Treatment transitions with implants over an extended time period.

A sixty four year old female patient presented in 1991 with moderate to advance

periodontal disease and multiple missing teeth in both arches. (fig.1)The missing anterior

teeth had been replaced with removable partial dentures that were no longer retentive or

functional. Maxillary left quadrant teeth (12- 15) had a hopeless prognosis and these teeth

were slated for extracted. Comprehensive periodontal treatment was completed and

definitive treatment options were presented. Based on her experience with the removable

partial dentures, the patient wanted fixed prosthesis if possible.

The maxillary left sinus was grafted and six months later, five implants were placed and

subsequently restored with a fixed bridge segment. (fig.1a) The maxillary anterior segment

was restored with a 6 unit PFM bridge supported by natural teeth #’s 6,7 and 11.(fig.2,3,4)

Fig 1. Pre- treatment appearance without the removable partial dentures in place. Fig.

1a. Mandibular treatment completed with 5 implants and cantilever posterior extensions. Reverse dovetail attachments splinted the remaining molars to the implant segment.

Fig. 2, 3 and 4 Anterior smile with completed treatment. Occlusal view of the maxillary

arch restored with a ceramo- metal bridges. Below is a pan x-ray of the completed treatment that serviced the patient for 16 years.

Treatment was started in July of 1991 and

completed in mid 1992. Patient was

maintained on a regular recall basis for

many years. In 2008 she presented with a

toothache in the 6/7 area. The facial area

over both roots was red and swollen. That

segment of the bridge was mobile and a

radiograph indicated both bridge abutments

(6 & 7) had fractured near the gum line. The

existing right posterior bridge extending

from 2 to 5 would have had to be replaced

and extended to #11 if a FPD was considered.

That would be a significant span with multiple abutments on the right and only a single

abutment on the left. That option did not offer a very predictable long term prognosis.

Utilizing the implant supported bridge on the left, for additional support would have entailed

considerable additional treatment and expense.

The treatment plan selected allowed the right and left posterior bridge segments to remain

intact. It involved the following: # 6 crown elongation, endodontic treatment and a cast

post; extraction of #7 and the placement of two implants in sites 7 and 9; a four unit PFM

bridge supported by the two implants and single PFM units on #6 and 11. There was

insufficient bone in the anterior area and a block graft was necessary, in order to support

implants. (Fig 5)

Bone was harvested from the ascending ramus and secured with two mini screws. Two

implants were placed at the same time (#7 = 3.5 mm x 13 Nobel Groovy, and #9 = 4.3 x

13 Nobel Groovy). Implants were placed in March of ‘08 and restored in August. The

implants were placed at converging angles to dissipate loading. (Fig.7, 8, 9, 10)

Fig 5. X-ray with the two new implant in place. Small screws were used to secure the bone

graft. Endodontic treatment and crown lengthening was completed prior to second stage

Fig. 6 A laser was used to expose the implants and avoid laying a large flap.

Fig. 7 Impression posts in place. Note the angle diversion of the central axis of the implants.

The central Axis of the implants was spread to the distal as well as one implant to the facial and

one slightly to the lingual. Custom cast abutments were fabricated to correct the emergence angulation.

The abutments were seated and a cast verification jig was made to verify the location of the

implants. (Fig.11,12) Once the cast was determined to be accurate, the PFM frame was

waxed and cast. The copings for the single units (6 & 11) were also cast at that time. (Fig.

13,14,15)

Fig.11 & 12. Resin matrix constructed on the

abutments to verify cast accuracy. If the matrix did

not accurately and passively on the abutments, the

resin would be sectioned with a thin disc and then

picked up intra orally with a brush bead technique.

The cast would then be altered as well and the

casting made. The framework is then again tried in

the mouth and if necessary, picked up in a secondary

impression. That was not necessary in this case.

Fig.13,14 and 15 illustrate the completed frame

work just prior to clinically checking it in the mouth.

During the integration period, there was a temporary

fixed anterior resin bridge extending from 6 to 11. It

was therefore quite easy to gain access to the

treatment area and the patient was quite comfortable during this time as well.

Once the frame work fit was verified, the porcelain

was applied. A bisque bake try in appointment prior

to finishing the bridge, validate the patients esthetic

requirements. On insertion, the abutment screws

were torqued to the recommended value with a

Nobel Biocare electric torque driver. The screw

access holes were sealed with Teflon tape and Cavit

and the bridge was cemented with Temp Bond cement.

. … ….

If the abutments are very short and limited in parallelism so that it would compromise retention, IRM

can be used.

In seating an implant supported bridge, the occlusal contact is quite important. In this case, both the

cuspids and the first bi cuspids were used for anterior disclussion. Contact was checked with heavy

occlusal indicator paper and then with thin red or black until uniform shared contact is verified.

Occlusion is again checked a week or two after insertion. The restoration has been in function for two

years and three months. There has been no indication of bone loss and the bridge has been stable

since insertion.

The lower arch has been stable and without the need of any additional restoration or modification since

1992. The molars on the left have not lost any additional bone. The lone molar on the right has lost

additional bone over the past 16 years. Sometime in the future that may fail and an additional implant

in that site may be necessary. If that occurs, that segment can be attached to the anterior five implant

segment quite easily.

The final post op photos show a pleasing functional and esthetic result.

Post op pan

below

PAUL BINON DDS MSD