*Review* **Etiology and Measurement of Peri-Implant Crestal Bone Loss (CBL)**

**Adrien Naveau 1,2, Kouhei Shinmyouzu 3,4, Colman Moore 5, Limor Avivi-Arber 6, Jesse Jokerst 5,7,8 and Sreenivas Koka 9,10,11,\***


Received: 31 December 2018; Accepted: 24 January 2019; Published: 1 February 2019

**Abstract:** The etiology of peri-implant crestal bone loss is today better understood and certain factors proposed in the past have turned out to not be of concern. Regardless, the incidence of crestal bone loss remains higher than necessary and this paper reviews current theory on the etiology with a special emphasis on traditional and innovative methods to assess the level of crestal bone around dental implants that will enable greater sensitivity and specificity and significantly reduce variability in bone loss measurement.

**Keywords:** Crestal bone loss; osseosufficiency; osseoseparation; peri-implantitis; photoacoustic ultrasound; brain–bone axis; foreign body reaction; overloading; radiography; CBCT (cone beam computerized tomography)
