CHE COSA SAREBBE LA PAURA SENZA I MOSTRI FEMMINILI?

Fig 11.1

Successful apexification procedure, patient age 8.

STRATEGIES IN DENTAL DIAGNOSIS AND TREATMENT PLANNING 182

Fig 11.1 continued

(b) A year later, at age 9, traumatic horizontal fracture, (c) Electrosurgery was employed to access subgingival fracture margins, and to obtain hemostasis. (d) Brass dowel pin (Pindex) was loosely fitted to the crown on the bench, (e) Once fitted passively in the mouth, light-cured composite resin was used to fill the crown portion, and initial curing was done in the mouth. The post crown was removed to complete the light cure, and then cemented with a temporary cement, (f) Six years later, at age 14, a custom-cast post and core was fabricated and cemented permanently.

HOPELESS TEETH 183

was cemented into and onto the root with a tem-porary cement (Fig 11.1e).

EPILOGUE CASE HISTORY 11.1

Six years later (1995) the temporary post and crown came loose, and a custom cast gold post and core was fabricated and cemented perma-nently (Fig 11.1f). A temporary was made over this post and served until a porce-lain-fused-to-gold crown could be placed.

HOPELESS CASE 11.2

This patient, referred from another office in 1986, had a severe vertical fracture of tooth no.

8 (Fig 11.2a).

This 16-year-old girl had no dental restora-tions of any kind. After exposing pulp the frac-ture exited the root 5 mm below the alveolar crest, and easily made this tooth a candidate for extraction. She and her parents were des-perate to save the tooth.

Electrosurgical debridement and hemostasis were employed to clear the field for a one-sitting

Fig 11.2

(a) Both clinical and radiographic appearance suggest a ‘hopeless’ situation, (b) After controlling the field with electro-surgery, a one-sitting endodontic treatment was carried out. (c) The apical seal is just barely adequate, as maximum post length was needed in view of the anticipated orthodontic extrusion.

STRATEGIES IN DENTAL DIAGNOSIS AND TREATMENT PLANNING 184

root canal (Fig 11.2b). After sealing the apex with gutta percha, as much post space as pos-sible was created, and a direct pattern for cast gold post was made (Fig 11.2c). The post was inserted the following day, and a light cured composite resin provisional crown was ‘perma-nently’ cemented to the post (Fig 11.2d).

The tooth was then extruded orthodonti-cally, using a Hawley retainer with a coiled fin-ger spring off the anterior bow (Fig 11.2e). The finger spring engaged a facial ‘notch^’ created in the provisional. The extrusion was moni-tored weekly, and the provisional was reduced incisally and lingually as necessary. A bonded

Fig 11.2 continued

(d) Having a tooth in place within a day of the trauma was much appreciated by patient and parents, who understood that we were not yet ‘out of the woods.’ (e) Orthodontic extrusion was used to clear the fracture margin above the alveolar bone, (f) With an acceptable physiologic width for attachment established, definitive restoration could pro-ceed, (g) Eight-year follow-up, demonstrating successful retention of this ‘hopeless’ tooth.

HOPELESS TEETH 185

wire retainer stabilized the tooth after 6 weeks, with the fracture margin ending about 2 mm clear of the alveolar crest (Fig 11.2f).

EPILOGUE CASE HISTORY 11.2

Eight years later (1994), the patient was kind enough to return for follow-up and photo-graph (Fig 11.2g). As might be expected follow-ing orthodontic extrusion, the gfollow-ingiva had crept down somewhat, and minor electrosurgical gingivoplasty was performed to ‘even up’ the

crown length of nos 8 and 9. The tooth remains comfortable and functional.

HOPELESS CASE 11.3

Another variation on the theme, this 11-year-old boy was a sports enthusiast, and a series of sports-related traumas made him a regular in the office for several years. In early 1992 he presented with a full horizontal fracture of tooth no. 8 (Fig 11.3a). One-sitting root canal therapy was indicated, but electrosurgery was

Fig 11.3

(a) Full horizontal fracture, subgingival no. 8, of an 11-year-old patient, (b) Endodontics done in one sitting, post crown made using patient’s own clinical crown and brass dowel pin, 3 weeks after initial trauma.

STRATEGIES IN DENTAL DIAGNOSIS AND TREATMENT PLANNING 186

Fig 11.3 continued

(c) 6 weeks later another traumatic blow dis-lodged the temporary post crown, (d) Custom cast post coping was cemented permanently, with the crown fragment still serving as temporary, (e) Orthodontic treatment added to the normal daily stresses on this hybrid restoration, (f) 8 years af-ter the initial trauma, a definitive crown was placed over the post coping, and the crown frag-ment was finally retired.

HOPELESS TEETH 187

ruled out as a result of the severe contu-sion to the gingival tissues. Instead, a flap was care-fully reflected to clear the root for a rubber dam clamp. Endodontic and temporary post-crown procedures were performed, and the flap su-tured back to place. The tissue was healing well, and the tooth was comfortable, although still slightly mobile, just 3 weeks after the initial trauma (Fig 11.3b).

Less than 6 weeks later, another sports-re-lated injury caused the temporary post and crown to be knocked loose (Fig 11.3c). Fortu-nately the root was not fractured, and it was decided to fabricate a post-coping for better retention and to ‘bind^’ the root, creating a fer-rule effect. This was done, and the patient’s own clinical crown, relieved and filled in with light cured composite, was cemented ‘perma-nently’ to the post-coping (Fig 11.3d).

This arrangement held up through 2 years of orthodontic treatment (1993–94) (Fig 11.3e) and continued to serve until late in 1997 when, at age 17, a porcelain fused to gold crown was placed in its stead. The original post-coping remains as the foundation (Fig 11.3f).

HOPELESS CASE 11.4

To illustrate the fabrication of a custom-cast post-coping, we may consider this fragile but critical distal bridge abutment, the hemisected distal root of lower right second molar number 31 (Fig 11.4a). Given all it has gone through, such a tooth (or root) could well be consid-ered ‘hopeless.’ Nevertheless, the desire to maintain an intact dentition drives us to seek

Fig 11.4

(a) Hemi-section of lower molars can often preserve a sound root for many additional years of service. (b) Formed in the mouth, using a plastic core or dowel pin with addi-tional self-curing acrylic resin (Duralay), the intracoronal post pattern should draw easily, and seat positively on the prepared tooth.

STRATEGIES IN DENTAL DIAGNOSIS AND TREATMENT PLANNING 188

Fig 11.4 continued

(c) Demonstrating the steps in the fabrication of direct/

indirect post coping. The intraoral pattern must sit cleanly on the indirect die. (d) The coping is waxed di-rectly to and over the post pattern, creating a finished margin and collar of gold, and permitting directional changes for proper parallelism, (e) Bridge preparations, with double premolar abutments in the anterior, hemisected molar root at posterior. As a subgingival gold margin and collar have been established, it is easy to impress the distal abutment.

HOPELESS TEETH 189

strategies to preserve and utilize this delicate little ‘hemi-tooth.’ A cast post and core would generally be the next step, but we must take great care with such teeth, because intracoronal stresses can easily fracture the root longitudinally. A post-coping is indicated to provide intracoronal retention while at the same time ‘binding^’ the root circumferen-tially, creating a ferrule effect.

In fabrication of the post-coping, fit is criti-cal. Intracoronal cast posts must fit passively, because ‘tight’ fits can introduce stresses result-ing in subsequent root fractures. Care must be taken in fabrication to limit expansion of the pattern, to keep the casting ‘small.’

Extracoronal crowns and copings must also fit passively, to allow complete seating, with room for cement. In order to accomplish this, we try to maximize expansion of pattern and casting, keeping the casting ‘large.’ How do we make a combination casting of post and coping that meets both needs?

One approach is to use a direct/indirect technique. After post space and extracoronal preparation is complete, an acrylic pattern is made directly in the mouth. This one is using a plastic sprue pattern with Duralay resin, making an accurate pattern that seats cleanly onto the top of the prepared tooth (Fig 11.4b).

As resin tends to shrink in setting, and as the sprue pattern core has somewhat less capac-ity for thermal expansion than wax does, the resulting intracoronal casting should fit pas-sively.

An impression is made of the prepared tooth subgingivally, and as far into the post space as practical. The end of the post im-pression is augmented with wax, which, when the stone model is set, can be located and removed from below, allowing the direct post pattern to be seated accurately on the die (Fig 11.4c).

The extracoronal coping is then waxed over the direct pattern, which will allow the nor-mal expansion of lost wax for a ‘generous’ fit when cast in gold. The coping also allows a directional change, so that proper parallelism with anterior abutments can be achieved (Fig 11.4d).

Given the multiple procedures (root canal, hemisection, post-coping) performed on the distal root of no. 31, the fixed bridge is

dou-ble abutted in the anterior, and designed to be converted to a cantilever arrangement should the ‘hopeless^’ distal anchor root give out in the future (Fig 11.4e). This approach is discussed at length in Chapter 13. The

sche-Fig 11.5

Schematic diagrams review the steps in creating the di-rect/indirect post coping, (a) Post space and chamfer mar-gins prepared, (b) Intracoronal direct post pattern, (c) Im-pression of tooth and prepared margin, and post space (not necessarily complete). Wax ball added at end of post im-pression before pouring stone model, (d) Stone die, hol-low-ground from below to locate and remove wax ball, (e) Post pattern fitted cleanly onto die, with coping waxed over it. Gold finish margin and collar create finish margin for later overcasting.