References
Fisher FJ, Jones SA. Replacement of missing maxillary canines by resin bonded bridgework. Dent Update. 1990; 17:168-169
Kellet M. The etch retained metal restoration in clinical use. Br Dent J. 1987; 163:259-262
Two resin-bonded bridges – 30 years on
From Volume 44, Issue 8, September 2017 | Pages 793-794
Article
Restorative case studies with their associated therapies are commonly reported but publications of very long-term outcomes are rare.
Thirty years ago the replacement of lost upper canines was described in Dental Update1 in detail as to planning and clinical and technical execution. These restorations are still in place and, for clinicians, encouraging lessons can be learned.
The unusual feature of this case was that much less radical tooth preparation was employed rather than conventional methods which were prevalent at the time. Departure from convention intuitively creates reservations as to success and, at that time, etched bonded restorations had a variable reputation.2 It would seem likely that the latter reflected the level of clinical and technical care employed in a procedure demanding a meticulous approach in all respects.
The following text is an abridged version of the original article repeating detail which the author considers of importance. Figure 1 reproduces a figure from the 1990 publication. Figures 2 and 3 relate to a chance meeting with the patient, with the photographs taken opportunistically.
Occlusal relationships
Visual inspection of lateral jaw movement in tooth contact and repetition on a Whip-Mix semi-adjustable articulator showed guidance on the premolars (Figure 1a) and an aesthetically acceptable pontic could be provided which avoided damaging lateral contact. The minimal preparation is illustrated in Figure 1b. Suppression of over-eruption of lower canines was achieved by simple pontic tooth contact in the intercuspal jaw relationship.
Increase in tooth length
The upper first premolars had short clinical crowns so were lengthened palatally and interproximally by periodontal surgery, which included bone removal and placement of the gingiva at a lower level.
Tooth preparation and metalwork design
Sleeve fit is essential for retention, so the new longer palatal surface was ground to the vertical, extending well into the mesial but well short of the distal contact point of each upper first premolar. Tooth preparation was extended into the occlusal rest areas avoiding occlusal stops. Metalwork design followed the outline described above, with much emphasis on making margins easy to clean.
Technical procedures, materials, and fitting the bridges
In this case, a combination of techniques was used, their summation effect regarded as an advantage. Good union of metal to tooth was achieved by:
The resin-luting cement used was Panavia Ex, a low viscosity, low particle size filler with good surface bonding activity.
Cementation of the bridges was done with meticulous care following the manufacturer's precise instructions. The tooth surface, after acid etching, had to be completely clean and dry, with the metal receptive surface untouched as from the laboratory. Try-in, if needed, could be done prior to tin plating.
Figures 2 and 3 show the results after 30 years, the bridges still being in place and having required no further attention.