The use of barium sulfate for implant templates

Christoph H. J. Basten,a DMD, Dr Med Dent, MSD,= and John C. Kois, DMD, MSDh Diisseldorf, Germany, and Tacoma, Wash.

Fig. 1. Partially edentulous maxillae with ridge defect.

A controlled step-by-step approach for the use of templates for placement of dental implants is discussed. The provisional restoration, the blueprint for the final restoration, is duplicated in a radiopaque radiographic template. This illustrates the outline of the planned restoration in relation to the hard tissues. (J Prosthet Dent 1996;76:451-4.)

P lacement of dental implants requires meticu- lous planning and careful surgical procedures because the position of the implant cannot be easily changed af- ter implant osseointegration. Some templates use radiopaque markers to relate the planned implant posi- tion to the bone structures of the patient.Q Templates must be dimensionally accurate, rigid, and stable.3-5 Metal bearings are often used because they are not sen- sitive to distortion by the radiographic imaging proce- dure. However, they do not relate the contour of the fi- nal restoration to the patients hard tissue.

This article describes a procedure that uses radiopaque material, barium sulfate (Hypaque-sodium, Winthorp Pharmaceuticals, New York, N. Y.), for fabrication of a radiographic template during the diagnostic phase. The radiographic template, which is a copy of the provisional restoration, is used as a blueprint of the planned resto- ration. The full-contour radiopaque template enables the clinician to visualize the outline of the planned restora- tion in relation to the bone structures. Treatment plan- ning can be facilitated at this phase to allow any neces- sary procedures, such as ridge augmentation, to be com- pleted before implant placement. The procedure for making such a radiopaque template is described in this article.

Developing of a provisional restoration according to the functional and esthetic needs of the patient is illus- trated in Figure 1. The patient traumatically lost some maxillary teeth, and the trauma created a ridge defect. The interim removable partial denture (Fig. 2) serves as a provisional restoration, allowing the patient the op- portunity to evaluate the prosthesis esthetically and functionally.

PROCEDURE

Fig. 2. Interim partial denture (provisional restoration).

with (Fig. 4) the provisional restoration in place. (Casts may be poured in type III or type IV dental stone.)

1. Plan and adjust the outline of the prosthesis as needed.

2. When both patient and dentist are satisfied, make the impressions and casts both without (Fig. 3) and

Private practice, Diisseldorf, Germany. bPrivate practice, Tacoma, Wash.

3. Make an Omnivac shell (Buffalo Dental Mfg. Co., Syoset, N. Y.) over the cast with the provisional res- toration (made in step 2) in place.

4. Paint a suitable tinfoil substitute on the pretreat- ment cast, seal onto the pretreatment cast made in step 2, and use sticky wax to seal the Omnivac shell onto the pretreatment cast.

5. Make a mix of radiopaque resin by mixing one part barium sulfate with two parts acrylic resin powder

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Fig. 3. Cast of clinical situation without provisional res- Fig. 6. Boxing of cast with duplicated radiopaque teeth toration in place. in place ready for application of orthodontic resin.

Fig. 4. Cast of clinical situation with provisional resto- ration in place.

Fig. 7. Occlusal view of radiopaque template.

Fig. 5. Omnivac shell of provisional restoration on cast radiopaque.

(Jet Acrylic, Lang Dental Mfg. Co., Wheeling, 111.). Mix the powder thoroughly; then add the acrylic resin monomer to make the mixture fluid. (Barium sulfate is a nontoxic, white, tasteless, odorless pow- der used in intestinal radiography.)

6.

7.

8.

9.

10.

11.

Make a small opening in the shell and fill the shell with the mix of fluid radiopaqued resin. Inject the resin with a 12 cc Monoject disposable syringe (Monoject Division, Sherwood Medical, St. Louis, MO.) (Fig. 5). (When the resin polymerizes, it pro- vides a radiopaque duplicate of the provisional res- toration.) Separate the radiopaque provisional restoration from the shell and the cast. Cut and trim the opaqued provisional restoration to preserve only the block of teeth. Separate the resin teeth, trim them to open the gin- gival embrasures, and do whatever contouring is nec- essary to make them look like individual teeth. Position the teeth on the pretreatment cast (made in step 2), and use a small amount of sticky wax to hold them in place. (Because the ridge laps of the opaqued resin teeth were made in direct contact with the cast, except for a thin coating of separation me- dium, it is easy to replace them accurately on the cast [Figs. 6 through 81.) Box the opaqued resin teeth positioned on the cast with beading wax and include several of the stone teeth both anterior and posterior to the edentulous portion of the ridge (Fig. 6).

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Fig. 10. CT scan detail of panoramic overview. Fig. 8. Radiopaque template in place before CT scan (in- terim removable partial denture duplicated).

Fig. 9. CT scan of horizontal overview of maxilla.

12. Paint tinfoil substitute separating medium on the adjacent stone teeth and cast that will be contacted with the Orthodontic resin (Caulk-Dentsply, Milford, Del.), which will be applied next.

13. Apply Orthodontic resin by the salt and pepper method to create an acrylic resin overlay over the adjacent teeth and to hold the opaqued resin teeth in position (Fig. 7).

14. After the resin polymerizes, remove the assembly from the cast; then finish and polish it.

15. Fit the restoration to the patients mouth (Fig. 8) and have a computerized tomography (CT) scan (Syberview 1200 SX scanner, Picker Int., Cleveland Ohio) (DentalPlus software, Dimensional Medicine, Minnetonka, Minn.) made of the patients mouth witb the template and the radiopaqued teeth in place to show the relationship of the anatomic topogra- phy to the planned restoration (Figs. 9 through 11).

DISCUSSION

The number of the CT scan slices allows easy orienta- tion (Fig. 10) because the numbering is the same throngh- out the entire scan. Because the hard and soft tissue is shown in relation to the planned restoration, the need

Fig. 11. CT scan detail of vertical slice picture.

for augmentation can be clearly diagnosed before sur- gery. The CT scan is a useful guide for the surgeon, be- cause it provides a picture in a 1:l format. It helps plan- ning and performing augmentation and implantation procedures.

According to individual preferences, the radiographic template can be modified into any type of surgical tem- plate according to the individual preferences of the sur- geon.

CLINICAL SIGiNIFICANCE

Implant dentistry is a complex treatment modality and involves many specialists. Communication between spe- cialists and patients and careful treatment planning are imperative. The use of radiopaque radiographic tem- plates that demonstrate the outline of the planned res- toration in relation to the anatomic situation enables the clinician to plan and communicate the patients treat- ment needs to everyone involved in the process. Using

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THE JOURNAL OF PROSTHETIC DENTISTRY BASTEN AND KOIS

the same template, which is a duplicate of the provisional restoration, throughout the whole process of the diagno- sis reduces transfer errors during the augmentation and implant placement procedures to a minimum and allows a predictable step-by-step approach to implant dentistry.

REFERENCES

4. Modica F, Fava C, Benech A, Preti G. Radiologic-prosthetic planning of the surgical phase of treatment of edentulism by osseointegrated imulants: an in vitro study. J Prosthet Dent 1991:65:541-6.

5. Davarpanah M, Tecuianu JF, Ragot P, Jansen C, Moon J. An x-ray computed tomography study with radiographic splints in implant evaluation. Rev Stomatol Chir Maxillofac 1990;91(Suppl1):102-4.

Reprint requests to: DR. CHRISTOPH H. J. BASTEN LUEGPLATZ 3 D - 40545 D~JSSELDORF GERMANY 1. Burns DR, Crabtree DG, Bell DH. Template for positioning and

angulation of intraosseous implants. J Prosthet Dent 1988;60:479- 83.

2. Cranin AN. Fabrication of an implant stent for the edentulous man- dible. J Prosthet Dent 1993;69:352.

3. Engelman MJ, Sorensen JA, Moy P. Optimum placement of osseointegrated implants. J Prosthet Dent 1988;59:467-73.

Copyright 0 1996 by The Editorial Council of The Journal of Prosthetic Dentistry.

0022-3913/96/$5.00 + 0. 10/l/75580

Plaque-induced peri-implantitis i the presence or absence of keratinized mucosa: an experiment study in monkeys. Warrer K, Buser D, Lang P, Karring T. Clin Oral Imp1 Res 1995;6:131-8. Purpose. Controversy exists about the need for keratinized mucosa adjacent to teeth to maintain gingival health. Experimental studies have failed to demonstrate an association between the width of keratinized tissue and the progression of gingival lesions. Plaque control appears to be more critical to gingival stability. The importance of a band of dense connective tissue surrounding the soft tissue penetration of an endosseous implant has been described. This study examines the relationship of bacterial plaque accumulation and attachment loss in areas with and without keratinizing mucosa surrounding implants in a monkey model. Material and Methods. Five adult male monkeys were treated in this study by removal of the second premolar and the first and second molar teeth. All keratinized tissue was excised for one side of the jaw and retained for the contralateral side. A 3-month healing period preceded the placement of three IT1 implants in each edentulous space. Attempts were made to place half the implants in contact with retained root tips to allow periodontal ligament formation around the implants. All eight implants that were placed in contact with the roots were excluded from study analysis. Consequently, this study followed up 22 osseointegrated implants. Plaque control was eliminated for eight implants surrounded by keratinizing mucosa and eight implants surrounded by nonkeratinized mucosa. Wool ligatures were placed passively at the entrance of the periimplant sulcus and held in place by an oversized cover screw to induce plaque formation for implants in keratinized and nonkeratinized tissue. Results. Percent of bone to implant contact demonstrates no statistical correlation with induced plaque accumulation for either of the implant groups. Ligated implants without keratinizing mucosa demonstrated increased mucosal recession in comparison with nonligated implants with or without keratinzed mucosa or ligated implants with keratinized mueosa. Ligated sites with either mucosal characteristic demonstrated the largest loss of attachment. Conclusions. Because of the inductive capacity of the periodontal ligament, natural teeth universally possess a minimum width of keratinizing mucosa. This condition is in contrast to the situation where keratinizing tissue may be completely absent around dental implants. Without keratinized tissue, implants in this study demonstrated an increase susceptibility to bacterial plaque-induced tissue breakdown, loss of attachment, decrease in probing depth, and mucosal recession. It is hypothesized that the lack of keratinized mucosa leads to an increased susceptibility to plaque-induced tissue breakdown. 26 References-SE Eckert

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