Angiogenesis/vasculogenesis and neurogenesis are critical for dentin and pulp regeneration. We have isolated pulp CD 31⁻ SP cells and CD 105^＋cells with multi-lineage differentiation potential and high migratory and proliferation potential. In models of mouse hindlimb ischemia, local transplantation of these pulp stem cells resulted in an increase in the blood flow including high density of capillary formation. The transplanted cells were in proximity of the newly formed vasculature without incorporating into vessels, and expressed several proangiogenic factors.These results suggested a potential utility of these subfractions of human dental pulp stem/progenitor cells to stimulate angiogenesis/vasculogenesis during tissue regeneration. The conditioned medium from these pulp stem cells demonstrated mitogenic and anti-apoptotic activities on endothelial cells,suggesting trophic actions on angiogenesis/vasculogenesis in the hindlimb ischemia. In the transplantation of these cells into the cerebral ischemic model neuronal progenitor cells migrated to the penumbra, followed by enhanced differentiation into neuron with high expression of neurotrophic factors.The functional outcome was improved.Autologous transplantation of the CD 31⁻ SP cells into an in vivo model of amputated pulp resulted in complete regeneration of pulp tissue with capillaries and neuronal processes. Furthermore,the transplantation of CD 31⁻ SP cells or CD 105^＋cells with SDF-1 into root canals after whole pulp removal of mature apicoectomized teeth resulted in complete regeneration of pulp replete with nerves and vasculature by day 14. The qualitative and quantitative protein and mRNA expression patterns of the regenerated pulp were similar to those of normal pulp.These results suggested a potential utility of these dental pulp stem/progenitor cells to stimulate pulp regeneration.

View full abstract

The term “special needs children” usually implies children who present with obvious developmental delay or who require assistance for disabilities that may be physical, mental, or psychological.However, considering the amount of assistance or effort that is necessary for completing dental treatment, it should be noted that not only the “disabled” or “sick” children but also “mistreated” children require special care. The demand of special care may be estimated by the degree of mistreatment(such as abuse) as well as the severity of disability.Based on the topics discussed in the lecture at the 48^th Annual Meeting of the Japanese Society of Pediatric Dentistry in 2010, this review summarizes 1) points to keep in mind while providing dental care for special needs children, and 2) the importance of partnerships with anesthesiologists, pediatricians, and therapists concerned with conductive education for disabled children.

View full abstract

In order to find important factors that relate to dental caries in the daily pediatric clinic, the relationship between dental caries and various factors that were collected at the time of the check-up visit after the series of dental caries treatment had been investigated. In this previous study child patients with deciduous dentition were surveyed and a significant relation with dental caries experience was found for factors like the amount of mutans streptococci (SM) in the dental plaque and saliva, the amount of dental plaque, frequency of food and drink intake, contents of meals, the amount of lactobacillus in saliva and the frequency of xylitol intake. The same survey was conducted in 29 children with mixed dentition in this study. Results were compared to former results in deciduous dentition,and the effects of eruption of the first permanent molar and the increase in age were investigated.The factor most related to dental caries experience in the mixed dentition was the amount of SM,the same as in the deciduous dentition. In addition to the amount of SM, the frequency of food and drink intake and brushing by the parents were significantly related to children's dental caries.Concerning fluoride application, increasing the kinds of fluoride application did not increase its caries preventative effect, the same as in the deciduous dentition study. Although the excretion of saliva and its buffering ability increased in proportion to age in the deciduous dentition, no relation was observed between these factors in the mixed dentition. No relation was observed between SM and the occurrence of dental caries in the first permanent molars of the mixed dentition. The fact that a significant relation was found only with “brushing by the parents” and “brushing in a lying position”was thought to be a useful data for recommending ages that require brushing by the parents.

View full abstract

There are two types of optical guide paths for CO2 laser, manipulation type and fiber type. However, few reports are found with respect to the effect of the guide path on the properties of the enamel surface after irradiation with a CO2 laser. We investigated the surface of bovine enamel after irradiation with a CO2 laser with the two types of guide paths.1.Transpiring hole area and the black diameter area increased with laser output with both types of optical guide paths. Those areas were two or three times wider in the fiber type than in the manipulation type.2.Irradiation energy was concentrated at one point on the surface in the manipulation type and dispersed at a few points in the fiber type.3.Transpiring hole area and the black diameter area were wider in pulse mode irradiation than in continuous mode.It was concluded that the manipulation mode is suitable for a pinpoint treatment and the fiber type for effective irradiation of a wide area.

View full abstract

The daily lifestyle of growing children may influence their masticatory function and physical ability.This study investigated the relationship between dental occlusion (occlusal contact area and occlusal force), physical ability (softball throw, standing jump, 25-meter run, one-leg standing), postural stability (sway distance, sway area), and foot arch among 225 Japanese preschool children, 3 to 5years of age.The upper and lower 25% of the occlusal force measurements were compared for physical ability and postural stability. Additionally, the upper 25% of the stable and the lower 25% of the unstable postural stability measurements in each age group were compared for dental occlusion and physical ability. Children who have a well-developed foot arch and an underdeveloped foot arch were compared for dental occlusion, physical ability and postural stability.Based on the analysis, the following findings were obtained :1)Dental occlusion, postural stability and physical activities were seen to improve with age.2)A tendency for better performance in postural stability was seen among all age groups in the upper occlusal force group. In the upper occlusal force group, the softball throw measurements in the 5-year-olds were significantly larger than that of the lower occlusal group.3)A tendency for good dental occlusion was seen among all age groups with stable postural stability.The stable postural stability groups showed a significantly larger occlusal force than the unstable groups in the 3-year-olds and 5-year-olds. The stable postural stability group showed a significantly large one-leg standing time than the unstable group in the 3-year-olds.4)3-year-olds with a well-developed foot arch (54.9%) were seen to have generally good dental occlusion and postural stability. 4- and 5-year-olds with a well-developed foot arch (85.7% and 86.7% respectively) were seen to have generally good physical ability, dental occlusion, and postural stability. In 5-year-olds, postural stability's sway distance was significantly smaller in the well-developed foot arch group than in the underdeveloped group.These findings suggest that in preschool children, growth and development, dental occlusion, physical ability, postural stability and foot arch seemed to be associated with each other.

View full abstract

The purpose of the present study was to examine the effect of neutral 2% and 0.05% NaF and acidic 2% and 0.05% APF solutions on Nickel (Ni) ion release and morphological change of the metal surface of two types of preformed metal crowns for the primary teeth in which metal crown A and metal crown B contain high and low levels of Nickel, respectively.Ni ion releases (measured as μm/cm²) from metal crown A and B were examined after immersion in each solution for 1, 3, 5 and 10 minutes.SEM observations of both crown metal surfaces, after immersion in four kinds of concentrations of fluoride solutions for 10 minutes, were made for the NaF and APF solutions, respectively.Both metal crowns showed greater Ni ion release in the 0.05% APF and 2% APF solutions than those in similar concentrations of NaF. Metal crown A showed more ion release than metal B.By SEM observation, both metal crown A and B immersed in the test solutions showed visible corrosive surface changes compared to before immersion, regardless of a different acid value. Moreover,more corrosive change of metal crown A was observed than that of metal crown B when immersed in the acid solutions of 2% and 0.05% of APF.Based on the amount of Ni ion release and SEM findings, it is clear that metal corrosive changes in preformed metal is affected by the contained Ni of the metal and the acidity of the immersion solution.

View full abstract