Clinical Cases

Performance and practicality

Case by A/Prof Alan Yap, BDS (Syd), MDSc Hons (Pros)(Syd), FAANZP

Since 1983 PANAVIA™ by Kuraray Noritake Dental Inc. has been the gold standard for dental cements throughout the world. Their latest cement, PANAVIA™ Veneer LC, sets a new standard for porcelain veneer cements through incredible performance and ease of use. The following clinical case demonstrates the use of PANAVIA™ Veneer LC.

A 31-year-old female (Fig. 1) was referred for porcelain veneers to replace lost tooth structure and to improve aesthetics. The patient exhibited moderate attrition of her anterior and bicuspid teeth (Fig. 2), the result of nocturnal bruxism and a tendency to an edge-to-edge occlusion. She had a Class I malocclusion on a Skeletal Class I tending III base with the right maxillary canine in cross-bite. The treatment plan included orthodontic treatment, porcelain veneers, and an occlusal splint.

Fig. 1

Fig. 2

Orthodontic treatment (by Dr Nour Tarraf) included full-fixed appliances with TADs and IPR of mandibular anteriors, and arch retractions to reduce protrusion (Fig. 3, post-orthodontic treatment). A preliminary digital design (Fig. 4) was performed to guide the diagnostic wax-up and a digital mock-up (Fig. 5) was utilised to verify the diagnostic wax-up prior to carrying out the intra-oral mock-up. The patient was unable to afford the restoration of the maxillary bicuspids until a later stage so the reconstruction was limited to the maxillary anterior teeth.

Fig. 3

Fig. 4

Fig. 5

Using the diagnostic wax-up, silicone keys were fabricated to guide tooth preparations. Orthodontic treatment allowed prosthetic treatment to be additive in design which meant that tooth preparations could be conservative. Labial reductions were limited to 0.3 mm and incisal reductions were performed only where needed to create an incisal butt joint for the veneer (Fig. 6). Minimal preparations allowed the veneers to be bonded almost entirely to enamel, which is important for the long-term survival of porcelain veneers (Ref 1). There was no need to significantly mask the colour of the cervical region of the tooth and non-carious cervical lesions were absent, so fine chamfer margins were prepared at equi-gingival level.

Fig. 6

Splinted provisional veneers (Fig. 7) were fabricated using bisacryl ensuring sufficient interdental space to allow hygiene access for small interdental brushes. The labial surface of the provisional veneers were glazed with a unfilled resin and cemented using the spot-etch technique, ensuring all excess flowable composite was removed prior to curing (Fig. 8). Twice daily interdental cleaning of the provisional veneers and thorough brushing of labial margins during the provisional phase maintained soft tissue health, important for the try-in and cementation of the definitive veneers.

Fig. 7

Fig. 8

A dry try-in of the definitive veneers was performed to check the fit of the veneers and a wet try-in was performed using try-in paste to assess aesthetics. The PANAVIA™ Try-in pastes accurately mimic the cement shades. Four useful shades are available (Fig. 9). The White and Brown shades are useful to correct small discrepancies in shade requiring subtle increases or decreases in shade value respectively. Conveniently the try-in pastes are the same as the PANAVIA™ V5 range of try-in pastes (excluding opaque). Following the try-in procedure the teeth were isolated using rubber dam and the floss ligature technique. KATANA™ Cleaner (Fig. 10) was used to clean the veneers prior to silanating with CLEARFIL™ CERAMIC PRIMER PLUS (Fig. 11).

Fig. 9

Fig. 10

Fig. 11

Veneers that have not been pre-etched should be etched with hydrofluoric acid prior to silanization. The use of the ProsMate™ Baton allows the cleaning, etching and silanization of all veneers simultaneously (Fig. 12). The veneers are arranged systematically on the ProsMate™ Tray ready for the cementation procedure (Fig. 13). Tooth surfaces were pre-treated with phosphoric acid (K-ETCHANT Syringe) and PANAVIA™ V5 Tooth Primer (Fig. 14).

Fig. 12

Fig. 13

Fig. 14

The newly designed cement applicator tip reduces air bubbles and the wide 16-gauge tip (Fig. 15) allows light and easy control of cement extrusion while also providing efficient wide coverage during application. PANAVIA™ Veneer LC has excellent handling because of its ideal paste consistency. It is non-sticky and its viscosity prevents the cement from flowing beyond the veneer margins until the veneer is seated. It is not runny or stringy. Furthermore its thixotropic properties results in lower film thickness during seating of the veneer. These excellent handling properties are due to the development of new filler technology which consists of spherical silica and nano cluster fillers (Fig. 16). The “touch-cure” mechanism of PANAVIA™ V5 Tooth Primer importantly seals the bonding interface while the extended working time and stability of the cement under ambient light allows the simultaneous cementation of multiple veneers. In this case all six lithium disilicate veneers (technical work by Yugo Hatai) were cemented simultaneously with PANAVIA™ Veneer LC Paste (Clear).

Fig. 15

Fig. 16

Tack-curing each veneer for one second allowed smooth and easy bulk removal of excess cement with an explorer (Fig. 17). Remaining excess of uncured paste was removed with brushes. Final curing was performed by light curing lingual and labial surfaces.

Fig. 17

The optical characteristics of PANAVIA™ Veneer LC, use of fine chamfer margins, and well-fitting translucent restorations produces a gradual and smooth transition of colour from tooth to veneer where margins disappear and soft tissues respond in a healthy way (Fig. 18). The color stability, excellent abrasion resistance and high gloss durability of PANAVIA™ Veneer LC preserves integrity and aesthetics at the margins over the long term. The extraordinary bond strength of PANAVIA™ products, so familiar to our profession over the last 20 years, is still second to none (Fig. 19).

Fig. 18

Fig. 19

“KATANA” is a registered trademark or trademark of NORITAKE CO., LIMITED - “PANAVIA” and “CLEARFIL” are registered trademarks or trademarks of KURARAY CO., LTD.

References

1. Layton DM, Walton TR. The up to 21-year clinical outcome and survival of feldspathic porcelain veneers: accounting for clustering. Int J Prosthodont. 2012 Nov-Dec; 25(6):604-12. PMID: 23101040.