Our study is a prospective study looking at the failure rates in root-formed implants in AIDS patients at 5 years post-surgical placement of the implant fixtures. Patients recruited for the study had to meet inclusion criteria which included diagnosis of AIDS measured by a pre-operative cluster of differentiation 4 (CD4) <200 cells/μL, age 18 years or older, and a minimum of one edentulous space requiring an implant as a viable restorative option. Exclusion criteria included current smokers, active periodontal disease, and non-restored remaining dentition. The study was conducted at a North Carolina community health center which serves a large group of patients infected with HIV, of which a substantial number met the CDC criteria for AIDS, CD4 <200 cells/μL. All participants recruited for the study were patients of the health center under the care of the center’s HIV specialist and were patients of record of the center’s dental clinic. Patients did not receive any financial compensation for participating in the study. Internal review board approval was granted for this study.

Bicon® root-formed implants were placed in all patients. These implants were chosen because of availability and previous experience with this brand. All patients that met the inclusion criteria gave consent and had a pre-operative discussion on the risks associated with implant surgery. All cases were presented at implant rounds, and a comprehensive restorative work-up including panoramic and periapical radiographs, study models, and treatment plan was completed prior to surgical placement of any implants. Pre-operative medical work-up included medical clearance by the patients’ physician, CD4 counts, and viral loads. No perioperative antibiotics were given.

Post-operatively, all patients were placed on chlorhexidine gluconate 0.12 % rinse. No post-operative antibiotics were prescribed. All patients in the study were undergoing highly active antiretroviral therapy (HAART). HAART includes nucleoside reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs), protease inhibitors (PIs), and integrase strand transfer inhibitors (INSTIs). Typical treatment includes two different NTRIs, along with a third drug, either an INSTI, a PI, or an NNRTI. Patients on HAART and Pneumocystis pneumonia (PCP) prophylactic medications were told to continue their current regimen. All implants were placed by the same two dental surgeons, and all patients were followed by the center’s HIV/AIDS specialist. Patients were followed up at 1 week, 4 weeks, at uncovering (4–7 months), and then yearly till 5 years. The bone quality and consistency of this cohort did not differ from the same age and gender non-AIDS population. Infection, mobility, need for implant removal, non-bony union, and clinical mobility were considered to be implant failures. Implants with exposed threads were considered failures. Implant success criteria constituted implants that had no clinical mobility at uncovering, no radiographic radiolucency, and allowed for loading and abutment placement.

Standard descriptive statistics were used to examine the distribution of key variables (age, gender, CD4 count at baseline and follow-up, and failure rate) in the sample. Due to the small sample size in this study (n = 16), the relationship of CD4 count and failure will be examined graphically and cases which failed are discussed individually in the "Results" section. A bar chart is presented to examine the relationship between implant survival and CD4 count at baseline. A non-parametric survival curve (using the Kaplan-Meier method) is estimated for individual implants (n = 33), which depicts the relationship between implant survivorship and time since procedure.