Comparison of AudaxCeph®'s fully automated cephalometric tracing technology to a semi-automated approach by human examiners.

OBJECTIVE: To compare the reliability of cephalometric landmark identification by an automated tracing software based on convolutional neural networks to human tracers. MATERIALS AND METHODS: Sixty cephalograms were traced by two board-certified orthodontists and AudaxCeph®'s artificial intelligence software. The following thirteen landmarks were identified in each tracing: Sella, Nasion, A point, B point, Porion, Menton, Pogonion, Orbitale, Gonion, Upper Central Incisor Incisal Edge (U1 Tip), Upper Central Incisor Root Apex (U1 apex), Lower Central Incisor Incisal Edge (L1 Tip), Lower Central Incisor Root Apex (L1 apex). An x-y axis was positioned in the bottom left corner of each cephalogram, and the x- and y-coordinates for the landmarks were exported into Excel. Distributions of landmarks (X, Y, radial distance) were compared using t-tests of equivalence with a 2mm equivalence bound. These compared the AI position to the two orthodontists - and the orthodontists' reliability by comparing equivalence against each other. RESULTS: There was no statistical difference between the orthodontists and AudaxCeph®'s automatic tracing software except for the x- and y-dimension of Porion and the y-dimension of L1 apex. The two orthodontists had good intra-examiner reliability with no statistical difference found when comparing them. CONCLUSION: AudaxCeph®'s automated cephalometric tracing software is a good adjunctive tool to use when diagnosing and treatment planning orthodontic cases.

Comparison of tensile bond strength of new and rebonded Symetri Clear™ ceramic brackets with Transbond™ XT or BluGloo™, with or without surface treatment: An in vitro study.

OBJECTIVES: This study sought to determine the bond strength of the Symetri Clear™ bracket after rebonding (reused) for a second and third time. MATERIALS AND METHODS: Symetri Clear™ mandibular incisor brackets were bonded to bovine incisors and divided into six experimental groups. Two groups underwent tensile bond strength testing, and the remaining four groups were debonded using the manufacturer's recommended plier. Two groups were rebonded twice following surface preparation with Ortho SoloTM and two groups were rebonded twice without surface preparation. The rebonded brackets also underwent tensile bond strength testing after each rebonding event as well as receiving an Adhesive Remnant Index score. RESULTS: One-way ANOVA found a statistically significant difference in bond strength among the six groups (P<0.0001). Tukey's Studentized Range (HSD, honestly significant difference) Test found significant differences in tensile bond strength of groups which did not undergo surface preparation prior to rebonding. One-way ANOVA found a P-value of 0.2563 and thus no significant difference in ARI among the different groups. CONCLUSIONS: There was no significant difference in the tensile bond strength of Symetri ClearTM brackets initially bonded with either Transbond™ XT or BluGloo™ and no significant difference between the initial tensile bond strength and the first or second rebond tensile bond strength. Rebonding Symetri Clear™ brackets without surface treatment did show significantly reduced tensile bond strength.

Shear bond strengths of molar tubes bonded with different adhesives.

AIMS: This study determined which molar base retentive designs produced the greatest shear bond strength (SBS) to human molars when using different adhesives. METHODS: One hundred and fifty extracted human molars were divided into 15 groups of 10. The tested molar tube bases included two stainless steel experimental base designs, a titanium single mesh 80 gauge base, a stainless steel double mesh 150 gauge under 80 gauge base and a stainless steel single mesh 80 gauge base. Each base was bonded with Transbond XT, Pad Lock and Light Bond. One primer, Assure, was used for all specimens. Bonded specimens were stored in water for 7 days and SBS was measured on an Instron testing machine with a crosshead speed of 1 mm/minute. Two-way ANOVA were performed with post-hoc comparisons of the means to determine any statistical differences in SBS. The significance level was set at 5 per cent. RESULTS: The brackets, adhesives and combinations of brackets and adhesives used had a significant effect on SBS (Bracket: p < 0.001; Adhesive: p = 0.020; Interaction: p = 0.005). Mean SBS differed significantly for the adhesives: Light Bond, Pad Lock and Transbond (p < 0.001, p = 0.001 and p < 0.001, respectively). In general, the stainless steel single mesh 80 gauge base and Light Bond adhesive produced the greatest SBS. CONCLUSION: The clinician's choice of bracket and adhesive affect the SBS of bonded molar attachments.