Experimental Peri‐Implant Tissue Breakdown Around Hydroxyapatite‐Coated Implants

Abstract

This study monitored experimental peri‐implant tissue breakdown around hydroxyapatite (HA)‐coated titanium dental implants. Thirty‐two HA‐coated cylindrical implants, in groups of two, were bilaterally inserted in the posterior maxilla and mandible in 4 Macaca mulatta monkeys. Two months after healing‐abutment connection, a 2‐month plaque control program was initiated. Clinical and radiographic recordings and peri‐implant submucosal microbial samples were then obtained (baseline). Cotton ligatures were next placed around the healing‐abutments and plaque control measures were abandoned. Clinical and radiographic recordings were repeated at 5 and 10 months post‐baseline. Microbial samples were repeated at 10 months post‐baseline, and ligatures were removed. Clinical, radiographic, and microbial examinations were again repeated at 11 months post‐baseline. Mean modified plaque index (mPI; P < 0.01), gingival index (Gl; P < 0.01), and bleeding on probing (BOP; P < 0.05) scores increased over the plaque accumulation period. The mPI, and GI scores decreased after ligature removal (P < 0.001). Mean probing depth (PD) and clinical attachment level (AL) increased between baseline and the 5‐ and 10‐month examinations (ΔPD 3.0 mm; Δ 2.7 mm; P < 0.05). PD values were reduced following ligature removal (P < 0.05). AL values and BP scores remained unchanged. A significant negative correlation was found between induced defect depth and width of keratinized mucosa at baseline (P = 0.03). At baseline, the submucosal microbiota was dominated by coccoid cells. Following ligature placement, the microbiota included a large proportion of Gram‐negative anaerobic rods, predominantly Porphyromonas gingivalis, Bacteroides forsythus, and Fusobacterium species as well as beta‐hemolytic streptococci. Ligature removal had a limited effect on the composition of the submucosal microbiota. This non‐human primate study indicates that ligature‐enhanced plaque accumulation is a precursor of progressive peri‐implant tissue breakdown around HA‐coated implants. The associated microbiota resembles that of peri‐implantitis and destructive periodontal disease in humans. This preclinical model may be useful to study modalities aimed at arresting peri‐implant tissue breakdown and at regeneration of bone in peri‐implantitis defects. J Periodontol 1997;68:59–66.

Healing of surgically created circumferential gap around Nano‐coating surface dental implants in dogs

“…[3] But the use of HA-coated dental implants remain still controversial, because some reports suggest that the HA coating may separate from the substructure, undergo dissolution in tissue fluids, and contribute to rapidly breakdown around the implants. [4] HA coating can be applied on metal implants by numerous methods and conditions. This study was to compare the healing response of various nano size coating [by ionbeam-assisted deposition (IBAD)] [5] HA-surface implants placed in surgically created circumferential gaps 12 weeks postplacement.…”

The effects of Hydroxyapatite nano-coating implants on healing of surgically created circumferential gap in dogs

“…HA is an osteoconductive and osteoinductive ceramic and it promotes strong biological bonding between implants and bone tissue. Although long-term clinical studies have presented highly successful results for HA-coated implants 6,7,15) , some researchers have expressed concerns about the potential for dissolution, resorption, and detachment of the coating, which may promote the loss of osseointegration [8][9][10] .…”

“…But controversy still persists over the long-term clinical effectiveness of HA-coated dental implants, because some reports suggest that the HA coating may separate from the substructure, undergo dissolution in tissue fluids, and contribute to rapid breakdown around the implants [8][9][10] . This failure may be due to the differences in chemical composition of .…”

Alveolar Augmentation: Focus on Growth Factors (BMPs)

“…Such studies have used alveolar saddle-type defects (Hunt et al 2001;Jovanovic et al 2003Jovanovic et al , 2007, chronic post-extraction defects (Barboza et al 2000(Barboza et al , 2004, dental implant dehiscence defects (Hanisch et al 2003), chronic peri-implantitis defects (Hanisch et al 1997a, b), and sinus augmentation for extended dental implant bone anchorage in the posterior maxilla (Hanisch et al 1997c;Lee et al 2013a). …”