Hyperbaric oxygen therapy use in patients receiving dental implants at risk for osteoradionecrosis

1. Hyperbaric oxygen therapy use in patients receiving dental implants at risk for osteoradionecrosis Tom Sarna 2/23/07 Chicago’s Midwinter Meeting

2. Implants Introduced by Branemark First titanium implant placed in a human volunteer in 1965. Commercially introduced in 1978. First intraoral application in 1979. Principle of osseointegration makes implants possible.

3. Osseointegration Def: Direct structural and functional connection between ordered and living bone and surface of load carrying implant. An additional clarification that there is direct connection between the bone and the titanium with no fibrous encapsulation. Fibrous encapsulated implants will be eventually lost.

4. 6 factors for osseointegration Material biocompatibility lmplant macrostructure Implant microstructure Surgical technique Status of the implant bed Loading conditions

5. Osteoradionecrosis (ORN) Most frequently occurs in the mandible A metabolic and tissue homeostatic deficiency due to radiation-induced cellular injury Ischemic necrosis of bone – Histopathology shows dominant factor is obliteration of inferior alveolar artery. Although microorganisms plays a role in contamination of ORN bone, osteomyelitis differs from ORN.

6. Histopathology of ORN 3 H’s - Hypocellular bone Hypovascular tissue Hypoxic tissue/bone Osteoclast activity reduced Osteoblast numbers reduced =collagen production decreased Bone marrow suffers vascular injury Arteritis of small caliber vessels Sclerosis of connective tissue Alteration of nutritional supply

7. Adjunctive Treatment for Irradiated Patients Antibiotics Penicillin pre/post surgery Tetracycline 100 mg daily prophylaxis Saline rinses Hyperbaric oxygen use

8. Hyperbaric oxygen therapy Does not affect necrotic bone Target is the viable bone and soft tissue Goal is to revascularize radiated tissues and to improve fibroblastic density Healing process requires oxygen for: Differentiation of fibroblasts Synthesis of collagen

9. Marx protocol 20 “dives” before treatment/10 “dives” after treatment “Dives” - The slang term for a cycle of pressurization inside the HBOT chamber regimen of oxygen at 2.5-2.8 absolute atmosphere pressure (ATA) for 90-120 minutes.

10. HBO2 Risks Mild problems : claustrophobia (in monoplace chambers), fatigue, and headache. More serious complications: myopia (short sightedness) that can last for weeks or months, sinus damage, ruptured middle ear, and lung damage. Major complication: oxygen toxicity can result in convulsions, fluid in the lungs, and even respiratory failure.

11. Hyperbaric oxygen therapy The only absolute contraindication to hyperbaric oxygen therapy is untreated pneumothorax. Relative complications include grand mal seizure, fever, the inability to clear the ears or sinuses. Promoting angiogenesis in tumor cells is also a risk factor in HBO therapy

12. HBO induced angiogenesis Marx demostrated a measurable change in angiogenesis after eight sessions Plateau at 80% to 85% of nonirradiated tissue level after twenty sessions After three years, tissue O2 levels were within 90% of original values suggesting that HBO induced angiogenesis does not regress with time significantly.

13. Study: Granstrom 1999, Osseointegrated implants in irradiated bone 4 groups A: irradiated: 32 patients/ 147 implants placed/79 lost (53% failure) B: nonirradiated: 26 patients/ 89 implants/12 lost (13.5% failure) C: irradiated + HBO use: 20 patients/99 implants/8 lost (8.1% failure) D: irradiated failed, retreated after HBO use:10 patients/43 implants/34 lost 1st (79% failure) / 5 lost 2nd (11.9% failure)

14. Study: Granstrom 1999, Osseointegrated implants in irradiated bone analysis No differentation between when implants are placed after irradiation – a good determinate of success rate Also, later placement helps explain the great improvement in success rate of Group D (79%/12%)

15. Merickse-Stern 1999

16. Merickse-Stern 1999 Shows a good success rate without hyperbaric oxygen in implant placement in irradiated bone

17. Weischer 1999 “Ten-Year Experience in Oral Implant Rehabilitation Irradiated patients vs. nonirradiated patients Small sample size irradiated patients (17 patients, 73 implants) No hyperbaric oxygen control group

18. Weischer 1999 “Ten-Year Experience in Oral Implant Rehabilitation Encouraging success rate of clinically osseointegrated implants in both irradiated and nonirradiated patients 75% success rate after 7 years in irradiated patients 86% success rate after 10 years in nonirradiated patients

19. Niimi 1998 Implants placed between 2-10 years are more successful Longer implants are more successful There were no failures of mandibular implants with or without adjunctive HBO therapy Higher doses of radiation lead to poorer success rates Very little data for maxillary implants

20. Wagner, 1998 “ Osseointegration of implants in irradiated patient” No hyperbaric oxygen use 275 implants in 63 irradiated patients Osteoradionecrosis: 1.6% 1 patient out of 62 Osseointegration: 97.9% 269 implants out of 275

21. Summary of implant studies in irradiated bone Attraumatic surgery is best determinate of healing without ORN Good success rate without hyperbaric oxygen Higher success rate when combined with hyperbaric oxygen Rarely is osteoradionecrosis caused by implant surgery, studies analyze success rate of osseointegration Should wait at least 1.5 years after irradiation to place implants

22. Hyperbaric oxygen centers in Chicago Arlington Heights Longevity Institute Arlington Heights, IL Lutheran General Hospital Park Ridge, IL Midwest Hyperbaric InstituteBolingbrook, IL Swedish Covenant Hospital – Wound Care Center 5145 N. CaliforniaChicago, IL