Clinical photon-counting CT (PCCT) offers a spatial resolution of about 200 µm and might allow for acquisitions close to conventional dental CBCTs. In this study, the capabilities of this new system in comparison to dental CBCTs shall be evaluated. All 8 apical osteolysis identified in CBCT were identified by both readers in all three PCCT scan protocols. Mean visibility scores showed statistical significant differences for root canals(p = 0.0001), periodontal space(p = 0.0090), cortical(p = 0.0003) and spongious bone(p = 0.0293) in favor of high and medium dose PCCT acquisitions. Overall, both devices showed excellent image quality of all structures assessed. Interrater-agreement showed high values for all protocols in all structures. Bland–Altman plots revealed a high concordance of both modalities with the reference measurements. In vitro, ultra-high resolution PCCT can reliably identify different diagnostic entities and structures relevant for dental diagnostics similar to conventional dental CBCT with similar radiation dose. Acquisitions of five cadaveric heads were performed in an experimental CT-system containing an ultra-high resolution PC detector (0.25 mm pixel size in isocenter) as well as in a dental CBCT scanner. Acquisitions were performed using dose levels of 8.5 mGy, 38.0 mGy and 66.5 mGy (CTDI16cm) in case of PCCT and of 8.94 mGy (CTDI16cm) in case of CBCT. The quality of delineation of hard tissues, root-canals, periodontal-space as well as apical osteolysis was assessed by two readers. Mean visibility scores and interrater-agreement (overall agreement (%)) were calculated. Vertical bone loss (bl) and thickness (bt) of the buccal bone lamina of 15 lower incisors were measured and compared to reference measurements by ore microscopy and clinical probing.

To investigate the image quality of a low-dose dental imaging protocol in the first clinical photon-counting computed tomography (PCCT) system in comparison to a normal-dose acquisition in a digital volume tomography (DVT) system. Clinical PCCT systems offer an increased spatial resolution compared to previous generations of clinical systems. Their spatial resolution is in the order of dental DVT systems. Resolution-matched acquisitions of ten porcine jaws were performed in a PCCT (Naeotom Alpha, Siemens Healthineers) and in a DVT (Orthophos XL, Dentsply Sirona). PCCT images were acquired with 90 kV at a dose of 1 mGy CTDI_16cm. DVT used 85 kV at 4 mGy. Image reconstruction was performed using the standard algorithms of each system to a voxel size of 160 × 160 × 200 µm. The dose-normalized contrast-to-noise ratio (CNRD) was measured between dentine and enamel and dentine and bone. Two readers evaluated overall diagnostic quality of images and quality of relevant structures such as root channels and dentine. CNRD is higher in all PCCT acquisitions. CNRD is 37% higher for the contrast dentine-enamel and 31% higher for the dentine-bone contrast (p<0.05). Overall diagnostic image quality was higher for PCCT over DVT (p<0.02 and p<0.04 for readers 1 and 2). Quality scores for anatomical structures were higher in PCCT compared to DVT (all p0.64). PCCT provides an increased image quality over DVT even at a lower dose level and might enable complex dental imaging protocols in the future. The evolution of photon-counting technology and it's optimization will increasingly move dental imaging towards standardized 3D visualizations providing both minimal radiation exposure and high diagnostic accuracy.

Objectives: There is little evidence about the effect of different treatment protocols for grade 3 endo-periodontal lesions without root damage in patients with periodontitis according to the new classification of periodontal disease. The aim of this study is to evaluate the impact of endodontic treatment on the achievement of periodontal healing. Materials and methods: Teeth with the initial diagnosis endo-periodontal lesion without root damage grade 3, treated with a standardized endodontic treatment protocol, were included in this study. A retrospective analysis was performed to assess the impact on periodontal healing by evaluating probing pocket depth (PPD), clinical attachment gain (CAL), and periapical index score (PAI). Results: Nineteen teeth and 13 patients were included. A mean reduction of 3.19 ± 3.41 mm in PPD was recorded. The mean CAL gain was 2.33± 3.75 mm. Five teeth (45.4%) showed an improvement of PAI and were classified as treatment success. Conclusions: The results failed to show a highly predictable treatment outcome for endo-periodontal lesion grade 3 without root damage in patients with periodontitis. However, endodontic therapy alone resulted in treatment success for some of the teeth, which would otherwise have had a poor prognosis. Clinical relevance: Endo-periodontal lesions can often be challenging for dentists in daily clinical practice. To date, there is not much evidence for practitioners to rely on. Therefore, this study aims to strengthen the evidence for the management and treatment of endo-periodontal lesions. Although the outcome is not highly predictable yet, teeth with the initial diagnosis endo-periodontal lesion without root damage grade 3 can benefit from an endodontic treatment.

Aim: To compare the Oral Health‐Related Quality of Life (OHRQoL) of patients with mobile mandibular incisors before and after full‐mouth disinfection (FMD) with and without splinting.Material and methods: Thirty‐four periodontitis patients with ≥1 mobile mandibular incisor (degree II/III) were randomly allocated to the test or control group. All patients received FMD and the test group additional splinting of teeth 33–43. OHRQoL was assessed before (BL) and 3 months after FMD (RE) using the Oral Health Impact Profile (OHIP)‐14. Data were compared within and between the groups (Wilcoxon test/Mann–Whitney U test).Results: Twenty‐eight patients (13 test group/15 control group) were re‐evaluated. FMD led to a reduction of the mean probing pocket depth (PPD; in mm) (test group: BL‐PPD 3.89 ± 1.03, RE‐PPD 2.82 ± 0.53; control group: BL‐PPD 3.58 ± 0.66, RE‐PPD 2.77 ± 0.59; each p ≤ .001), the mean clinical attachment level (CAL; in mm) (test group: BL‐CAL 5.22 ± 1.38, RE‐CAL 4.79 ± 0.85; control group: BL‐CAL 4.58 ± 1.10, RE‐CAL 4.41 ± 0.96; each p ≤ .05), and the mean OHIP‐14 summary scores (test group: BL‐OHIP 21.7 ± 11.06, RE‐OHIP 9.9 ± 8.96, p = .0046; control group: BL‐OHIP 16.8 ± 8.27, RE‐OHIP 11.7 ± 8.55; p = .0217). The reduction of the OHIP‐G14 scores was considerably higher in the test group but statistically not significant (p = .080).Conclusions: The results show a positive impact of non‐surgical periodontal treatment on OHRQoL and a possible tendency for further improvement by splinting mobile mandibular incisors.