High-Brightness Wavelength-Beam-Combined Eyesafe Diode Laser Stacks
At 1450 nm, we have demonstrated 20-W wavelength-beam-combined output from a 25- element single bar (M<sup>2</sup> ~ 1.9 times 10), and 80-W cw from a 6-bar diode stack (M<sup>2</sup> ~ 36 times 68).
Advances in high-brightness high-power semiconductor lasers
We present recent advances in high power semiconductor laser bars and arrays at wavelengths from the near infrared to the eye-safe regime including increased spectral brightness with internal gratings to narrow and stabilize the spectrum, increased spatial brightness with multimode and high power single mode performance, and reduced cost architectures from high power surface emitting 2-dimensional arrays. These devices have the potential to dramatically improve diode pumped systems and enable new direct diode applications.
Assessment of fractures in endodontically treated teeth restored with and without root canal posts using high-resolution cone beam computed tomography
Background Root fractures are a diagnostic challenge for dentists in endodontic treatment. This study aimed to determine the relationship between the characteristics of tooth fractures and the presence of root canal posts in endodontically treated teeth using high-resolution cone beam computed tomography (CBCT). Material and Methods Fifty high-resolution CBCT scans of endodontically treated teeth with a diagnosis of fracture were obtained, of which 30 were from women and 20 were from men. These scans were acquired with three Veraviewepocs 3D units and one 3D Accuitomo 170 unit, with a 40 × 40-mm field of view and 125 μm voxel size. The variables assessed included the type of fracture, extent of fracture, type of retention, post length, cause of endodontic failure, location of the lesion, and time required to detect the fracture (difficulty score). For data analysis, the chi-squared test, Student’s t-test, and multiple linear regression (α <0.05) were used. Results No association was found between the type of fracture and type of retention or between the type of fracture and its extent (P>0.05). On the other hand, the type of fracture significantly influenced the time required for its detection. Additionally, the most difficult plane for detecting the fracture and the difficulty score were associated, with statistically significant results. Conclusions The type of fracture in endodontically treated teeth was not associated with the type of post used for restoration. All of the CBCT systems used to detect tooth fracture showed the same efficiency. Key words:Cone-Beam CT, Tooth Fracture, Root Canal Post.