Table 2.

Differences between periodontal diseases and peri-implant diseases.

		Natural Teeth	Implants
Inflammatory response	The degree of inflammatory response	Relatively weaker	More severe Nearly affects the marginal bone
	The proportions, numbers and densities of infiltrated inflammatory cells	Lower	Higher
	Infiltration of inflammatory cells	Restricted to the epithelium	Populated among connective tissue
Biofilm composition	Plaque structure	More complex	Simpler
	Beta lactam antibiotics resistance	Positive	Negative
	Red complex	Detectable in most periodontal diseases	Lower detection rate
Histological structure	Initial substrate for bacterial colonization	Mineralized organic dental tissue	Unmediated titanium base
	Participation of periodontal ligament or cementum	Yes	No
	Vascular supply of connective tissue	Supraperiosteal blood vessels Periodontal ligament vascular plexus	Supraperiosteal blood vessels
	Collagen fibers	Amount: less Direction: vertical	Amount: more Direction: parallel