Cervical Contractions Research Articles

Effect of tooth storage and cavity cleansing on cervical gap formation in class II glass-ionomer/composite restorations

Class II cavities with the cervical margin just below the C-E junction and with two cervical retention grooves were prepared in intact human premolars, 31 cavities in teeth stored frozen and 29 cavities in teeth stored in 1% chloramine solution. The teeth from both storage conditions were assigned to two groups; in one group, the cavities were cleaned with a water spray, in the other group, with a cleaner containing 0.2% EDTA and 1% NaF. All cavities were lined with Vitrebond and restored with P50. Cervical contraction gaps were disclosed by a fluorescent resin penetration technique. The length and width of each gap were analysed. A contraction gap was revealed in 17 of the 31 cavities in teeth stored frozen (54.8%) and in 22 of the 29 restorations in the teeth stored in chloramine (75.8%). The width of the gap was significantly greater in teeth stored in chloramine (p = 0.0004). No statistical difference in gap formation was found between cavities cleaned with water or with the detergent containing 0.2% EDTA and sodium fluoride. Since the cavity cleansing procedure was not a significant factor in gap formation, apparently removing the superficial smear layer with the cavity cleaner does not impair the bonding of Vitrebond to the dentin. However, gap formation appeared to be significantly affected by the storage conditions of the extracted teeth. It is suggested that teeth to be used in bond strength and leakage experiments should be stored frozen rather than stored in 1% chloramine solution.

Reduction of cervical gaps in class II composite resin restorations

Class II cavities prepared in brass models and in extracted teeth were restored with three light-cured composite resins. A transparent cone-shaped device (Light-tip) at the end of the light source was pressed into the filling material in the proximal ☐ for curing the resin. A second layer was filled in the recess left by the cone and cured without the cone. Controls consisted of fillings cured in two layers. In the brass cavities the contraction gap was 10 μm (±10.6) with use of the cone compared with 109.5 μm (±46.5) in control fillings ( p < 0.001). Extracted teeth were restored without etching of the enamel. Cervical contraction gaps in control restorations were reduced by more than half with the use of the transparent cone technique.

Treatment of post burn cervical contractions

Treatment of post burn cervical contractions

The rigid and stenosed cervix in the first stage of labor

Etiology.—The great frequency with which fibrosis occurs as the cause of true primary cervical dystocia is indicated. Conclusive evidence of the presence of continuous circular fibers (sphincteric type) is not forthcoming. It seems that ordinarily the caliber of the canal is maintained passively by the anatomic conformation of the organ as in the case of other nonsphincteric orifices. Doubt is cast upon the existence of such a condition as “spasmodic cervical contraction” during labor. In cases where such a diagnosis has been most frequently made, there are very often psychic or other general factors which, on careful analysis, will prove to be the actual cause. Other factors which may occasionally cause a cervical dystocia are discussed: syphilis, displacement of the os, adhesive membranes, overlapped cervical lips, etc. The condition called “Conglutinatio Orificii Externi” is considered.Diagnosis.—In the diagnosis, extracervical factors must be eliminated and fibrosis should always be suspected. In its absence, the most frequent factors causing an apparent cervical dystocia are (1) a misinterpretation of the patient's reaction to the very early stages of labor, giving the impression of prolonged labor without commensurate cervical change. (2) Active voluntary resistance to descent occasioned by the pain consequent upon pressure on the cervix.Treatment.—If an apparent cervical dystocia is not due to fibrosis, the most favorable results will follow watchful expectancy and the advised use of sedatives. Such methods will decrease in efficiency in direct proportion to the degree of scar tissue involvement, but may be helpful in any case. The use of bleeding and the warm bath is discussed. The insertion of weighted bags where fibrosis is a factor is condemned. Manual dilatation is seldom advisable, and instrumental dilatation never. The correct use of incisions is advised and described. Vaginal and abdominal cesarean section are discussed.

Spasmodic cervical contraction and injury to the child's head during labor: Füth: Zeitschrift für Geburtshülfe und Gynäkologie, 1923, lxxxvi, 633

Spasmodic cervical contraction and injury to the child's head during labor: Füth: Zeitschrift für Geburtshülfe und Gynäkologie, 1923, lxxxvi, 633