Effect of the adhesive application mode and fiber post translucency on the push-out bond strength to dentin

This study evaluated the effect of the adhesive application mode and fiber post translucency on the push-out bond strength to dentin. Bovine roots were endodontically treated, and 10 roots were used for each adhesive application mode: PB (Prime&Bond 2.1), PB + SC (Self-cure activator), PB + SBM (Scotchbond Multi-purpose adhesive system), BB (Brush&Bond), BB + CAT (chemical catalyst), and BB + SBM. The translucent Light-Post and Aestheti-Post were cemented. The roots/cemented posts were transversally sectioned to originate three thirds (cervical, middle, and apical). The push-out test was performed, and the failure mode of fractured specimens was analyzed. There was no difference between the fiber posts. For PB and BB, the use of hydrophobic adhesive resin SBM increased post bond strength. The use of SC and CAT catalyst did not affect the push-out bond strength values. The apical third presented the lowest bond strengths.     

Flow of gingival exudate as related to menstruation and pregnancy

The gingival condition of i4 young women was studied through 3-4 consecutive menstrual cycles. The gingivae were scored according to Gingival Index system and gingival exudate was assessed at regular intervals during the experimental period. The results showed that the menstrual cycle was without effects on the state of the clinically normal gingiva. However, pre-existing gingivitis seemed to aggravate during menstruation. The mean flow of exudate from normal gingiva corresponded to that of a control group consisting of 16 young men, indicating that the menstrual cycle did not affect the flow of gingival fluid from normal gingiva. An additional series of exudate measurements on 42 women during pregnancy and post partum showed that gestation did not influence the flow of fluid from normal gingiva.     

Classification and prevalences of plaque streptococci after two years oral use of chlorhexidine

The purpose of the present study was to examine the influence of two years daily oral use of chlorhexidine (Löe et al. 1976) on the distribution of different streptococcal types in dental plaque. Plaque samples were collected from the molars in 16 persons in the chlorhexi dine group and from 17 control persons having used placebo solution. The samples were homogenized in yeast extract, and dilutions plated on mitis salivarius agar incubated micro aerophilically for 24 hours followed by aerobic storage at room temperature for 24 hours.
Colonies of each morphological type present were counted on plates having 30–300 colonies and their number related to the total number. One colony of each type was isolated and identified by biochemical tests. The study showed that 84.8 % of the strains could be classified as S. mutans, S. sanguis, S. mitior, S. milleri, S. salivarius , a group intermediary to S. sanguis and S. mitior , and a group resembling S. milleri , using only five biochemical tests: production of extracellular polysaccharide from sucrose, fermentation of mannitol, raffinose and inulin, and hydrolysis of esculin. In the chlorhexidine group the prevalences of S. sanguis and the group of streptococci intermediary to S. sanguis and S. mitior were higher, and the prevalence of S. milleri plus streptococci resembling S. milleri lower, among the streptococcal flora in dental plaque than those observed in the control group.     

Congenital infantile fibromatosis of the cheek: report of a rare case and differential diagnosis

Infantile fibromatosis is a benign tumour that consists of dense masses of fibroblasts and myofibroblasts with marked collagen production. Although it is a nonmetastasising tumour, it has significant potential for local invasion and recurrence and may be fatal because of its size and location. The authors report an unusual case of infantile fibromatosis of the cheek in an 8-month-old boy, present since birth. The patient underwent surgical treatment with tumour-free margins and the 6-month follow-up revealed no signs of recurrence. Infantile fibromatosis of the cheek is a very rare condition at this location, especially congenital cases. It should be considered in the differential diagnosis of congenital lesions in childhood.     

Water permeability,hybrid layer long-term integrity and reaction mechanism of a two-step adhesive system

Objectives

Our aim was to investigate the reaction mechanism of formation of the hybrid layer by a HEMA-containing self-etch adhesive and to study fluid filtration, contact angle and interfacial ultrastructure by SEM following a 1 year ageing period.

Methods

Acidic behaviour and chemical interactions between Silorane System Adhesive and dentine were studied by potentiometric titrations, atomic absorption spectroscopy and infrared spectroscopy. The hydrophilicity of the adhesive was evaluated using the sessile drop method and dentine permeability by hydraulic conductance. The morphological study of the dentine/adhesive system interface was conducted using SEM.

Results

The Silorane System Adhesive behaved as a multi-acid with several different pK_a values. When the adhesive was in contact with dentine, the acid was progressively consumed and calcium ions were released. The acrylate substituted phosphonate bound strongly to apatite crystals. The polyacrylic acid copolymer reacted with calcium ions and formed an interpenetrating polymer network (IPN). Water contact angle measurements showed rapid spreading on primer (angles reached 15° at 30 s) and larger contact angles when the Silorane bonding layer was added (from over 60° to 44°). A thick, homogeneous hybrid layer was observed both initially and after 1 year of ageing, with a corresponding hydraulic conductance of −48.50% initially and −52.07% at 12 months.

Conclusion

The Silorane System Adhesive is capable of both dissolving calcium ions and binding to apatite surfaces. The results showed the hydrophilicity of the adhesive, which formed an IPN-like hybrid layer that conserved adequate impermeability over a 1-year period.     

The efficacy of Xialine<Superscript>®</Superscript> in patients with Sjögren’s syndrome: a single-blind,cross-over study

Sjögren syndrome (SS) is a chronic inflammatory autoimmune disease of unknown cause whose main characteristic is severe dryness of the eyes and the mouth. The decreased functional capacity of the lacrimal and salivary glands which is the result of the inflammatory process and lymphocytic infiltration observed in SS is accountable for this complication. Twenty-nine patients with SS whose ages were ranging between 24–77, who were under treatment in Ege University Faculty of Medicine Department of Rheumatology, participated in the study, and their informed consents were obtained upon enrollment. Each patient recorded their subjective complaints on a separate questionnaire. The baseline and subsequent evaluation of the subjective findings on predetermined times (1 h after application of the material, at the end of the 1st, 7th, and 14th days) were also recorded on separate questionnaire sheets. Throughout the 14-day treatment period, no statistically significant differences were noted between the Xialine® and placebo groups with regard to burning tongue, diminished taste, and waking up at night to sip water (p?=?0.925, 0.527, and 0.066, respectively). However, patients’ satisfaction with placebo decreased by 25.63% at the end of the test period, whereas it increased by 16.37% after Xialine® administration. Overall, the patients preferred Xialine® at the end of the study (p?=?0.011). The main motive to administer saliva substitute is to improve lubrication and hydration of oral tissues. The results of this study indicated that Xialine® is helpful in the management of xerostomia-related symptoms of SS patients. However, further investigations in larger scale group of patients are recommended to provide the effects of these agents on various complaints of xerostomia.     

Molar Distalization with Different Pendulum Appliances: In Vitro Registration of Orthodontic Forces and Moments in the Initial Phase

Abstract. Aim: Registration of the orthodontic forces and moments acting with different types of pendulum appliance for non-compliance upper molar distalization in an in vitro study. Material and Methods: The purpose-designed test set-up comprised the following components: artificial maxilla with anchorage unit and two electrothermodynamic (ETD) molars, electronic measuring unit for temperature control and regulation, and a sensor unit with force-moment sensor, analog/digital converter and data readout unit. This set-up permitted virtually authentic simulation of in vivo conditions on the one hand and precise determination of the force systems on the other.The appliances investigated were the standard pendulum appliance with U-loop activation according to Hilgers and with uprighting activation according to Byloff, the M-pendulum with U-loop activation according to Scuzzo, and the Pendulum K with initial uprighting activation, toe-in bend and incorporated distal screw according to Kinzinger. Results and Conclusions: The effects shown by the standard pendulum appliance and the M-pendulum over a 3 mm simulated distalization increment were a marked decrease in the distally directed forces, and an increase in the intrusive and palatally directed forces as well as in the distoinclinatory, mesially inward, and palatally rotating moments.Activations in the U-loop region of the pendulum springs induced an increase in distally and buccally directed forces and in uprighting and buccally rotating moments as well as a marked rise in extrusive forces. Whereas the activation described by Hilgers led to mesially outward rotating moments, activation according to Scuzzo resulted in a further increase in the mesially inward rotating moments.In the measured standard pendulum appliances, uprighting activation at the end of the pendulum according to Byloff led to an increase in distally and buccally directed as well as in mildly intrusive forces, and to an increase in uprighting as well as in buccally and mesially outward rotating moments.With the Pendulum K according to Kinzinger, the initial toe-in bend and uprighting activation in the region of the end of the pendulum spring together with regular adjustment of the incorporated distal screw permitted virtually translatory molar distalization: constantly distalizing forces with slight intrusive, buccally directed, and rotating side effects.     

Effects of bilateral upper first premolar extraction on the mandible

The purpose of this study was to evaluate the effects of bilateral upper premolar extraction on mandibular growth. Twenty-six subjects (eight males, 18 females) in maximum pubertal growth with an Angle Class II molar relationship, normal to mild overjet increase, mild or no lower arch length discrepancy but severe upper arch discrepancy and no severe skeletal discrepancy were divided into two groups equal in number and gender, as extraction and control groups. The median chronological age was 11.2 years in the extraction group and 12.6 years in the controls. The subjects were observed for a median period of 1.1 years in the extraction group after bilateral extraction of the upper premolars and 1.2 years in the controls until termination of pubertal growth (DP3u) without any orthodontic treatment. Twenty-nine linear and angular measurements were made on 52 lateral cephalograms and hand-wrist radiographs taken before and after the study period. The increase in SNB measured on the total superimposition was significantly greater in the controls than in the extraction group (P < 0.05). In addition, anterior mandibular (counter-clockwise) rotation was only significant (P < 0.05) in the control group. Thus, it might be suggested that bilateral upper premolar extractions might affect the mandibular rotation tendency.