Dual stimuli-responsive FeO graft poly(acrylic acid)-block-poly(2-methacryloyloxyethyl ferrocenecarboxylate) copolymer micromicelles: surface RAFT synthesis, self-assembly and drug release applications.

Background: Stimuli-responsive polymer materials are a new kind of intelligent materials based on the concept of bionics, which exhibits more significant changes in physicochemical properties upon triggered by tiny environment stimuli, hence providing a good carrier platform for antitumor drug delivery.

Results: Dual stimuli-responsive FeO graft poly(acrylic acid)-block-poly(2-methacryloyloxyethyl ferrocenecarboxylate) block copolymers (FeO-g-PAA-b-PMAEFC) were engineered and synthesized through a two-step sequential reversible addition-fragmentation chain transfer polymerization route. The characterization was performed by FTIR, H NMR, SEC, XRD and TGA techniques.

Application of a wireless resonance frequency transducer to assess primary stability of orthodontic mini-implants: an in vitro study in pig ilia.

Purpose: The aim of the study was to evaluate whether resonance frequency analysis (RFA) using a wireless transducer can be used to assess the primary stability of orthodontic mini-implants.

Materials And Methods: Fifteen orthodontic mini-implants were placed in three ilium bone segments of country pigs. The wireless resonance frequency transducer was bonded to the head of the mini-implants, and RFA values of the mini-implants in bone were detected and converted into implant stability quotient (ISQ) values by the RFA monitor.

Comparison of self-tapping and self-drilling orthodontic mini-implants: an animal study of insertion torque and displacement under lateral loading.

Purpose: The aim of this study was to compare two types of orthodontic mini-implants, self-tapping and self-drilling, by measurement of the insertion torques and the displacements under lateral loading in an animal model.

Materials And Methods: After predrilling of host sites, 27 self-tapping and 27 self-drilling mini-implants were inserted in vitro in the ilia of country pigs. The axial drilling forces at each host site and the insertion torques during placement were recorded, and the displacements applied by variable lateral force (1 to 9 N) were measured.

Insertion angle impact on primary stability of orthodontic mini-implants.

Objective: To analyze the impact of the insertion angle on the primary stability of mini-implants.

Materials And Methods: A total of 28 ilium bone segments of pigs were embedded in resin. Two different mini-implant sizes (Dual-Top Screw 1.

Pre-drilling force and insertion torques during orthodontic mini-implant insertion in relation to root contact.

Background And Aim: The use of mini-implants for skeletal anchorage has greatly broadened the therapeutic spectrum in orthodontics over the last few years. The alveolar ridge is the most frequent insertion site, which however is associated with tooth injury, a risk not to be underestimated. The objective of this study was to examine the quantitative parameters of pre-drilling and implant insertion in association with the degree of a root contact.

Impact of implant design on primary stability of orthodontic mini-implants.

Aim: Skeletal anchorage with mini-implants has greatly broadened the treatment possibilities in orthodontics over the last few years. To reduce implant failure rates, it is advisable to obtain adequate primary stability. The aim of this study was to quantitatively analyze the impact of implant design and dimension on primary stability.

Stiffness and frictional resistance of a superelastic nickel-titanium orthodontic wire with low-stress hysteresis.

Introduction: Stress-induced martensite formation with stress hysteresis that changes the elasticity and stiffness of nickel-titanium (Ni-Ti) wire influences the sliding mechanics of archwire-guided tooth movement. This in-vitro study investigated the frictional behavior of an improved superelastic Ni-Ti wire with low-stress hysteresis.

Methods: Improved superelastic Ni-Ti alloy wires (L & H Titan, Tomy International, Tokyo, Japan) with low-stress hysteresis were examined by using 3-point bending and frictional resistance tests with a universal test machine at a constant temperature of 35 degrees C, and compared with the former conventional austenitic-active superelastic Ni-Ti wires (Sentalloy, Tomy International).

Unilateral horizontally impacted maxillary canine and first premolar treated with a double archwire technique.

A patient with a unilateral horizontally impacted upper left canine and first premolar was treated orthodontically. The use of a double archwire technique achieved the desired treatment goals. We discuss the problems associated with impacted maxillary canines and first premolars and the biomechanical interventions used for this patient.