title: Clinical implications of calcifying nanoparticles in dental diseases: a critical review.
abstract: BACKGROUND
  Unknown cell-culture contaminants were described by Kajander and Ciftçioğlu in 1998. These contaminants were called nanobacteria initially and later calcifying nanoparticles (CNPs). Their exact nature is unclear and controversial. CNPs have unique and unusual characteristics, which preclude placing them into any established evolutionary branch of life.
  
  
  OBJECTIVE
  The aim of this systematic review was to assess published data concerning CNPs since 1998 in general and in relation to dental diseases in particular.
  
  
  METHODS
  The National Library of Medicine (PubMed) and Society of Photographic Instrumentation Engineers (SPIE) electronic and manual searches were conducted. Nanobacteria and calcifying nanoparticles were used as keywords. The search yielded 135 full-length papers. Further screening of the titles and abstracts that followed the review criteria resulted in 43 papers that met the study aim.
  
  
  CONCLUSIONS
  The review showed that the existence of nanobacteria is still controversial. Some investigators have described a possible involvement of CNPs in pulpal and salivary gland calcifications, as well as the possible therapeutic use of CNPs in the treatment of cracked and/or eroded teeth.
authors.affiliation: Restorative Dentistry Department, Riyadh, Saudi Arabia.
authors.forename: Mohammed S
authors.initials: MS
authors.lastname: Alenazy
authors.affiliation: Oral and Maxillofacial Pathology Department, Riyadh, Saudi Arabia ; Research Center, Riyadh Colleges of Dentistry and Pharmacy, Riyadh, Saudi Arabia.
authors.forename: Hezekiah A
authors.initials: HA
authors.lastname: Mosadomi
mesh_terms: D000818:Animals; D059587:Calcifying Nanoparticles / Q000737:chemistry / Q000378:metabolism* / Q000627:therapeutic use*; D002114:Calcinosis / Q000188:drug therapy* / Q000378:metabolism*; D006801:Humans; D008954:Models, Biological; D009057:Stomatognathic Diseases / Q000188:drug therapy* / Q000378:metabolism*; D014070:Tooth / Q000378:metabolism*
chemical_list: D059587:Calcifying Nanoparticles
keywords: calcifying nanoparticles; enamel repair; nanobacteria; pulp stone; sialolith