Head positioning in a cone beam computed tomography unit and the effect on accuracy of the three-dimensional surface mode.

Head position during cone beam computed tomography (CBCT) examination can easily deviate from the ideal, which may affect the accuracy of the segmented three-dimensional (3D) model. The aim of this study was to determine the effect of head positioning on the accuracy of the 3D model. A human dry skull was positioned at predetermined orientations in a CBCT scanner and scanned in multiple orientations and voxel sizes.

The use of platelet-rich plasma combined with demineralized freeze-dried bone allograft in the treatment of periodontal endosseous defects: a report of two clinical cases.

Background: On the basis of systematic reviews and randomized controlled trials, the authors provide reports of two cases in which platelet-rich plasma (PRP) combined with demineralized freeze-dried bone allograft (DFDBA) was used to treat periodontal endosseous defects.

Case Description: Clinicians treated two circumferential endosseous defects with a probing pocket depth of 5 and 8 millimeters, respectively (case 1), and a combined 1-2-3-wall endosseous defect with a probing pocket depth of 6 mm (case 2) by using the combination of PRP and DFDBA. At six months, complete periodontal pocket resolution occurred in all defects, and clinical attachment level and radiographic defect fill in all defects exhibited significant improvement compared with presurgical values.

Treatment of periodontal endosseous defects with platelet-rich plasma alone or in combination with demineralized freeze-dried bone allograft: a comparative clinical trial.

Background: Platelet-rich plasma (PRP) alone or combined with other regenerative materials was previously studied in human periodontal endosseous defects. There are no sufficient data evaluating to what extent the addition of demineralized freeze-dried bone allograft (DFDBA) to PRP may enhance the effectiveness of PRP. The aim of this randomized, double-masked, controlled clinical trial was to compare the effectiveness of autologous PRP alone to PRP + DFDBA in periodontal endosseous defects.

Radiation dose reduction in direct digital panoramic radiography.

Objectives: (a) To measure the absorbed radiation doses at 16 anatomical sites of a Rando phantom and (b) to calculate the effective doses including and excluding the salivary gland doses in panoramic radiography using a conventional and a digital panoramic device.

Study Design: Thermoluminescent dosimeters (TLD-100) were placed at 16 sites in a Rando phantom, using a conventional, Planmeca Promax and a digital, Planmeca PM2002CC Proline 2000 (Planmeca Oy, 00880 Helsinki, Finland) panoramic device for panoramic radiography. During conventional radiography the selected exposure settings were 66 kVp, 6 mA and 16s, while during digital radiography two combinations were selected 60 kVp, 4 mA, 18 s and 66 kVp, 8 mA, 18s with and without image processing function.