Q. Explain What is Probing Depth?

This parameter is applicable to one stage implants when they are evaluated prior to prosthetic phase and used to evaluate the health of the implant after the prosthesis has been fabricated.

The periodontal depth indices are often used to evaluate the dental implants. The increase in sulcus depth around natural teeth is related to disease and bone loss. However, relating implant sulcus depth is controversial. Stable rigid fixated implants have been reported with pocket depths ranging from 2 to 6 mm. Partially edentulous patients consistently exhibit greater probing depths around implants than around teeth. Primary reason for increased probing depth around implants is that, the implant does not have a connective tissue attachment zone that extends approximately 1 mm above the bone as does a tooth. With an implant the probe goes beyond the sulcus through the type 3 collagen connective tissues and reaches closer to the bone. As a result, the probing depth next to an implant is greater than that of natural tooth.  The location of the probe tip sub-gingivally for a tooth depends on the pressure used, the presence of information and the angle at which the probe is introduced in the sulcus depth. The benefit of probing the implant
sulcus has been challenged in the literature. There is a potential damage to the fragile attachment or marring of the implant surface when the probing is performed.

The correct pressure recommended for probing is 20 grams, Yet conventional probing often exerts a force more than 5 times of this level  and is extremely variable. Pressure sensitive probes are now available to address these issues. Probing using fixed reference points on the abutment or crown margin allows the evaluation of the crestal bone loss versus tissue hypertrophy. As the sulcus depth increases, the oxygen tension reduces. Sulcus depth > 5 to 6 mm have greater incidence of anaerobic bacteria and require gingivectomy or revision surgery. Therefore to allow the patient to perform effective oral hygiene, the implant sulcus should be maintained at  less than 4 mm