The use of flowable composite in recording the soft tissue profile of implant restorations

Accurate recording and transfer of the peri-implant gingival crest morphology to the working cast is fundamental in creating optimal contours and implant abutment finishing lines in the final restoration. This article describes a technique using flowable composite resin to record the morphology of the peri-implant gingival crest, following soft tissue conditioning through modification of the provisional restoration. The cured composite provides a clear three-dimensional representation of the peri-implant soft tissue profile, facilitating accurate transfer to the technical laboratory. The record can be disinfected and its removal from the provisional restoration is simple.

The achievement of optimal aesthetics in the anterior zone is paramount for implant success.¹ Although the peri-implant soft tissue profile is a signficant aspect for all implant supported restorations, it is particularly pertinent when managing patients with high smile lines or high aesthetic expectations.² Stock healing abutments and impression copings are commonly cylindrical in shape and consequently, do not mimic a natural tooth's soft tissue architecture.³ As such, techniques to gradually modify peri-implant tissue have been described to improve contour and emergence of the definitive restoration.^4,5 This modification generally takes the form of incremental additive and subtractive changes to an interim restoration.^2,4

Once optimal restoration contour and soft tissue form is achieved, accurate recording is required to transfer these dimensions to the master cast for the purpose of definitive restoration fabrication. A variety of techniques have been cited in the literature, with many involving construction of a customized impression coping to facilitate appropriate recording of the modified soft tissue profile.^{6,7,8,9,10,11} Using the interim restoration as a substitute for the impression coping has also been suggested.^12,13,14,15 However, these techniques require provision of a new master cast, involving further expense and an additional stage to the process. Other alternatives have included injecting impression material around the provisional restoration seated on the master cast, or recording the gingival level intra-orally using indelible pencil and transferring this to the working model.^2,16 Neither technique provides an accurate three-dimensional representation of the modified peri-implant margin.

The advent of digital dentistry has also seen various digital workflows being proposed to achieve the desired emergence profile.^{17,18,19,20,21} However, the suggested methods can be viewed as complicated, particularly if clinician and technician are not overly familiar with the process or system. These techniques are, of course, also inaccessible for those without digital facilities, and until these technologies are more widespread, viable conventional methods are still a necessity.

A relatively simple technique using flowable composite to record both the gingival marginal level and shape after modification of an interim restoration is described. This technique has advantages in that the composite can flow into the gingival crevice and onto the rolled border, accurately capturing shape and form. Once cured, the restoration and composite demarcation can be disinfected and located onto the working cast. Applying gingival substitute to this margin is more predictable and accurate in mimicking the clinical situation than previously mentioned techniques. The technique can be delivered chairside by the dentist without the need for technical colleagues, and is easy, efficient and cost effective.

Procedure

Once soft tissue manipulation of the peri-implant tissues is considered optimal, and the current implant level working model is verified as accurate, capturing the newly established profile can commence. The presenting patient underwent a delayed immediate implant placement to replace a traumatically involved UR1. A resinbonded bridge was provided as the initial interim restoration (Figure 1). A screw-retained provisional was subsequently made to enable appropriate conditioning of the gingivae, which did not exhibit an appropriate emergence profile (Figure 2). Over a period of 4 weeks, the emergence profile of the restoration was modified sequentially; Figure 3 illustrates initial blanching. Once optimal emergence profile and soft tissue contour (Figure 4) was achieved with the provisional restoration, a technique involving composite flowable resin was adopted to record this detail. The protocol is outlined as follows:

Place cotton rolls to isolate and maintain a dry field and sterilized poly-tetrafluoroethane tape (Domit AG, Oberhasli, Switzerland) on adjacent teeth (Figure 5).

Using a cotton pellet, remove moisture and saliva from the peri-implant margin (Figure 6).

Apply flowable composite to the peri-implant margin ensuring undercuts are not engaged on adjacent teeth (Tetric Evoflow, Ivoclar Vivadent, AG, Schaan, Leichtenstein) (Figure 7). Remove excess, and light polymerize with the tip at a distance of 1 mm, for 20 seconds (blue phase, 1500 mW/cm², Ivoclar Vivadent). A second increment of composite could be applied depending on the steepness of the emergence and the depth of the peri-implant sulcus.

Unscrew the restoration to the manufacturer's protocol and disinfect (Figure 8).

Locate onto the working model and apply soft tissue substitute to the captured margin (Gingifast, Zhermack, Romagna, Italy) (Figures 9–11).

Remove the crown from the model, remove the applied flowable composite and polish with discs and finishing burs as required prior to replacing in the patient's mouth (Figure 12).

Once the definitive restoration is constructed, this can be fitted to the manufacturer's instructions (Figures 13 and 14).