Clinical Research
Late Effects of Head and Neck Radiotherapy on Pulp Vitality Assessed by Pulse Oximetry

https://doi.org/10.1016/j.joen.2016.02.016Get rights and content

Highlights

  • Long-term effects of RT on teeth in the path of ionizing radiation were investigated.

  • %SpO2 were measured 4-6 years after RT of intraoral and oropharyngeal tumors.

  • No significant difference found in %SpO2 between experimental and control groups.

Abstract

Introduction

Radiation therapy (RT) of malignant tumors in the head and neck area may have damaging effects on surrounding tissues. The aim of this investigation was to evaluate the long-term effects of ionizing radiation on pulp vitality by measuring pulp oxygenation levels (%SpO2) in patients with history of RT of intraoral and oropharyngeal tumors 4–6 years after treatment.

Methods

In an experimental group RT (n = 90, history of RT) and a control group CON (n = 90, no history of RT), pulp vitality was assessed by measuring %SpO2 by using pulse oximetry and pulp sensitivity by cold thermal testing. All anterior teeth without history of endodontic therapy of the participants in group RT were measured (n = 693), regardless of the quadrant and the irradiated area. An equal number of anterior teeth were tested in group CON.

Results

There was no significant difference between the %SpO2 levels in group RT (92.7%; standard deviation, ± 1.83) and group CON (92.6%; standard deviation, ± 1.80). All teeth in RT and CON groups showed a positive response to the thermal test. All tested teeth were considered vital.

Conclusions

Pulp %SpO2 was found to be within normal limits 4–6 years after RT. This suggests that RT may not have a long-term influence on pulp vitality, and reported short-term changes in pulpal microcirculation because of RT may be temporary.

Section snippets

Materials and Methods

This investigation was approved by the Ethics Committee of the Sírio-Libanês Hospital (São Paulo, Brazil; protocol #130). An informed consent was obtained from all human subjects who participated in this study. In total, 180 patients who agreed to participate in this investigation were selected for this study. Group RT had 90 participants who had received RT for malignant head and neck tumors at the Hospital Sírio-Libanês 4–6 years ago, including male and female patients between the ages of 35

Results

The mean age of the participants in group RT was 49.4 years (male, 50.3 years; female, 48.5 years), and it was 49.6 years in group CON (male, 51.1 years; female, 49.1 years). All patients in group RT had a history of intensity modulated radiation therapy (IMRT), and the mean amount of total radiation delivered to the tumor sites was 61.8 Gy. The most prevalent site of head and neck cancer was the oropharynx (66%), followed by the oral cavity (20%), the nasopharynx (8%), and the hypopharynx (6%).

Discussion

The use of pulse oximetry as an objective tool to determine pulp vitality has been demonstrated for teeth with a history of dental trauma 16, 20. However, there is still little knowledge about the use of pulse oximetry for the evaluation of teeth in situations other than trauma (13). There are few reports on the use of pulse oximetry for teeth in the pathways of ionizing radiation and, in particular, on the long-term fate of pulp tissue in irradiated areas.

There are conflicting reports on the

Conclusion

The findings of this study suggest that the dental pulp in the pathway of ionizing radiation during RT of the head and neck region may not undergo either a complete loss or a decrease in vasculature and blood flow 4–6 years after RT. The clinical changes commonly observed in the pulpal microcirculation, which were demonstrated to occur in the short-term, may only be of a temporary nature. This may suggest that often recommended preventive endodontic treatments or tooth extractions in patients

Acknowledgments

The authors deny any conflicts of interest related to this study.

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