Effect of different cleansers on the weight and ion release of removable partial denture: an in vitro study

OBJECTIVE: Removable partial dentures (RPD) require different hygiene care, and association of brushing and chemical cleansing is the most recommended to control biofilm formation. However, the effect of cleansers has not been evaluated in RPD metallic components. The aim of this study was to evaluate in vitro the effect of different denture cleansers on the weight and ion release of RPD. MATERIAL AND METHODS: Five specimens (12x3 mm metallic disc positioned in a 38x18x4 mm mould filled with resin), 7 cleanser agents [Periogard (PE), Cepacol (CE), Corega Tabs (CT), Medical Interporous (MI), Polident (PO), 0.05 percent sodium hypochlorite (NaOCl), and distilled water (DW) (control)] and 2 cobalt-chromium alloys [DeguDent (DD), and VeraPDI (VPDI)] were used for each experimental situation. One hundred and eighty immersions were performed and the weight was analyzed with a high precision analytic balance. Data were recorded before and after the immersions. The ion release was analyzed using mass spectrometry with inductively coupled plasma. Data were analyzed by two-way ANOVA and Tukey HSD post hoc test at 5 percent significance level. RESULTS: Statistical analysis showed that CT and MI had higher values of weight loss with higher change in VPDI alloy compared to DD. The solutions that caused more ion release were NaOCl and MI. CONCLUSIONS: It may be concluded that 0.05 percent NaOCl and Medical Interporous tablets are not suitable as auxiliary chemical solutions for RPD care.

Influence of the occlusal alteration in the mandible morphology of the gerbil / Influencia de la alteración oclusal en la morfología mandibular del jerbo

Considering the biomechanical aspects, many facts need to be understood on the mandible, to know which effects unilateral occlusal changes may cause on the stomatognathic system. The aim of this study was to analyze the malocclusion by unilateral teeth extraction on the mandible morphology in gerbil. We used 10 gerbils Meriones unguiculatus, young male, weighing around 50-60g, divided into two groups (n=5), an experimental group and control, which evaluated the two hemi-mandibles, with a total of 20 samples which were measured by digital pachymeter. The measures were taken: (1) length and (2) width of the mandible condyle and (3) body height in the region of mandibular 1st molar. Data from these measurements were analyzed using ANOVA and Mann-Whitney test. The results of this study showed a statistically significant difference in the three measures between experimental and control groups. The width of the mandible head (condyle) showed statistical difference between the ipsilateral and contralateral sides to teeth extraction. It was concluded that the mastication modification by unilateral teeth extraction caused an imbalance, promoting not only a modification in the craniofacial growth pattern, but also a harmful effect on the stomatognathic system of the gerbil used as an experimental model in this study.

Considerando los aspectos biomecánicos, muchos hechos deben ser entendidos sobre la mandíbula, haciendo necesario comprender cuales son los efectos que pueden causar una alteración oclusal unilateral en el sistema estomatognático. El objetivo de este estudio fue analizar la maloclusión por la extracción de los dientes unilaterales sobre la morfología de la mandíbula en el gerbo. Se utilizaron 10 gerbos Meriones unguiculatus, machos jóvenes, con un peso aproximado de 50-60g, divididos en dos grupos (n = 5), un grupo experimental y otro control, en los cuales se evaluaron las dos hemimandíbulas, totalizando 20 muestras que fueron medidas con un caliper digital. Las medidas tomadas fueron: (1) longitud y (2) ancho del cóndilo mandibular, y (3) la altura del cuerpo en la región de los primeros molares mandibulares. Los datos de estas mediciones se analizaron mediante la prueba ANOVA y Mann-Whitney. Los resultados de este estudio mostraron una diferencia estadísticamente significativa en las tres medidas entre los grupos experimental y control. El ancho de la cabeza de la mandíbula (cóndilo) mostró una diferencia estadística entre los lados ipsilaterales y contralaterales a la extracción dentaria. Se concluyó que existe una alteración unilateral de la masticación inducida por la extracción de dientes unilateralmente, causando un desequilibrio y promoviendo no sólo una modificación en el patrón de crecimiento craneofacial, sino también un efecto nocivo obre el sistema estomatognático del gerbo utilizado como modelo experimental en este estudio.