Enhanced alveolar bone loss in a model of non‐invasive periodontitis in rice rats

Abstract

OBJECTIVE The rice rat (Oryzomys palustris) develops periodontitis-like lesions when fed a diet high in sucrose and casein (H-SC). We aimed to establish whether this model can accurately mimic the development of human periodontitis. MATERIALS AND METHODS For this purpose, 28 day-old rice rats (15/group) were assigned to standard (STD) or H-SC diets and sacrificed after 6, 12, and 18 wks. Jaws were processed for morphometric, histometric, histologic, histomorphometric, and microCT analyses. RESULTS We found a progressive increase in horizontal alveolar bone loss (ABL) with age in maxillae of rats fed the STD diet as determined by morphometry. The H-SC diet exacerbated horizontal ABL at the palatal surface at 12 and 18 wks. Furthermore, increased vertical ABL was detected in mandibles and maxillae of rats fed the H-SC diet for 12 and/or 18 wks by histometry and microCT. Remarkably, the H-SC diet significantly increased bone remodeling at the interproximal alveolar bone of mandibles from rats fed for 6 wks, but not in those fed for longer periods. CONCLUSIONS These findings indicate that the H-SC diet induced a transient increase in alveolar bone remodeling, which is followed by ABL characteristic of moderate periodontitis.

Evaluation of Alveolar Bone Mandibular of Rats Obese Induced at Monosodium Glutamate Undergoing Modified Duodenal-Jejunal Bypass Surgery

“…But the presence of small quantity of inflammatory cells was found in the underlying connective tissue and exocytosis of these cells into the junctional and sulcular epithelium in all the groups studied. Researchers report that the standard diet offered to rodents for a period from 6 to 18 weeks favors the accumulation of bacterial plaque around the teeth [31]. As a result, some inflammatory cells are attracted to the underlying connective tissue and migrate to the junctional epithelium.…”

Age-related periodontitis and alveolar bone loss in rice rats

“…Though this study (Aguirre et al, 2012a) also disclosed a trend for rice rats consuming a pelleted standard (STD) diet to develop tissue level PD, there are currently no long-term studies of PD in STD diet-fed rice rats because of the perceived requirement to feed a H-SC diet to induce PD in rice rats. The STD diet-fed rice rat may have potential as a pre-clinical model that, without dietary intervention, not only complements existing rat models of mild and moderate PD, but also evolves continuously into SP in a sufficiently-compressed timeframe to enable practical studies that address human SP.…”

“…We recently confirmed that rice rats consuming a pelleted H-SC diet develop PD, including worsening of both alveolar crest height (ACH) and horizontal (h) alveolar bone height (ABH) (Aguirre et al, 2012a). Though this study (Aguirre et al, 2012a) also disclosed a trend for rice rats consuming a pelleted standard (STD) diet to develop tissue level PD, there are currently no long-term studies of PD in STD diet-fed rice rats because of the perceived requirement to feed a H-SC diet to induce PD in rice rats.…”

“…Each, with a known initiation date and requirement for ongoing maintenance or injection/inoculation, causes development of either localized or generalized tissue level PD similar to moderate PD in humans and permits studies of both the induction phase itself, and of preventive or remedial treatments of 2–8 weeks duration. The rice rat ( Oryzomys palustris ), is now known to be susceptible to induction of progressive SP by feeding of a powdered diet high in sucrose and casein (H-SC) with no requirement for mechanical manipulation to initiate/maintain the condition (Gupta & Shaw, 1956; Ryder, 1980; Aguirre, Akhter, & Kimmel, 2012a). As in human PD itself and the other small animal PD models, marginal gingivitis is the initial pathologic finding (Leonard, 1979), followed by widespread plaque accumulation and gingival ulceration.…”

“…We report here an experiment that investigates three new topics: a) ACH and hABH from STD diet-fed rice rats that includes the first evaluation of their periodontal condition at ages 4 weeks, 52 weeks, and 80 weeks (Gupta & Shaw, 1956; Aguirre et al, 2012a; Gotcher & Jee, 1981); b) systemic metabolic condition of rice rats that consumed a H-SC diet for 26 weeks; and c) a method to reverse H-SC-diet-induced PD. We hypothesize that rice rats fed a: a) STD diet from weaning develop durable SP by age 30 weeks; b) H-SC diet from weaning develop SP more rapidly than STD diet rats; c) H-SC diet from weaning for 26 weeks have abnormal serum glucose, insulin, and cholesterol; and d) H-SC diet long enough from weaning to develop moderate PD and then switched to a STD diet, experience stabilization or healing of PD.…”