Purpose: This study evaluated how restorative materials-specifically, lithium disilicate (LD) (IPS e.max; Ivoclar Vivadent, Liechtenstein, Switzerland) and zirconia-affect the contrast-to-noise ratio (CNR) in cone-beam computed tomography (CBCT) imaging. Materials and Methods: CNR was compared between LD and zirconia (NexxZr T; Sagemax Bioceramics, Federal Way, USA; and Zirlux Transitions; Zahn Dental, New York, USA) using 2 CBCT machines-Planmeca ProMax 3D Mid 2015 (Planmeca, Helsinki, Finland) and PreXion 3D Excelsior (PreXion Inc., San Mateo, USA)-under multiple exposure settings, with and without metal artifact reduction (MAR). Four cylindrical ingots were scanned in a saline phantom under 10 conditions (Planmeca: Low, Normal, High, ±MAR; PreXion: Rapid, Standard, HD, UHD). CNR was calculated in ImageJ (National Institutes of Health, Bethesda, MD, USA) and analyzed with the paired t-test. Results: LD showed the highest CNR on Planmeca without MAR and across all PreXion settings. With MAR on Planmeca, zirconia outperformed LD. For zirconia, CNR improved with larger voxel sizes and MAR, whereas for LD it was optimal with smaller voxel sizes and MAR. Optimal Planmeca settings were Low (400 μm) + MAR for zirconia and High (150 μm) + MAR for LD. On PreXion, Rapid (200 μm) favored zirconia, while HD (100 μm) favored LD. Conclusion CBCT settings should be tailored to the restorative material, diagnostic need, and radiation dose. For zirconia, larger voxel sizes with MAR enhance CNR; for LD, smaller voxel sizes with MAR are optimal. Thesefindings support imaging optimization for patients with dental restorations.

Purpose: The aim of this study was to evaluate 3-dimensional cone-beam computed tomography (CBCT) images of alveolar bone changes in patients who underwent minimally invasive periodontal surgery-namely, the pinhole surgical technique (PST). Materials and Methods: Alveolar bone height was measured and compared on CBCT images of 254 teeth from 23 consecutive patients with Miller class I, II, or III recession who had undergone PST. No patient with active periodontal disease was selected for surgery. Two different methods were used to assess the alveolar bone changes postoperatively. In both methods, the distance between the apex of the tooth and the mid-buccal alveolar crestal bone on pre- and post-surgical CBCT studies was measured. Results: An average alveolar bone gain >0.5 mm following PST was identified using CBCT (P=0.05). None of the demographic variables, including sex, age, and time since surgery, had any significant effect on bone gain during follow-up, which ranged from 8 months to 3 years. Conclusion PST appears to be a promising treatment modality for recession that results in stable clinical outcomes and may lead to some level of resolution on the bone level. More long-term studies must be done to evaluate the impact of this novel technique on bone remodeling and to assess sustained bone levels within a larger study population.