Effect of Hyperbaric Oxygen on Implants in Radiation-Treated Cancer Patients

Objectives: An outcome assessment of implants treated by hyperbaric oxygen (HBO) pre- and post-placement in patients with history of head and neck cancer treated with surgery and radiotherapy.
Methods: Study design consisted of a retrospective analysis using patients’ medical and dental records of treatment from 1988 to the present. Data included number of consecutively entered patients treated, treatment date, number of implants placed and their location, date and types of prosthesis provided, complications encountered regarding soft tissue, implants, prostheses and related components, dosage of radiation received to the primary site and units and courses of HBO therapy received. Time intervals between implant placement and uncovering, from implant placement to prosthesis completion, and time lapsed from start to finish of treatment were analyzed. Relative risk was used to test statistical difference.
Results: Of the patient cohort of 100 patients 74 patients (45 male, 29 female) with 412 implants (86 in maxilla, 309 in mandible and 17 at extra-oral sites were included for review/assessment. Prior radiation therapy ranged from 2700 – 7500 cGy (5500 cGy average). Patients underwent 20 dives HBO pre- implantation and 10 dives HBO post- implantation (range of 30 – 90). With a median follow-up of 6.1 years, 337 implants succeed, 44 implants failed (36 early failure and 8 late failure) and 31 implants remained uncovered (sleeper). Cumulative implant survival rate was 89.3% (67.4% for implants in maxilla and 95.8% in mandible, p <0.01). The survival rates of implants placed in native bone and in graft bone were 90.5% and 84.2% respectively (P =0.01). Definitive prostheses included 55 implant-supported fixed complete dentures, 10 implant-supported overdentures, 7 implant-supported FDPs and 8 maxillofacial prostheses. The mean service of the definitive prostheses was 37.5 months.
Conclusions: Implants in patients with history of cancer-related radiotherapy who underwent HBO:
1. Exhibited a promising implant survival rates with a median follow-up of 6.1 years for mandibular treatment.
2. Implants placed in mandible showed statistically significant higher cumulative survival rate than placed in maxilla.
3. Implants placed in native bone had higher survival rate than placed in grafted bone but no statistically significant difference.