In vitro bond strengths of resin modified glass ionomer cements and composite resin self-cure adhesives: introduction of an adhesive system with increased bond strength and inhibition of decalcification.

This study evaluated the shear bond strength and adhesive remnant index of 5 self-cure adhesives to comparatively evaluate a new adhesive system. Extracted human incisors were randomly divided into 7 test groups of 20 each. Incisor mesh-backed brackets were bonded to the tooth specimens in each group with their respective adhesive according to the manufacturer's instructions. The specimens were thermocycled for 2 weeks at temperatures from 5 degrees to 55 degrees C to simulate oral conditions and debonded using an Instron machine. Acceptable bond strength parameters were present with the Contacto No-Mix (composite resin containing glass ionomer 8.75 MPa) and Fuji Ortho SC with acid conditioning (6.98 MPa). Contacto No-Mix had a higher bond strength (11.2 MPa) when microetching and Megabond were employed than when these adjuncts were not employed. When FUJI Ortho SC specimens were conditioned with polyacrylic acid, they showed a higher bond strength (6.98 MPa) than when bonded to unetched teeth (5.41 MPa). In test 3, EXPT-fluoride adhesive (AF) demonstrated a higher bond strength (13.44 MPa) than both resin composite Contacto No-Mix (8.8 MPa, GAC 7.4 MPa) and FUJI Ortho SC (5.41 MPa). Expt AF (Test 3) and Concise had equal bond strengths, however, the former can potentially release fluoride from the glass ionomer. Although the Ex

Comparative assessment of light-cured resin-modified glass ionomer and composite resin adhesives: in vitro study of a new adhesive system.

The ideal adhesive system is one that prevents decalcifications and has sufficient bond strength to withstand untimely impact forces on bonded brackets. The purpose of this investigation was to study and compare the bond strengths and adhesive remnant indexes of light-cured resin-modified glass ionomer and conventional resin adhesives. A new light-cured resin-modified glass ionomer adhesive was compared with the conventional adhesive systems. The effects of the new adhesive, with a system of etching and using adhesive promoters on the tooth enamel, as well as microetching the brackets, were analyzed. Comparisons were made (analysis of variance and the Tukey method) between this and other adhesive systems. The new adhesive system is indicated where prevention of decalcification and increased bond strength in noncompliant patients are indicated.

Report of four familial cases with congenitally missing mandibular incisors.

Heredity is one of the possible factors associated with congenitally missing mandibular incisors. We report four cases--a mother and three daughters--in an attempt to examine this hypothesis. Different treatment modalities have been used to treat malocclusions stemming from this problem. The treatment philosophy of consolidating mandibular spaces and obtaining a stable occlusion, thereby preventing the removal of maxillary teeth or the use of a mandibular prosthesis, is presented.

Adhesion promoters, their effect on the bond strength of metal brackets.

There are occasions where it is desired to increase the bond strengths of no-mix adhesives. Noncompliant patients and hypocalcified and fluorosed tooth enamel require higher bond strengths than usually obtained. It was the purpose of this investigation to study the effects of adhesion promoters to increase bond strengths. In vitro shear bond strengths that use the Instron machine (Instron Corp., Canton, Mass.) and thermocycling methods indicate the bond strengths of a no-mix adhesive bonding 80 gauge metal mesh brackets can be significantly improved through the following techniques: control (MPa 9.0), sandblasting (MPa 10.8), sandblasting and silanating (MPa 11.9), Rocatec system (MPa 10.8), Kulzer "silicoating" (MPa 13.2), and adhesion promoters--Megabond--(MPa 13.3). These adhesive promoters have been and are clinically being tested with promising results.

A longitudinal study of the effects of surgery, radiation, growth hormone, and orthodontic therapy on the craniofacial skeleton of a patient evidencing hypopituitarism and a Class II malocclusion: report of a case.

Facial growth is an important factor for the orthodontists in the timing of treatment of the patient with a Class II malocclusion who has a potential for retarded growth. This patient had an isolated idiopathic growth hormone deficiency and hypothyroidism and was treated during a circumpubertal growth spurt in two phases. The first phase involved a functional appliance and the second was accomplished with fixed appliances. The case report affords one of the rare opportunities to document and analyze the multifactorial effects of surgery, radiation, growth and thyroid hormones, and orthodontic treatment on the craniofacial growth of a patient evidencing a Class II, Division 1 malocclusion (retrognathic mandible). Hand-wrist, panoramic, cephalometric radiographs, dental, and skeletal height and weight measurements are employed. Six-year posttreatment dental and craniofacial skeletal changes and management problems are presented as well.

Mucogingival orthodontic and periodontal problems.

The absence of keratinized gingiva alone is not an indication for a periodontal surgical procedure. However, if recession increases during orthodontic treatment, then a gingival graft may be indicated. Orthodontic therapy and removal of a mandibular incisor where excessive gingival recession is present may be the indicated treatment.

Treatment of compromised teeth: a multidisciplinary approach.

Treatment for uprighted abutment teeth that may have infrabony pockets can be considered complete when the following criteria are met: 1. The uprighted tooth is in its proper vertical axis. 2. There is a significant decrease in soft-tissue pocket depth. 3. Crestal leveling is evident radiographically. 4. Adequate space has been created to accommodate a pontic (minimally 6.5mm). The advantages of employing this orthodontic-periodontal technique are as follows: 1. Leveling of the osseous crest fosters pocket elimination obviating the necessity for removal of a great deal of supporting bone. Concomitantly, a significant decrease in pocket depth usually eliminated the need for periodontal surgery. 2. The resulting occlusal forces are placed in favorable axial inclinations. 3. There is an improved crown-to-root ratio, since the uprighted and extruded tooth is reduced to the level of the occlusal plane. This reduction is sufficient to improve considerably the prognosis of a questionable abutment tooth. 4. A pontic space is created for an esthetic and properly contoured pontic. 5. Parallelism is attained, so that the marginal integrity is more easily accomplished. 6. The orthodontic procedures are relatively uncomplicated, efficient, and esthetic, provided there is little or no lower anterior crowding. 7. The restorative dentist has a proper abutment tooth with a good prognosis for prosthesis.