Page 48 - DP.qxd

IMPLANTOLOGY secTION

“ENHANCiNG PRECiSiON iN DENTAL

iMPLANT iMPRESSiONS: A novel

technique for deeply placed implant”

Gopal Goel

Ensuring a precise fit between dental implants and the
superstructure (prosthesis or supported framework) is vital
for the long term success of implants and implant-supported
prosthesis.
There are several factors which need to be taken care of, for
long term success of implants and implant supported prosthetic
complex. One factor which may influence the accuracy of the
definitive prosthesis is the stability and accurate pickup of the
impression coping in polymerised impression material.
In such cases, where implant lies well below the gingival
margin (deeply lying inside the bone), meaning that most of the
impression coping will also be situated subgingivally with no
contact (or not enough contact) with the impression material.
(Figure 1)
This can result in: Fig 1: Left side impression coping is placed deeper than right side
impression coping
a) Open tray Impression coping not getting picked-up inside
the impression
b) Reduced stability of the impression coping, allowing it to
rotate while fastening the implant analog.
This situation is more challenging when we record impressions
for single implant.
While longer impression copings have been suggested as a
solution, only a few implant systems offer this option. Moreover,
some companies provide locking space for rigid impression
material to flow over the head/body of open tray impression
copings.
There are 2 primary implant impression techniques:
a) Open tray impression technique
b) Closed tray impression technique
However, the most preferred technique used to record deeply Fig 2a: Pattern resin – roll and extension loop (front view)
placed implants is: Open tray impression technique.
This article presents a simple yet groundbreaking approach
using a roll/loop of pattern resin applied around the top of
transfer coping, along with tray adhesive on the impression tray
and impression coping during an open tray impression.
The hardness and retention loop of pattern resin materials
provide a secure grip for vinyl polysiloxane (VPS) impression
materials, enhancing stability and minimising the risk of
impression coping not being adequately captured. The roll/loop
of pattern resin increase the surface area and create undercuts.
The application of VPS adhesive bolstering the adhesion of
impression material to the coping and impression tray.
As a result, the impression coping remains resistant to Fig 2b: Pattern resin – roll and extension loop (occlusal view)

48 Dental Practice i July-August 2023 i Vol 19 No 4