A COMPREHENSIVE REVIEW OF SYSTEMIC FACTORS ASSOCIATED WITH PERI-IMPLANT DISEASES
Review Article
52 , 54 , 55
mediators . Underlying causes of osteoporosis include pre- and postmenopausal estrogen deficiency , excessive glucocorticoid intake , eating disorders such as anorexia nervosa and celiac disease . 56 , 57 Although the bone quality and strength are compromised in osteoporotic patients ; osteoporosis is not considered a contraindication for implant therapy . 58 , 59 In a recent systematic review , Javed et al . 60 assessed the effect of osteogenic coatings on the osseointegration of implants under induced osteoporotic conditions . Nearly 80 % studies reported that osteogenic coatings around implant surfaces enhance bone formation , bone-toimplant contact ( BIC ) and bone volume ( BV ) under osteoporosis-like conditions . This could possibly be accredited to the increase in surface roughness of the implant caused by osteogenic coatings , which facilitate the attachment of osteoprogenitor cells to the implant surface . Holahan et al . 59 conducted a retrospective study to evaluate whether a diagnosis of osteoporosis affected the survival rate of osseointegrated dental implants . In this study 59 , a total of 3,224 implants placed in 746 female patients aged at least 50 years old at the time of implant placement were assessed . The results showed that patients with a diagnosis of osteoporosis or osteopenia were not significantly more likely to develop implant failure compared to those without such a diagnosis . 59 Krennmair et al . 61 evaluated the implant treatment outcomes for patients suffering from autoimmune rheumatoid arthritis ( RA ) with or without concomitant connective tissue diseases ( CTD ). In this study , 61 34 female patients ( 25 isolated RA ; nine RA + CTD ) were included . At the mean duration of follow-up of nearly 46 month , all implants presented a survival rate of 100 %. In isolated RA patients , acceptable marginal bone loss ( MBL ) ( mean : 2.1 mm ; SD : 0.5 mm ), pocket depth ( mean : 2.8 mm ; SD : 3.2 mm ) and healthy soft-tissue conditions ( plaque / bleeding / gingiva index Grade 0 in 80 %) were observed . 61 Results from a case-series report , 62 showed a high implant survival rate during follow-up with a cumulative 3-year implant success rate of 96.1 %. In this study , RA patients demonstrated acceptable MBL ( mean : 2.1 +/ - 0.5 mm ) and satisfactory soft tissue conditions ; whereas CTD patients showed increased MBL ( mean : 3.1 +/ - 0.7 mm ). The study 62 concluded that a high implant and prosthodontic success rate can be anticipated in patients suffering from RA ; however , the authors emphasized that optimal oral hygiene assists in ensuring stable long-term survival of dental implants in patients with RA . 62 3.4 . Irradiation Osteoradionecrosis is usually observed several years following radiotherapy and is associated with local trauma within the hypovascular – hypocellular hypoxic tissues ( that occurs as a result of radiationinduced endarteritris ). 63 In this regard , the interval between the end of cancer therapy and placement of dental implants may contribute to the success or failure of osseointegration . Studies 64-66 have investigated the required time interval between radiotherapy and implant installation that may influence osseointegration ; however the results remain debatable . In a systematic review , Zen Filho et al . 67 assessed the safety of dental implants placed in irradiated bone and to discuss their viability when placed post-radiotherapy . Eight publications were assessed in this systematic review 67 and the results showed a total of 331 patients received 1237 implants . The time interval between irradiation and dental implantation ranged from 6 to 15 months . The overall implant failure rate of 9.53 % and osseointegration success rates ranged between 62.5 % and 100 %. 67 In another review , Javed et al . 20 assessed the implant survival rate after oral cancer therapy . In total , 21 studies were included in this review out of which , 16 studies reported that dental implants can osseointegrate and remain functionally stable in patients having undergone radiotherapy following oral cancer surgery . 20 The authors concluded that dental implants can osseointegrate and remain functionally stable in patients having undergone oral cancer treatment . 20 3.5 . Human immunodeficiency virus infection Human immunodeficiency virus ( HIV ) infection is characterized by progressive immune system failure that gives rise to the development of opportunistic infections and neoplasms . The virus invades CD4 + T lymphocytes , macrophages and dendritic cells , and the CD4 + T cell counts gradually decrease as a result of direct cytopathic action or cytotoxic CD8 + T lymphocyte-mediated attack . In a recent systematic review , Ata-Ali et al . 68 attempted to answer the following focused question “ does HIV infection have an impact upon dental implant osseointegration ?” The combinations of search terms resulted in a list of 132 titles . Consequently , 101 studies were excluded on the basis of the evaluation of the title and abstract , thereby leaving 9 articles for eligibility assessment . Amongst the studies included in this systematic review , a total of 173 dental implants were placed in 80 patients ( 135 implants in 56 HIV-positive individuals and 38 implants in 24 HIV-negative patients -control groups ). A single loss of dental implant osseointegration was recorded in an HIV-positive patient . 68 In the study by Stevenson et al . 69 , 40 dental implants were placed in 20 HIV-infected patients . No implant osseointegration failures were recorded after 6 months of follow-up . Similarly , in another study of 39 dental implants placed in 24 HIV-infected patients , no implant osseointegration failures were recorded after 12 months of followup . 70 Should dental implants placed in HIV positive patients sustain bone levels in the long-term ( 5 years or longer ) requires further investigations . 3.6 . Genetic factors Jacobi-Gresser et al . 71 assessed diagnostic markers to predict titanium implant failure . The study reported that tumor necrosis factor-
42 Stoma Edu J . 2017 ; 4 ( 1 ): 39-45 . http :// www . stomaeduj . com