Supragingival Minimally Invasive Bonded Onlays: The Replacement for Full Crowns

Supragingival Minimally Invasive Bonded Onlays: The Replacement for Full Crowns

Photographs show teeth structure which is badly broken down and which is restored with help of supragingival bonded onlay and shows how healthy the teeth is after supragingival margin.

Badly broken down tooth restored with a supragingival bonded onlay.

Indications For Bonded Onlays

The indication for supragingival minimally invasive bonded onlays is simple: Any situation where the need for a full crown would have been identified and the tooth has not yet been cut for a crown. It is always preferable to make restorative dentistry healthier by retaining a supragingival margin and preserving tooth structure. Nevertheless, this is a departure from the popular view and traditional recommendations for bonded onlays. Bonded onlays have been indicated for simple cases that fulfill strict requirements, such as sufficient tooth structure available (Figure 5.1a–c), acceptable tooth color (Figure 5.2a–c), ideal location in the arch (Figure 5.3a–d), existing supragingival margin (Figure 5.4a–d), ideal occlusion (Figure 5.5a–g) [1,2,3,4,5]. When these requirements are not fulfilled, traditional full crowns have been indicated. With such strict recommendations, it is not surprising that well over 95% of teeth needing an indirect restoration end up being prepared for full crowns [6].

Image described by caption.

Figure 5.1 (a) Severe tooth structure loss, first and second molars. (b) Preparation for bonded onlay, no mechanical retention. (c) Postoperative view.

Image described by caption.

Figure 5.2 (a) Molar with internal discoloration. (b) After internal bleaching. (c) Finished onlay.

Image described by caption.

Figure 5.3 (a) Root-canal treated second molar in a bruxer, zero crown structure left. (b) Immediately following bonding with e-Max onlay. (c) Five years postoperatively. (d) X-ray of molar 5 years postoperatively.

Image described by caption.

Figure 5.4 (a) Tooth with deep subgingival caries treated with an onlay. (b) Finished margin elevation and enamel preservation. (c) X-ray taken immediate postoperatively. (d) Three years postoperatively.

Image described by caption.

Figure 5.5 (a) Severe bruxer. (b) After full upper arch with 2 mm vertical dimension of occlusion opening using VenusCeram™ Pressable. (c) Ten years postoperatively, all posterior onlays are functional. (d) A second severe bruxer. (e) Onlay preparations. (f) Cemented restorations. (g) Eight years postoperatively.

Indirect restoration should be reserved for badly damaged and weakened teeth. Less damaged teeth should be repaired with direct composite restorations. Direct composites can serve the patient very well. They allow for tooth structure preservation, are less costly for the patient and have excellent durability (Figure 5.6) [7]. Additionally, experience and clinical studies show that direct composites can perform as well as or may outperform indirect inlays [8]. For this reason, I do not recommend the use of indirect inlays. Only when the tooth is badly damaged, including badly weakened or missing cusp or cusps, or in the case of a fracture, is the option of an indirect onlay preferred to a direct composite. While it is possible to restore such teeth with a direct technique, it is more difficult and time consuming to perform a free-hand reconstruction of the morphology of a tooth’s occlusal surface, and the results are usually less than ideal. Additionally, some degree of fracture resistance is added by constructing the occlusal surface with a higher-modulus, strong, restorative material, such as porcelain. Very large composites, as in the case with very large amalgams, are less durable and predictable [9,10,11]. Endodontically treated posterior teeth should have full occlusal coverage [12] but are ideal for supragingival minimally invasive onlays, which preserve more of the already badly compromised tooth (Figure 5.7a,b) [13].

Image described by caption and surrounding text.

Figure 5.6 Direct composite restoration, indirect inlay not needed.

Image described by caption.

Figure 5.7 Weak tooth prone to fracture: (a) Only the periphery of the tooth is left. (b) After full-coverage onlay.

Clinical experience and the literature show that different outcomes can be expected from restoration, depending on the amount of remaining tooth, extension of the caries, old restorative material or fracture, as well as other circumstances. For these reasons, modifications and different types of preparation and restoration should be considered [14]. Posterior teeth requiring an indirect restoration can be divided into three major categories:

  • simple partial and full coverage on vital teeth;
  • complex partial and full occlusal coverage requiring buildups on vital teeth; and
  • complex full coverage on endodontically treated teeth or teeth with vertical fractures.

Simple Partial and Full Coverage on Vital Teeth

In cases where one or more of the cusps are undermined, fractured or missing, and must be onlayed (Figure 5.8a–d), a direct restoration would not be indicated. Simple cases have ideal, natural, tooth color, and the amount of remaining tooth structure, especially the periphery of the enamel, is sufficient, the final preparation is more than 2 mm from the pulp, and the existing margins are supragingival. Using a supragingival protocol would allow the margins to remain supragingival, without the need for dentin sealing or buildups. These are the cases that most experts recommend for bonded onlays. Currently, however, these cases are usually treated with full crowns (Figure 5.9a–e) [15]. Full-mouth rehabilitation is also well suited for simple onlay preparation. Many of these cases are in patients with severe occlusal wear, and, although some experts consider severe occlusal wear a contraindication to bonded onlays [2], condemning these patients to a mouth full of crowns, much experience shows that bonded onlays cases have excellent results in such patients (Figure 5.10a–e).

Image described by caption.

Figure 5.8 (a) Fractured distobuccal cusp. (b) Supragingival preparation. (c) The finished restoration.

Image described by caption and surrounding text.

Figure 5.9 (a) This is an ideal tooth to be considered for onlay. (b) After removal of amalgam. (c) Caries indicator. (d) Finished preparation. (e) Finished restoration.

Image described by caption.

Figure 5.10 (a) Full lower rehabilitation with onlays and veneers. (b) Onlay preparation. (c) The finished restoration. (d) The restoration 3 years postoperatively. (e) Eight-year postoperative x-ray.

Complex Partial and Full Occlusal Coverage Requiring Buildup on Vital Teeth

Badly damaged vital teeth require dentin sealing and some type of buildup, such as where the caries is very close to the pulp, where large undercuts and a weak cusp or cusps need to be reinforced, and cases where the caries is deep at the cervical margin area, and where enamel margin preservation techniques or margin elevation technique must be performed (Figures 5.11a–c, 5.12a–d). As these teeth are vital, color is usually not generally an issue. Traditionally, these cases have been recommended for crowns. Nevertheless, with the advances in adhesion, and materials, and by implementing a supragingival protocol, these cases can be very successful with partial coverage supragingival restorations.

Image described by caption.

Figure 5.11 (a) This badly damaged tooth needed onlay using caries detector to preserve as much tooth as possible and a supragingival margin. (b) After buildup and dentin sealing. (c) The finished onlay.

Image described by caption.

Figure 5.12 (a) A deep subgingival margin. (b) Elevation procedure. (c) After buildup. (d) The finished restoration.

Complex Full-Coverage Endodontically Treated Teeth or Teeth With Vertical Fractures

Only gold members can continue reading. Log In or Register to continue

Stay updated, free dental videos. Join our Telegram channel

Feb 19, 2019 | Posted by in Periodontics | Comments Off on Supragingival Minimally Invasive Bonded Onlays: The Replacement for Full Crowns

VIDEdental - Online dental courses

Get VIDEdental app for watching clinical videos