tempos, principalmente para IA e JP. Para as variáveis transversal e vertical houve diferenga entre os grupos, principalmente em 24h, 72h e 120h. CCC apresentou contração dimensional significativa apenas em T120 (transversal). IA e JP apresentaram maiores distorções dimensionais na vertical. Os materiais de moldagem utilizados nao foram dimensionalmente estáveis quando avaliados após 120 horas de moldagem. No entanto, tais evidencias sugerem que os alginatos com maior tempo de armazenamento, como Cavex Color Change, sao mais precisos do que os alginatos convencionais.