Observations of pulpotomy in rats using in vivo Micro-CT —The changes after treatment of formocresol and calcium hydroxide pulpotomies or CO 2 laser irradiation—

Abstract

In general, pulpotomy is evaluated by pathological examination of sacrificed animals at each observing stage. Not only lots of small animals have to devote itself to experimentation, but also the result of research is lacking about the serial observation of an individual experimental animal. The aim of this study was to compare the relative effectiveness of the calcium hydroxide, formocresol and CO 2 laser using the R_mCT ®. Twenty male Wistar rats, 8 weeks of age, were used and imaged in present study. They were serially observed using the R_mCT ® on days 0, 3, 10, 30, 50 after pulpotomy, followed pathohistological examination. The R_mCT ® images revealed that the pulp capping agents were partly absorbed and a hard tissue-like was observed immediately beneath it, especially in the CO 2 laser group. Pathohistological examination showed a hard tissue-like appearance and inflammatory cell infiltration. The R_mCT ® images agreed with pathohistological finding on the days 50 after pulpotomy. Our research suggested that the R_mCT ® has made it possible to scan serial imaging of small animals such as experimental rats under anesthesia. Since its higher resolution enables clear observation of the entire hand of the rat, it is possible not only to compare the effectiveness of each pulpotomy method, but also to serially observe a single experimental animal during the process post-pulpotomy healing, growth, and aging. This study answered well for the animal protective law that to use the least of animal to got the best result. animals at each observing stage. Not only lots of small animals have to devote itself to experimentation, but also the result of research is lacking about the serial observation of an individual experimental animal. Although there are some reports in literature describing the changes post treatment of formocresol and calcium hydroxide pulpotomies or laser irradiation on enamel, dentin, and pulp, relatively little histological information is available regarding the shot-and long-term change at the light and electron microscopic level 1-15). In order to study changes after pulpotomy, a long follow-up period with an individual animal is

Low‐energy laser irradiation accelerates the velocity of tooth movement via stimulation of the alveolar bone remodeling

“…However, it is determined using the sample after sacrifice, and temporal change of the same sample cannot be determined. In the present study, we used R_mCT ® that is a cone beam system, in which the X‐ray arms rotate 360° focusing on a sample, resulting in scanning the whole of rat jaw‐bone in only 17 s. These characteristics enabled reduction of exposure and the extent of anesthesia, and it is possible to scan the same sample temporally, since there is little harm to the experimental animals (37–40). The CT images were taken in vivo and the pixel size of this CT is 30 μ m. The absorption of X‐rays by the bone was observed by the resolution of the CT image.…”

Effect of CO2 laser irradiation on wound healing of exposed rat pulp

“…[17][18][19][27][28][29][30][31][32][33][34][35][36][37][38] When a living body is laser irradiated, both an irreversible reaction by a photothermal effect and a reversible reaction by a photoactive effect occur. The photothermal effect generally produces various morphological changes in the surface of soft tissue, such as vaporization, carbonization, hemocoagulation, and protein denaturation.…”

The formaldehyde inspiration by the child patient, dentist, and dental assistant during formocresol pulpotomy

“…This leads to inflammation even with a minor bacterial invasion, and in a significant number of patients, the lack of anti-inflammatory action leads to pulpectomy. In recent years, there has been research into highly biocompatible pulp capping materials and methods that are minimally irritating to pulp tissue, such as mineral trioxide aggregate 18,19) , ceramics 3) , calcium carbonate 20) , lasers 21) . FC pulpotomies in primary teeth are reported to achieve high rates of clinical success 1) .…”