Patients with Thyroid Disorder, a Contraindication for Dental Implants? A Systematic Review

Abstract

The thyroid gland is composed of the thyroid follicles, considered to be the functional units of the thyroid gland. The synthesis of the thyroid hormones occurs in these follicles. Triiodothyronine (T3) and thyroxine (T4) are the thyroid hormones and affect metabolic processes all through the body. This systematic evaluation was performed to answer the following PICO question: “Can patients with thyroid disorders undergo dental implant rehabilitation with the same survival rate as patients without thyroid disorders?”. A systematic review of the literature was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statements to gather available and current evidence of thyroid disorders and its relationship with dental implants. The electronic search, in the PubMed and Cochrane databases, yielded 22 articles. Out of the 22 articles, only 11 fulfilled the inclusion criteria. Manual research of the reference list yielded no additional papers. According to the SORT criteria and answering our PICO question, level B can be established to conclude that patients with thyroid disorders can be rehabilitated with dental implants, with similar survival rates as patients without thyroid disorders. Papers with higher scientific evidence and bigger sample size should be carried out.

Medical considerations in the ageing implant patient

“…74 This condition is caused by the suppression of TSH and increase in T3 and T4, mainly caused by Graves' disease. 75 Over stimulation of osteoblasts and osteoclasts result in high bone turnover and a subsequent loss of bone mineral density. An additional consideration is that patients with hyperthyroidism can have atrial fibrillation and be on anticoagulant therapy which requires consideration during dental implant surgery.…”

“…Hypothyroidism results in reduced bone turnover by reducing both osteoblastic and osteoclastic activity. 75,77 Patients have been shown to have significantly lower peri-implant bone loss (compared with patients without hypothyroidism), hence are not at increased risk of dental implant failure. 78 One animal study showed significantly decreased area of new bone formation around the dental implant in rats with hypothyroidism which support the biological mechanism however its translation to human data is unclear.…”

“…One animal study showed significantly decreased area of new bone formation around the dental implant in rats with hypothyroidism which support the biological mechanism however its translation to human data is unclear 79 . A systematic review by Torrejon‐Moya, Izquierdo‐Gómez 75 evaluated implant success rates in patients with hyperthyroidism and hypothyroidism and reported a mean implant survival rate of 93.18% and 96.85% respectively. The authors concluded that patients with thyroid disorders can be rehabilitated with dental implants as they have similar implant survival rates (compared with patients without thyroid disorders).…”

“…), increased bone turnover and increased risk of osteoporosis and fractures 74 . This condition is caused by the suppression of TSH and increase in T3 and T4, mainly caused by Graves' disease 75 . Over stimulation of osteoblasts and osteoclasts result in high bone turnover and a subsequent loss of bone mineral density.…”

“…This tends to be caused by acquired hypothyroidism, Hashimoto's thyroiditis, drugs and irradiation. Hypothyroidism results in reduced bone turnover by reducing both osteoblastic and osteoclastic activity 75,77 . Patients have been shown to have significantly lower peri‐implant bone loss (compared with patients without hypothyroidism), hence are not at increased risk of dental implant failure 78 .…”