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Clinical RelevanceBased on in vitro results in extracted teeth, the dual bonding method used was effective in restoring the shear bond strength values that decreased after applying provisional luting agent regardless of the composition of the provisional luting agent (eugenol-based or eugenolfree) used. SUMMARYThis study evaluated the effect of two different types of provisional luting agents (RelyX Temp E, eugenol-based; RelyX Temp NE, eugenol-free) on the shear bond strengths between human dentin and two different resin-based luting systems (RelyX ARC-Single Bond and Duo Link-One Step) after cementation with two different techniques (dual bonding and conventional technique). One hundred human molars were trimmed parallel to the original long axis, to expose flat dentin surfaces, and were divided into three groups. After related surface treatments for each specimen, the resin-based luting agent was applied in a silicone cylindrical mold (3.5 x 4 mm), placed on the bonding-agent-treated dentin surfaces and polymerized. In the control group (n=20), the specimens were further divided into two groups (n=10), and two different resin-based luting systems were immediately applied following the manufacturer's protocols: RelyX ARC-Single Bond (Group I C ) and Duo Link-One Step (Group II C). In the provisionalization group (n=40), the specimens were further divided into four subgroups of 10 specimens each (Group I N, I E and Group II N, II E). In Groups I N and II N, eugenolfree (RelyX NE), and in groups I E and II E, eugenol-based (RelyX E) provisional luting Operative Dentistry, 2007, 32-1, 84-93 agents (PLA), were applied on the dentin surface. The dentin surfaces were cleaned with a flourfree pumice, and the resin-based luting systems RelyX ARC (Group I N and E) and Duo Link (Group II N and E) were applied. In the Dual bonding groups (n=40), the specimens were divided into four subgroups of 10 specimens each (Group I ND, ED and Group II ND, ED). The specimens were treated with Single Bond (Groups I ND and ED) or One Step (Groups II ND and ED). After the dentin bonding agent treatment, RelyX Temp NE was applied to Groups I ND and II ND, and RelyX Temp E was applied to Groups I ED and II ED. The dentin surfaces were then cleaned as described in the provisionalization group, and the resin-based luting systems were applied: RelyX ARC-Single Bond (Group I ND and ED) and Duo Link-One Step (Group II ND and ED). After 1,000 thermal cycles between 5°C and 55°C, shear bond testing was conducted at a crosshead speed of 0.5 mm/minutes. One-way ANOVA, followed by a post hoc Tukey test (α α=0.05) was done. The dentin-resin-based luting system interfaces were evaluated under a scanning electron microscope. There was a significant reduction in the mean shear bond strength values of groups subjected to the provisionalization compared to the control and dual bonding technique groups (p<0.05). The composition of provisional luting did not create a significant difference with regard to reducing shear bond strength values (p>0.05). Wi...

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The aim of this study was to compare the effects of various porcelain surface-conditioning techniques, used either alone or in combination, on the shear bond strength (SBS) of ceramic brackets cured with a light emitting diode (LED). Thirty glazed porcelain facets were randomly divided into three groups of 10. In group I, the porcelain surfaces were etched with 9.6 per cent hydrofluoric acid (HFA) for 2 minutes before silane application, in group II, the porcelain surfaces were sandblasted with aluminium oxide particles, etched with 9.6 per cent HFA for 2 minutes, and silane applied, and in group III, the porcelain surfaces were sandblasted with aluminium oxide particles before silane application. Spirit ceramic brackets were bonded with a light-cured composite resin (Light Bond) and a LED. All specimens were stored in distilled water at 37 degrees C for 24 hours and thermocycled. Bond strength was determined in shear mode at a crosshead speed of 0.5 mm/minute until fracture occurred. Analysis of variance indicated a significant difference between groups (P < 0.001). The lowest SBS was found in group III (5.46 +/- 1.34, P < 0.001). No significant difference was found between group I (11.38 +/- 1.65) and group II (10.45 +/- 1.15; P > 0.05). Surface treatment with HFA and a silane coupling agent produced the highest bond strength. Sandblasting before HFA and silane application did not significantly increase bond strength. Silane application to sandblasted porcelain provided poor results in vitro and clinical trials are needed to determine its reliability for bonding ceramic brackets to ceramic crowns.

ABSTRACT"Conical tooth anomaly" is a hereditary and otosomal dominant disorder which usually effects the maxillary permanent lateral incisors and third molars. Sometimes, the other teeth can be affected by this anomaly. Generally, the affected teeth are smaller than normal sizes and usually show a conical form which may be peg, cylindrical, barrelshaped etc. "Conical tooth anomaly" is generally influenced by several genetic and environmental factors. This anomaly can give rise some physiological and psychological problems. So, early and accurated diagnosis and treatment planning are important for such functional, esthetic and orthodontic reasons. For treatment of this anomaly, composite or porcelain veneer restorations can be made and thus an ideal oral condition and pleasure of patient may be provide esthetically and functionally.In this case report, "the clinical and radiographic evaluations and diagnosis and conservative treatments with composite resin veneer restorations of three different patients with conical tooth anomaly" were reported.

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