Purpose: To evaluate the marginal and internal fit of endocrowns with different computer-aided design/computer-aided manufacturing (CAD-CAM) materials by measuring them with a stereomicroscope (μm). Materials and Methods: A mandibular first molar typodont tooth was prepared to receive an endocrown. The preparation was scanned using an extra-oral scanner. Endocrowns ( n = 20) were fabricated using lithium disilicate (IPS e. max CAD LT block; CEREC Ivoclar Vivadent, Liechtenstein) and polyetheretherketone (PEEK) (breCAM. BioHPP ® ; Bredent, UK) using CAD-CAM technique. Marginal gap was evaluated using a stereomicroscope at the midpoint of all four surfaces (mid buccal, mid lingual, mid mesial, mid distal). This was followed by sectioning of the endocrowns in a sagittal plane along with the prepared tooth to evaluate the internal fit at four different points (A, B, C, D) using a stereomicroscope. Statistical analysis was performed using one-way analysis of variance test. Results: Mean values of marginal gap of lithium disilicate and PEEK endocrowns are 56.6 ± 6.1 μm and 81.3 ± 10.1 μm, respectively. Mean value internal gaps of lithium disilicate and PEEK endocrowns are 158.2 ± 11.1 μm and 199.1 ± 13 μm, respectively. Results in the present study have shown that the marginal and internal fits of lithium disilicate endocrowns are superior to that of PEEK endocrowns. Conclusions: Based on the outcomes of this in vitro study, the marginal and internal fit of lithium disilicate endocrowns is better than PEEK endocrowns. The marginal gap clinically acceptable is <120 μm. The marginal gap values recorded in this study are within the acceptable range for both materials.

Purpose: To assess the location of posterior superior alveolar artery (PSAA) using CBCT in relevance to sinus lift procedure for implant placement. Patients and Methods: A retrospective study was conducted using the CBCT data of 500 patients (n = 500). Linear measurements were carried out to localize the medio-lateral and vertical position of posterior superior alveolar artery in postero-lateral wall of maxillary sinus and its proximity to the floor of maxillary sinus using CS 3D imaging 3.7.0 software program. The relative position of PSAA was determined as; (a) intra-osseous, (b) below the membrane and (c) outer-cortex of lateral sinus wall. The location of PSAA was assessed in molar region bilaterally by using following radiographic measurement; (1) distance between the lower border of posterior superior alveolar artery and alveolar crest, (2) height from the floor of maxillary sinus to alveolar crest and (3) distance from the posterior superior alveolar artery to medial wall of maxillary sinus. Results: The prevalence of the artery was observed in 99.4% of the sinuses and was mostly intraosseous (84.2%).The mean distance between the lower border of the artery and alveolar crest is significantly higher in males compared to females (P < 0.01). The distribution of artery location did not differ significantly across various age groups (P > 0.05). Discussion/Conclusion: The most common variant of PSAA was identified in the intra-osseous region and the mean distance of the vessel to crest of the residual ridge differs significantly with gender and not with age.

The outcomes of anterior implant restorations are governed by the position and stability of the implant, the contours of the soft tissue and the type of final restoration. Flap design plays a crucial role for the success of guided bone regeneration procedures at the time of implant placement. In this case report two patients were treated for single tooth replacement in the aesthetic zone by means of an implant supported prosthesis. Treatment included a crestal incision followed by a trapezoidal flap elevation in one patient and triangular flap elevation in the other patient. Clinical and radiographic assessment using CBCT of both the subjects confirmed a deficiency of labial plate; thereby requiring guided bone regeneration at the time of implant placement. Screw-retained provisional restoration was used to achieve a desirable emergence profile, followed by placement of a cemented crown six months thereafter. Patients were clinically and radiographically reexamined after intervals of one week, three months and one year to assess implant survival and complications; hard and soft tissue outcomes. It can be concluded that triangular flap yields better aesthetic soft tissue outcomes when compared with a trapezoidal flap in anterior implant restoration following guided bone regeneration.

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