Measuring Rabbit (Oryctolagus cuniculus) Tooth Growth and Eruption by Fluorescence Markers and Bur Marks

Abstract

Rabbits (Oryctolagus cuniculus) and rodents possess continuously growing teeth, and dental problems are a major health issue in these species. Knowledge of tooth growth characteristics is required to adequately treat dental problems and advise owners concerning diets. Most research was performed using bur marks and measuring eruption and wear manually. However, this method cannot be applied to teeth less rostral than the first premolar; therefore, for evaluation of molars, other methods are needed. We evaluated the use of fluorochromes xylenol orange and calcein green to measure growth rates of rabbit teeth and compared this method to results obtained by manually measuring the distance between a bur mark and the gingival margin of the same tooth (eruption) and by measuring the distance between the bur mark and the apex of the same tooth on computed tomography scans (growth). Apical fluorochrome measurements correlated well with eruption and growth rates obtained with bur marks, whereas measurements coronal to the pulp cavity did not. Growth rates were approximately 1.9 mm/wk for maxillary and 2.2 mm/wk for mandibular incisors. Growth rates of premolars were 2.14+0.28 mm/wk in rabbits on a grass/rice hulls/sand pelleted diet and 0.93+0.18 mm/wk in rabbits on a hay diet. Growth of molars could only be assessed using the measurement in dentin on the wall of the pulp cavity, which does not account for the real growth. However, being similar to this measurement in premolars, one could hypothesize similar growth in molars as in premolars. We conclude that the application of fluorochrome staining can be used to measure tooth growth in teeth that are not accessible for bur marks or in animals that are too small to assess tooth eruption or growth by bur marks.

Dentin Growth after Direct Pulp Capping with the Different Fractions of Plasma Rich in Growth Factors (PRGF) vs. MTA: Experimental Study in Animal Model

“…Usually, the studied teeth are molars or incisors, the latter having the advantage of a better access to perform the perforation and place the bioactive molecules onto the pulp tissue. Note that rodent’s incisors continuously grow; in this they are very different from human teeth [ 13 ]. Despite this fact, rodent’s incisors have also been validated as a study model, useful for the evaluation of potential human dental pulp response [ 19 , 20 , 21 , 22 ].…”

“…Moreover, the fluorochromes have been conveniently used to determine dentin growth rates in rabbit incisors [ 13 , 23 ]. The fluorescence microscopic markers present the advantages of not being an invasive procedure and not causing toxicity [ 24 ].…”

“…Those results tend to establish that PC seem to have a limited action both in time and influence area, when used for VPT. The rabbit incisors, with a fast continuous growth (1.9 mm/wk for maxillary incisors and 2.2 mm/wk for mandibular incisors) [ 13 ], could present a limitation to evaluate the effect of PRGF in the dentinogenesis in a 28-day evaluation period; a shorter observation period could be indicated for this model.…”

“…In vivo markers were used to evaluate the mineralization process: 15 mg/kg tetracycline was injected to the rabbits, 24 h before the intervention, and 15 mg/kg of calcein the day before euthanasia, which was performed 28 days after the intervention. These markers were used afterwards to assess dentin growth by means of fluorescence microscopy [ 13 ].…”

Dose-related effects of extracorporeal shock waves on orthodontic tooth movement in rabbits

“…However, rodents possess long-crowned, continuously growing and open-rooted teeth 26 . Maxillary incisors of rabbits can grow up to approximately 1.9 mm per week depending on the type of food they are fed 27 . This physiological eruption of the incisors can cause the level and amount of force applied by the spring to change.…”