Differences in Radiopacity, Surface Properties, and Plaque Accumulation for CAD/CAM-Fabricated vs Conventionally Processed Polymer-based Temporary Materials

Surface roughness, plaque accumulation, and cytotoxicity of provisional restorative materials fabricated by different methods

Fabricating method may affect the surface properties and biological characteristics of provisional restorations. This study aimed to evaluate the surface roughness, plaque accumulation, and cytotoxicity of provisional restorative materials fabricated by the conventional, digital subtractive and additive methods. Sixty-six bar-shaped specimens (2×4×10 mm) were fabricated by using provisional restorative materials through the conventional, digital subtractive and additive methods (n = 22 per group). Ten specimens of each group were used for surface roughness and plaque accumulation tests, 10 specimens for cytotoxicity assay, and 2 specimens of each group were used for qualitative assessment by scanning electron microscopy. The Ra (roughness average) and Rz (roughness height) values (μm) were measured via profilometer, and visual inspection was performed through scanning electron microscopy. Plaque accumulation of Streptococcus mutans and cytotoxicity on human gingival fibroblast-like cells were evaluated. The data were analyzed with one-way ANOVA and Tukey's post hoc test (α = 0.05). Surface roughness, biofilm accumulation and cytotoxicity were significantly different among the groups (P<0.05). Surface roughness was significantly higher in the conventional group (P<0.05); however, the two other groups were not significantly different (P>0.05). Significantly higher bacterial attachment was observed in the additive group than the subtractive (P<0.001) and conventional group (P = 0.025); while, the conventional and subtractive groups were statistically similar (P = 0.111). Regarding the cytotoxicity, the additive group had significantly higher cell viability than the subtractive group (P = 0.006); yet, the conventional group was not significantly different from the additive (P = 0.354) and subtractive group (P = 0.101). Surface roughness was the highest in conventionally cured group; but, the additive group had the most plaque accumulation and lowest cytotoxicity.

A Glass Fiber-Reinforced Resin Composite Splint to Stabilize and Replace Teeth in a Periodontally Compromised Patient

Combined periodontal and prosthodontic treatment demands of patients require a structured coordination of pretreatments and an adequate choice of restorations. This is especially true if multiple teeth are missing and insufficient crown-root ratios are obvious. A 40-year-old patient with a severe periodontitis (Stage IV, Grade C) was treated with active, nonsurgical periodontal therapy. Afterwards, a supportive periodontal therapy was provided with a recall interval of three to four months. Due to a high tooth mobility of the anterior teeth in the upper jaw and a missing left canine, a combination of a resin composite (Signum composite, Kulzer, Hanau, Germany) and a unidirectional glass prepreg fiber (Tender Fiber Quattro, MICERIUM, Avegno, Italy) was utilized to fabricate a splint in a labside approach to stabilize the remaining teeth. Moreover, an artificial denture tooth was adhesively luted to the splint. A temporary polymer-based material (Vita CAD-Temp, VITA Zahnfabrik, Bad Säckingen, Germany) was selected to supply the posterior teeth of the patient with a 3-unit fixed dental prosthesis (FDP), and both restorations were adhesively cemented. 19 months after insertion, a fracture of the fiber-reinforced resin composite splint occurred that was intraorally repaired. In spite of the fracture of the splint, all materials were functionally and esthetically stable over the follow-up period of 22 months.