Masticatory performances and maximum occlusal forces of immediate and conventional loaded two-implant supported overdentures retained by magnetic attachments: preliminary study of randomized controlled clinical trial

Background The appropriate loading protocol to improve masticatory performance (MP) is still unclear in elderly patients and two-implant overdentures (2-IODs) wearers. This study aimed to compare the long-term MP and maximum occlusal force of immediate loading (IL) and conventional loading (CL) of 2-IODs retained by magnetic attachments. Nineteen edentulous patients were randomly assigned to either an IL (n=10) or CL group (n = 9). In the IL group, the implant was loaded on the same day as insertion, whereas it was loaded 3 months after insertion in the CL group. Magnetic attachments were used to retain all overdentures to the implants. MP, measured by a piece of color-changeable chewing gum and a gummy jelly test, and maximum occlusal force, measured using an occlusal force measuring device, were assessed in both groups at baseline and at 3-, 4-, and 5-year follow-ups. Results No significant differences were observed in the MP and the maximum occlusal force between the IL and CL groups at any time point. However, a significantly higher MP was observed at the 3-year time point in the IL group (P = 0.036). The maximum occlusal force revealed a significant correlation with MP, both with the color-changeable chewing gum and gummy jelly at 5 years. Conclusion After long-term observation, no significant differences in MP and maximum occlusal force were observed between the IL and CL groups. However, compared to pre-implant insertion of the complete denture, the MP in the IL group significantly improved at 3 years. Furthermore, the maximum occlusal force was significantly correlated with MP at 5 years. Trial registration UMIN, UMIN000009889. Registered on 28 January 2013.

Higher Masticatory Performance and Higher Number of Chewing Strokes Increase Retronasal Aroma

Mastication is a physiological process whereby food is comminuted and mixed with saliva to form a swallowable bolus; it is also the initial process for retronasal aroma that is released from foods to receptors in the nose. However, the influence of mastication state on retronasal aroma is poorly understood. The purpose of this study was to investigate the relationship between aroma concentration and factors related to mastication state. The study design was an analytical observational study. Twelve male volunteers (age, 26.5 ± 2.7 years) were recruited and divided into five and seven participants in the low and high masticatory performance groups, respectively. The stimulated salivary flow rate was measured while participants chewed paraffin wax. First, an odor sensor was placed in the nostril, and the aroma concentration was measured over time as participants chewed an orange-flavored gummy jelly standardized for masticatory performance assessment until swallowing; chewing strokes were counted to determine swallowing thresholds. Next, participants were instructed to chew the gummy jelly for a certain number of strokes (i.e., 50 or 100% of swallowing thresholds, as well as 30 strokes) and expectorate the jelly without swallowing. The surface area of comminuted jelly at 30 chewing strokes was defined as masticatory performance. Maximum and slope of aroma concentration, surface area, number of chewing strokes, and stimulated salivary flow rate were compared between low and high masticatory performance groups. Statistical significance was set at α = 0.05. At 30 chewing strokes, the maximum aroma concentration and the slope were significantly greater in the high masticatory performance group than in the low masticatory performance group. There was a positive correlation between the maximum aroma concentration and the number of chewing strokes with aroma release in both groups. No significant correlation was found between the maximum aroma concentration and the stimulated salivary flow rate. However, multiple regression analysis (with aroma concentration as a dependent variable) showed that the increase in surface area, the number of chewing strokes, and the stimulated salivary flow rate were significant explanatory variables. The results suggested that retronasal aroma was influenced by mastication state and salivary flow rate during chewing.

Value Added Gummy Jelly from Palmyra Palm (Borassus flabellifer Linn.)

The palmyra palm (Borassus flabellifer Linn.) is a multipurpose tree. It is commonly found along the coasts of Africa, South Asia and Southeast Asia due to its strong tap root system’s ability to store a large volume of water and raise the water table level in the surrounding area. Several uses of this plant include beverages, food, medicine, fiber and timber. Unfortunately, due to the short shelf-life of palmyra palm fruit, more than 60% of the annual fruit yield is lost within 10 days of harvesting, and there is limited commercial use of ripe palm fruit. As a result, the physical properties, physicochemical properties, and proximate composition of value-added gummy jelly from palmyra palm were evaluated. The results showed that up to 26% (w/w) of fruit juice (prepared by mixing the mesocarp of ripe palmyra fruit with water (at a 1:1 w/w ratio) and then removing the insoluble pulp) can be added to the gummy jelly recipe with significant effects on textural and color characteristics, as well as changes in moisture, protein, carbohydrate and energy content.