Concerning the types of prostheses used in the posterior region (Q6) (Figure 3), PFM design accounts for about 40% of the total, although the questionnaire also revealed a trend (in 9.1% of all cases) toward metal occlusal designs to avoid fracture and chipping of the veneer material. The same trend is evident in indirect composite facing crowns, where metal occlusal designs are used in about 35% of all cases that this type of prosthesis represents. In the past, the PFM crown was frequently used in implant crowns and bridges. However, a trend is seen toward increasing indirect composite resin use as a veneer material for implant superstructures. In addition to improvements in the physical properties (strength, wear resistance, and discoloration resistance) of indirect composites in recent years, their selection as veneer materials that chemically bond to titanium against the backdrop of increasing CAD/CAM-designed titanium frameworks, because of the low reliability of veneering porcelain, in terms of bonding strength, when used with titanium frames. There is also a greater possibility of direct (in-mouth) repair of failed veneering materials and greater shock-absorbing potential relative to occlusal force in comparison with porcelain [39]. The trend to adhere resin materials instead of porcelain, from Brånemark and colleagues’ recommendations for acrylic resin as an occlusal surface material in the early 1980s, also cannot be ignored [40]. All metal crowns were used about 10.3% of the time in molar regions because of a lack of strong aesthetic requirements. Zirconia, however, accounted for 14.3%; only about half of its use in the anterior region. Possible reasons include this region not being an aesthetic area and veneer material fracture and chipping problems that have yet to be completely resolved [23,41,42].

Implant overdentures (IODs) (Table 3)

Some 19% of IOD design work is left to technicians, while 80% is performed according to the instructions of, or in consultation with, dentists (Q7). As was the case with the question concerning overall prosthesis design described above, these results indicate that a team approach is being put into practice.