The 'New' ceramic veneers

Written on 04/04/2018
Masoud Abu Zant

Q

I quit placing ceramic veneers during the great recession because patients either could not afford them or did not want to spend their discretionary money. I'm seeing ads and courses on ceramic veneers again. Has there been much change in this concept over the last few years? If so, what changes have occurred, and are these restorations still considered state-of-the-art?

 

A

To briefly answer your two questions, yes, a significant amount of change has happened in the area of ceramic veneers, and yes, they are an important and major procedure for all dentists involved in esthetic dentistry. Almost all people want to look their best, look younger, have high self-esteem, and feel that their appearance is within the normal realm.

The indications for veneers are clear. There are numerous clinical situations in which the lingual surfaces of the anterior teeth are not carious or worn excessively, but one or more of the following challenges indicate veneers instead of crowns:

• Teeth that are discolored more than typical bleaching can overcome

• Malpositioned teeth that need to be changed to provide a homogeneous smile appearance, but patient does not want to undergo orthodontics

• Pitted teeth

• Mottled teeth

• Patients with unsightly gingival recession

• Teeth needing lengthening

• Multiple diastemas

• Chipped or broken teeth

Properly placed ceramic veneers have a history and reputation for serving longer, and for being more adequate esthetically than PFM crowns. Whether or not those clinical observations will remain true with the current generation of lithium disilicate or esthetic zirconia crowns is yet to be determined.

How Have ceramic veneers changed in recent years?

To discuss this topic I will list the steps in the conventional technique for placing veneers, and I will indicate those steps in which there has been significant change.

1. Diagnosis and treatment planning-Patients need to be educated to know that ceramic veneers are available, conservative, well proven, and long lasting. They should be informed about other alternatives such as tooth bleaching or crowns. In my opinion, too many veneers are accomplished when more conservative procedures should have been done (figures 1 and 2).



Figure 1: This 28-year-old patient had malpositioned teeth that could have been corrected by orthodontic treatment. However, there were three colors represented in the four maxillary anterior teeth that would have required veneers after the orthodontics. He decided not to have the orthodontic treatment.



Figure 1: This 28-year-old patient had malpositioned teeth that could have been corrected by orthodontic treatment. However, there were three colors represented in the four maxillary anterior teeth that would have required veneers after the orthodontics. He decided not to have the orthodontic treatment.

2. Anesthetic-In recent years, articaine has monopolized local anesthetic use in dentistry, and rightfully so. It is faster, more profound, and requires less solution quantity to afford optimum local anesthesia. Infiltration delivery is adequate for almost all veneer tooth preparations and seating.

3. Tissue management-In the past, many veneers had stains occur around the margins after a few years of service. I have observed this numerous times on patients referred to my practice. However, I have not had this occur frequently on veneers we have placed. My observation is that placement of nonchemically impregnated cords at the time of impressions and especially at the time of seating reduces or eliminates this problem. For most situations, No. 2 cord is adequate. Ultradent Products Ultrapak cord is shown in the photo (figure 3).



Figure 3: Cord placement at tooth preparation can ensure an adequate impression. Cord placement at seating similarly reduces or eliminates contamination by saliva, periodontal fluid, or blood, and unsightly staining during service is nearly eliminated.

4. Tooth preparation-Veneers have evolved through "no-prep" veneers, veneer preps all in enamel, and veneers deeply cut into dentin. Although no-prep veneers work well on small teeth, teeth in lingual version, spaced teeth, and some superficially pitted or discolored teeth, preps primarily in enamel have proven to be the most adequate for the majority of cases. Preparations more than 50% in dentin have a poor success rate since many debond in service in spite of company claims for high bond. Enamel bonding is dependable, and dentin bonding has proven to be variable and often inadequate (figures 4 and 5).

 



Figure 4: Three levels of tooth preparation are shown. The pitted teeth were restored with no-prep veneers. The preps in enamel have already had the veneers on them serve for 15 years. The deeply cut veneer preps done by another dentist were the subject of a lawsuit after they came off one by one during service. Avoid veneers placed on preparations that are more than 50% in dentin.



Figure 5: The tooth preparations for the teeth shown in figures 1 and 2 presented a significant challenge to provide tooth repositioning and color change. With the exception of the off-color central incisor, they are almost all prepared into enamel only.

5. Impressions-Polyvinyl siloxane or polyether impression materials provide highly accurate, proven, easy-to-accomplish, fast, and predictable impressions. I prefer double-arch impressions for one or two veneers and full-arch impressions for more than two restorations. Although some practitioners accomplish scanning for veneer impressions, it is not as common as scanning for crowns.

6. Provisional restorations-Most dentists use bis-acryl resin such as Luxatemp, Protemp Plus, and many other brands. The most common method for provisional fabrication is to:

a. Make a preoperative cast

b. Change any needed contour on the cast by placing some old or expired composite resin on the dry cast

c. Make a suck-down template over the modified cast

d. Trim the template

e. Try the template onto the prepped teeth

f. Place the appropriate color of bis-acryl resin in the template

g. Seat the loaded template onto the tooth preparations

h. Let the resin set

i. Trim the provisional

j. Seat the provisional on the preps with only a 2 mm or 3 mm round spot acid etched in the center of the facial surface of each prep for retention

The provisional cement is usually Temp-Bond Clear from Kerr, or newer brands such as ClearTemp LC from Ultradent. I suggest appointing the patient as soon as possible after the preps to avoid the provisional restorations coming off.

7. Veneer material-Almost all ceramic veneers placed at this time have changed from fired feldspathic or pressed leucite reinforced glass (IPS Empress) to IPS e.max. This material is much stronger than previous materials. It may be milled or pressed, it etches well with hydrofluoric acid, and the bond of the resin cement to the ceramic is enhanced easily with silane. This ceramic material is an important advancement in this technique (figures 6 and 7).

 



Figure 6: Note that the lateral incisors were restored in a facial position to make the smile appear harmonious and normal.



Figure 7: The final veneers were milled from IPS e.max multicolored blocks by Archibald Associates (Orem, Utah) and placed by me. Note the realistic appearance and attractive color variation including translucence. These veneers should serve for many years.

8. Seating the veneers-In the past, some teeth restored with veneers have had significant postoperative sensitivity, especially those placed on exposed dentin. This is a painful and frustrating situation for both patients and dentists. Significant research at Clinicians Report Foundation has proven that two one-minute applications of 5% glutaraldehyde/35% HEMA virtually eliminates postoperative tooth sensitivity without compromising the bond of the resin cement to tooth structure. Popular products are G5, GLUMA, Glu/Sense, MicroPrime, and Telio CS Desensitizer. Almost every major company producing composite resin has resin cement for veneers. Select your favorite, since they are very similar.

Summary

The techniques, materials, and concepts for ceramic veneers have changed significantly in the last few years. They are now among the most desirable, beautiful, and long-lasting techniques dentistry has to offer.


Gordon J. Christensen, DDS, MSD, PhD, is a practicing prosthodontist in Provo, Utah. He is the founder and director of Practical Clinical Courses, an international continuing-education organization initiated in 1981 for dental professionals. Dr. Christensen is a cofounder (with his wife, Dr. Rella Christensen) and CEO of Clinicians Report (formerly Clinical Research Associates).

Source : dentaleconomics.com