Laser-induced alveolar bone changes during orthodontic movement: a histological study on rodents

OBJECTIVE

The aim of this study was to assess by light microscopy changes in alveolar bone during orthodontic movement in rats.

BACKGROUND

Orthodontic movement causes both removal and deposition of bone tissue. The use of laser phototherapy (LPT) is considered an enhancement factor for bone repair.

METHODS

Thirty Wistar rats were divided into two groups (n = 15) and subdivided according to animal death (7,13, and 19 days). Half of the animals in each group were treated with LPT during orthodontic movement. After animal death, specimens were processed and underwent histological and semi-quantitative analyses (HE and Sirius red).

RESULTS

LPT-irradiated specimens showed significantly higher numbers of osteoclasts when compared with controls at both 7 (p = 0.015) and 19 (p = 0.007) days, as well as significant increases in the number of osteoblasts (p = 0.015) between days 7 and 13. The amount of collagen matrix was significantly reduced between days 7 and 13 at both pressure and tension sites in controls (p = 0.015) but not in LPT-treated animals. LPT-treated subjects showed significantly greater deposition of collagen matrix at the pressure site at both the thirteenth (p = 0.007) and nineteenth days (p = 0.001). At the tension site, a significant increase in the amount of collagen matrix was observed in non-irradiated specimens (p = 0.048) between days 7 and 19.

CONCLUSIONS

LPT caused significant histological changes in the alveolar bone during induced tooth movement, including alterations in the number of both osteoclasts and osteoblasts and in collagen deposition in both pressure and tension areas.

Use of the CO(2) laser on orthodontic patients suffering from gingival hyperplasia

OBJECTIVE

The present study aimed to assess the effect of the use of the CO(2) laser on the treatment of gingival hyperplasia in orthodontic patients wearing fixed appliances.

BACKGROUND DATA

Gingival hyperplasia is a condition very frequent in patients undergoing fixed orthodontic treatment. Amongst the treatments available for this is the use of surgical lasers.

METHODS

Ten patients entered this study and signed an informed consent. Seventy-five anterior teeth with gingival hyperplasia were selected for laser surgery. Prior to surgery, the length of the crowns were measured using a digital caliper, and depth of the pocket was probed. The hyperplasic gingival was removed with a CO(2) laser under local anesthesia. Immediately after surgery, measurement of the length of the crowns and probing were carried out and were repeated.

RESULTS

The results were statistically analyzed and significant differences were detected regarding the length of the crown (p = 0.000) and depth of the gingival sulcus (p = 0.000).

CONCLUSION

It is concluded that the use of the CO(2) laser was effective in the treatment of gingival hyperplasia.