Case Reports of Aesthetic Rehabilitation by Richmond Crown in Maxillary Anterior Teeth: A Forgotten State of Art

ABSTRACT

After endodontic therapy, restoring severely broken or damaged crown structure is a difficult task in conservative dentistry. Regular post and core followed by crown repair cannot restore a crown with steep incisal guidance, very little overjet, and highly damaged crown structure. Richmond crown is better recommended in these situations since Richmond crown is a crown having post. It is prepared as a single piece having a ceramic facing. We frequently encounter teeth having very less or no clinical crown portion that are structurally damaged. Support and retention of the restoration are challenging to achieve in such situations. The rehabilitation of anterior teeth that has been endodontically treated and structurally impaired is reviewed in two cases.

INTRODUCTION

It has always been difficult to combine post-endodontic restoration with aesthetic rehabilitation. To establish straight alignment for crown insertion after significant tooth structure loss from caries, fracture, or developmental problems is always a challenge in restorative procedures.

Richmond crown has successfully used post and core treatment for years when the tooth’s remaining structure is too weak to support a large prosthetic crown. The treatment of a tooth with structural weaknesses may be complicated by fracture, loss of the restorative seal, displacement of the crown, and periodontal injury to biological width invasion during marginal preparation.[1] To properly restore such a tooth, various procedures are available. The Richmond crown is one of the tried-and-true methods for handling such instances. Richmond crown is a single-piece, post-retained crown with a porcelain facing.[2] In this paper, the role of the Richmond crown in the management of anterior teeth with reduced structural integrity is covered with two case reports.

CASE REPORTS

Case 1

A male patient (35 years old) came to the department of conservative dentistry and endodontics for aesthetic restoration of his cervically fractured left central incisor with retained root piece. The patient had spacing between teeth, gingival tissue growing over the crown, and an Ellis Class IV fracture at the cervical edge [Figure 1.1]. For the cosmetic and functional rehabilitation, composite resin-based fiber post and core construction and Richmond-style post and core fabrication were the two potential treatments. Due to the Richmond crown’s superior strength over the fiber post, the second alternative was preferable. Diastema and a badly damaged crown structure made it unfavorable to build a crown over a fiber post and core using composite resin due to strength and aesthetic concerns.

Figure 1.

(1.1) Pre-operative picture, (1.2) Gingivectomy done crown lenghtening, (1.3) Healing after gingivectomy, (1.4) Recording post space impression, (1.5) Post space impression, (1.6) Impression recorded using alginate, (1.7) Metal try-in, (1.8) Radiograph after metal try-in, (1.9) Cementation of richmond crown

Treatment

Seven days after the left central incisor of the maxilla underwent successful root canal therapy and due to the gingival tissue’s overgrowth, the crown lengthening was done [Figure 1.2]. After 15 days, the patient was contacted, and there was successful healing [Figure 1.3]. To obtain the correct alignment for the placement of the Richmond crown, a significant amount of damaged tooth structure was removed from the labial surface of the tooth. The rest of the tooth structure of the crown was prepared circumferentially, and the post space was created using piezo reamers from Mani, INC. in Japan. The palatal surface had a chamfer, while the buccal surface had shoulder finish margin preparation. Green inlay wax (GC Japan) was used to create an impression of the post space [Figure 1.4]. In the post space area, a 21-gauge orthodontic wire (Pigeon Dental Stainless Steel, India) was adjusted, and its length was verified on a radiograph. Green inlay wax was used to make an impression of the post gap over a J-shaped wire [Figure 1.5]. After that, the alginate impressions were made for the preparation of the crown with the help of Zhermack Tropicalgin (Germany) [Figure 1.6]. Following the preparation of the cast post and core, a metal try-in was conducted [Figure 1.7]. To ensure the post fit, a radiograph was done [Figure 1.8]. The tooth was prepared using a custom-made cast post and porcelain-fused core (Richmond Crown). The final crown was positioned, and the occlusion was adjusted. The high points were noted and adjusted. Glass ionomer cement resin modified (GC Japan) was used for the final cementation [Figure 1.9].

Case 2

A 70-year-old male patient who had a broken upper right front tooth and needed an artificial tooth to replace it presented to the Department of Conservative Dentistry and Endodontics, in our college. After collecting a thorough medical history, it was discovered that the patient had previously undergone post and core treatment. His maxillary right central incisor crown, which was supported by the previously created post and core, became loose and fractured, along with the post in the root canal. Clinical evaluation revealed a prosthesis that had detached [Figure 2.1]. Richmond crown was also planned in this instance because of its favorable strength and aesthetic qualities.

Figure 2.

(2.1) Pre-operative picture, (2.2) Post retrieval, (2.3) Post space impression, (2.4) Radiograph after metal try-in, (2.5) Richmond crown, (2.6) Cementation of richmond crown, (2.7) Post-operative picture

Treatment

Root canal therapy was performed after a separated post retrieval using H-file (Mani, INC, Japan) [Figure 2.2]. Green inlay wax was used to imprint the post space. (GC Japan) [Figure 2.3]. Cast post and core preparation was followed by metal try-in. To ensure the post fit, a radiograph was done [Figure 2.4]. The tooth was prepared using a custom-cast porcelain core and post (Richmond crown) [Figure 2.5]. The final crown was positioned, and the occlusion was adjusted. The high points were noted and adjusted. Type I glass ionomer cement (GC Japan) was used for the final cementation [Figures 2.6 and 2.7].

DISCUSSION

Special procedures are needed for the rehabilitation of a tooth when a significant percentage of crown structure has been destroyed, as in the examples mentioned above, due to cavities, prior endodontic treatments, or fractured prosthetics. The Richmond crown was first offered in 1878.[3] Ferrule collar is used in addition to providing an anti-rotational effect[2] to boost mechanical resistance and retention. Grossly deteriorated or severely broken down single teeth with very little remaining crown height are a few indications that a Richmond crown is necessary.

Similar to the first case, there was not much tooth structure left, and the diastema made it the perfect case for a Richmond crown. Additionally, less cervical tooth structure is subjected to forces of flexion, and this design provides greater cervical strengthening than other post systems.[4,5] As a result, when all considerations are taken into account, the Richmond crown is highly recommended for restoration.

Failure of post- and core-treatment was present in the second case. A constraint in these situations is the necessary thickness of the tooth structure needed to cement the crown due to the severely damaged tooth structure. If the core is created extremely thin to make up for this insufficiency, it is weaker and also has sharp margins and edges that act as stress points for the crown above it. When less crown cutting is needed to achieve two axes parallel in a severely deteriorated tooth, Richmond crown is the best treatment option.

This design’s benefits are that it can be customized to the root configuration, it has low or no stress at the cervical margin, and excellent strength.[3] The operator should weigh the benefits and drawbacks of each type of post and core system, as well as the Richmond crown treatment modality, before deciding on a technique that will meet the case’s objectives while causing the least amount of stress and maximal retention. Richmond crown preparation needs a single path of insertion and withdrawal. However, Richmond crowns were strongly suggested in situations when the maximum amount of tooth structure had been lost and further tooth preparation was not necessary. Even though there are a variety of post designs that can be employed in a clinical setting, the success of the post depends on how much of the tooth’s natural structure is still present following endodontic therapy.

Always choose saving the tooth over extracting it and then getting treatment for a crown, bridge, or implant. Later treatment requires more time –consumtion and intrusive procedures. Even so, there are some conventional methods that are highly helpful in these situations depending on the circumstance.

CONCLUSION

The aesthetic rehabilitation of male patients with deficient maxillary central incisor crown structures is described in these clinical reports. An alternative to the current trends in implantology, which have undermined the conservative paradigm was to restore function and appearance using Richmond crowns. Therefore, it is the clinician’s primary duty to assess the clinical situation and choose the suitable operation that is most suited for the patient to enhance both appearance and functionality.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.