Influence of fluoride- or triclosan-based desensitizing agents on adhesion of resin cements to dentin.

Effect of desensitizers on the bond strength of resin cements to dentin was evaluated. Intact premolars (N = 90) were embedded in polymethyl methacrylate; dentin surfaces were exposed, and they were randomly divided into two main groups of cements (Duolink (D), Variolink II (V); n = 45 per group) and then into three desensitizer subgroups (n = 15 per subgroup). Teeth in controls (C) were treated according to cements' adhesion protocols; the other two groups received either fluoride- [Aqua-Prep F (F)] or triclosan-based [Seal&Protect (T)] desensitizers. Ceramic disks (Empress 2) were adhered; specimens were thermocycled (×5,000 cycles, 5-55 ± 1°C, dwell time 30 s) and subjected to shear bond strength test (MPa ± SD) in a universal testing machine (crosshead speed 1 mm/min). Failure types were classified using scanning electron microscope. For V, application of both desensitizers (29.6 ± 7.8 and 22.8 ± 2.8 for F and T, respectively) did not present significantly different results than that of the VC (21.2 ± 2.3; p > 0.05, one-way ANOVA). In D, F (20.6 ± 2.4) showed significantly higher results (p < 0.05) than those in T (16.1 ± 3.9) and DC group (15.2 ± 2.3). V showed significantly higher results than D (p < 0.05, Bonferroni). F and T did not negatively affect the bond strength results with D and V. Adhesive failures were more frequent with both T (84%) and F (66%) in D; cohesive failures in the cement (88%) were more commonly observed with F in V. Both F and T desensitizers can be safely used prior to final cementation but F in combination with V seems to be more reliable, considering both the bond strength and the failure types.

Bond strength comparison of amalgam repair protocols using resin composite in situations with and without dentin exposure.

The replacement of defective amalgam restorations leads to loss of tooth material and weakens the tooth, creating an increased risk of cusp fracture. The repair of such defects is a minimal intervention technique. The current study compared the repair bond strengths of a resin composite to amalgam and an amalgam-dentin complex after various surface conditioning methods. The specimens (N = 50) consisted of sound human canines with cylindrical preparations (diameter: 2.3 mm, depth: 3 mm) with amalgam-dentin complex (N = 30, n = 10/per group) and two groups with amalgam only (N = 20, n = 10/per group). The teeth were embedded in auto-polymerized polymethylmethacrylate (PMMA). The preparations were filled with non-Gamma 2 amalgam. The enamel was removed to expose dentin. The specimens with the amalgam-dentin complex were randomly assigned to one of the following conditioning methods: Group 1: Silicacoating amalgam, etching dentin, silane application on amalgam, primer/bonding on dentin, opaquer on amalgam, resin composite on both; Group 2: Etching dentin, silicacoating amalgam, silane application on amalgam, primer/bonding on dentin, opaquer on amalgam, resin composite on both and Group 3: Etching dentin, primer/bonding on dentin, opaquer, resin composite. The specimens with only amalgam were assigned to one of the following conditioning methods: Group 4: Silicacoating, silane application, opaquer, resin composite and Group 5: Opaquer, resin composite. For the two control groups, where no dentin was involved (Groups 4 and 5), bonding was achieved only on amalgam and Group 5 had no conditioning. The specimens were kept in water at 37 degrees C for five weeks before bond strength (MPa +/- SD) testing (Universal Testing Machine). After debonding, the failure types were analyzed. The results were significantly affected by the surface conditioning method (ANOVA). Only dentin conditioning (Group 3) showed the highest bond strength (39.9 +/- 14). The unconditioned control group (Group 5) showed the least favorable results (1.4 +/- 0.5). Multiple comparisons (Tukey-Kramer adjustment) showed that the mean values of Group 1 (34.1 +/- 11.4), 3 (39.9 +/- 14) and 4 (35.5 +/- 4) were not significantly different (p > 0.05), but between Groups 2 (22.8 +/- 6.6) and 3 (39.9 +/- 14), significant differences were observed (p = 0.0027). For reliable repair of amalgam restorations, including dentin fractures, the amalgam surface should first be silica coated, then the dentin/enamel should be etched, washed and rinsed thoroughly. Finally, the amalgam should be silanized and primer/bonding applied onto the dentin.

Reversal of reduced bond strength after bleaching.

This article investigated how the shear bond strength of a luting resin to dentin was affected by antioxidant treatment and delayed bonding after bleaching with carbamide peroxide. Using a lowspeed diamond saw, 40 flat dentin surfaces were prepared from freshly extracted human molars and divided into three bleaching groups (n = 10) and a control group (n = 10). Group 1 consisted of specimens bonded immediately after bleaching. Group 2 specimens were treated with an antioxidant agent (10% sodium ascorbate), while Group 3 specimens were immersed in artificial saliva for one week after bleaching. Specimens in Group 4 were not bleached but were immersed in artificial saliva for one week before bonding. Forty ceramic blocks were prepared and luted to teeth using a dual-curing resin cement. The specimens were thermocycled and the shear bond strength tests were performed using a universal testing machine. Fracture analysis was performed using a scanning electron microscope. While the Group 1 samples demonstrated the lowest shear bond strengths (11.9 +/- 3 MPa) (p < 0.05), no significant differences were found among samples in Group 2 (26.3 +/- 7.1 MPa), Group 3 (20.7 +/- 6.5 MPa), and Group 4 (22.1 +/- 2.5 MPa) (p = 0.05).

Prosthetic rehabilitation of hemimandibular hyperplasia: five-year follow-up.

Hemimandibular hyperplasia is a rare asymmetrical mandibular malformation, characterized by enlargement of the condyle, the condylar neck, the ramus, and the body of the mandible. This condition results in laterognathia, dental articulation disorders, and functional defects. Therapy largely depends on the patient's age and the desired esthetic and functional results. This clinical report describes the prosthetic rehabilitation of a 50-year-old woman with hemimandibular hyperplasia. During the diagnostic phase, facial asymmetry was observed, as was the chin midline shifting to the unaffected side and three-dimensional enlargement of one side of the mandible, the condyle, the condylar neck, and the ramus. No biomechanical or functional problems were seen at a five-year follow-up visit, except for physiological wear to the artificial teeth.

Immediate provisional restoration fabrication for immediate implant loading using a modified technique: a clinical report.

This article describes the immediate fabrication and placement of a provisional restoration, using a modified method for impressionmaking. An impression was made before surgery and provisional acrylic temporary restorations with composite resin frameworks were prepared on the solid-screw implant abutments. This article demonstrates this simple method and discusses the benefits of immediate provisionalization after surgery.

Influence of cervical finish line type on the marginal adaptation of zirconia ceramic crowns.

The current study evaluated the effect of different cervical finish line designs on the marginal adaptation of a zirconia ceramic. Four different marginal finish lines (c: chamfer, mc: mini-chamfer, fe: feather-edge and s: rounded shoulder) were prepared on phantom incisors. Die models for each preparation group (N = 28, n = 7 per finish line design group) were made of epoxy resin. Y-TZP (ICE Zirkon) frameworks were manufactured by a copy-milling system (Zirconzahn) using prefabricated blanks and tried on the master models for initial adaptation of the framework; they were then sintered, followed by veneering (Zirconzahn). The finished crowns were cemented with a polycarboxylate cement (Poly F) under 300 g load and ultrasonically cleaned. The specimens were sliced and the marginal gap was measured, considering absolute marginal opening (AMO) and marginal opening (MO) for each coping under a stereomicroscope with image processing software (Lucia). The measurements were statistically analyzed using the Kruskal Wallis, Mann Whitney and Wilcoxon Signed Ranks tests at a significance level of alpha = 0.01. Means of AMO measurement (microm) for the feather-edge finish line (87 +/- 10) was significantly lower than that of the chamfer (144 +/- 14), shoulder (114 +/- 16) and mini-chamfer finish line types (114 +/- 11) (p < 0.01). Means of MO measurements was the lowest for feather-edge finish line (68 +/- 9) (p < 0.01) and then, in ascending order, shoulder (95 +/- 9), mini-chamfer (97 +/- 12) and chamfer (128 +/- 10). The cervical finish line type had an influence on the marginal adaptation of the tested zirconia ceramic. Although the feather-edge finish line resulted in lower AMO and MO values, with its proven mechanical disadvantage, it cannot be recommended in clinical applications of zirconia crowns. This type of finish line has acted solely as a control group to test the null hypothesis in the current study. For better marginal adaptation, both shoulder and mini-chamfer finish line types could be suggested for zirconia crowns.

Comparison of mouth opening angle between dentate and edentulous subjects.

Angle of mouth opening provides information concerning temporomandibular joint mobility. The aim of this study was to compare angle of mouth opening of dentate and edentuluous subjects at similar ages. Eighty (80) subjects, 24 women and 16 men (mean age 51.2 yrs.) for the dentate group and 21 women and 19 men (mean age 52.3 yrs.) for the edentuluous group participated in the study. The angle of mouth opening measurements were performed with a mandibular goniometer at four independent sessions of three measurements. The angle of mouth opening values of the dentate group were significantly higher than that of the edentulous group. The results of this study revealed that tooth loss resulted in a decrease in angle of mouth opening values independent of gender and age. The clinical implications of this finding is that oral function might well be preserved with advancing age if dentition is maintained in good condition.

Effect of antioxidant treatment on bond strength of a luting resin to bleached enamel.

PURPOSE: The aim of this study was to comparatively investigate the effect of antioxidant treatment and delayed bonding after bleaching with carbamide peroxide on the shear bond strength (SBS) of a luting resin to enamel. MATERIALS AND METHODS: Forty flat enamel surfaces were prepared from freshly extracted human molars using a low speed diamond saw, then divided into three bleaching groups (n=10/group) and a control group (n=10). Group 1 consisted of specimens bonded immediately after bleaching. Group 2 specimens were treated with an antioxidant agent, 10% sodium ascorbate, while Group 3 specimens were immersed in artificial saliva for 1 week after bleaching. Specimens in Group 4 were not bleached, but immersed in artificial saliva for 1 week before bonding. Forty ceramic blocks (Empress 2, Ivoclar) were prepared and luted to teeth using a dual-curing resin cement (Variolink II, Ivoclar). The specimens were thermocycled and the SBS tests were performed using a universal testing machine (crosshead speed: 0.5mm/min). Fracture analysis of the bonded surfaces was done using a scanning electron microscope. Statistical analysis was carried out by Kruskall-Wallis and Mann-Whitney U-tests. RESULTS: While the samples that were immediately bonded after bleaching (Group I) demonstrated significantly lower shear bond strengths and 10% sodium ascorbate group (Group II) demonstrated significantly higher bond strengths than control group samples (p<0.05), no significant differences were found among delayed bonded group and control group (p>0.05). CONCLUSION: Using sodium ascorbate with a concentration of 10% may be reliable for reversing the compromised bond strength.

Evaluation of bond strength of various margin ceramics to a zirconia ceramic.

OBJECTIVE: This study evaluated the bond strengths of four different margin ceramics based on fluoroapatite and feldspath to a zirconia ceramic. METHODS: Zirconia cores (Zirconzahn) (N=28, n=7/margin ceramic group) were fabricated according to the manufacturers' instructions (diameter: 4mm; thickness: 2mm) and ultrasonically cleaned. Four different margin ceramics (thickness: 5mm) (Cerabien Zr, Noritake; Ceramco PFZ, Ceramco; e.max, Ivoclar Vivadent and Triceram, Dentaurum) were vibrated and condensed in a stainless steel mould and fired onto their zirconia cores. After trying the specimens in the mould for minor adjustments, they were again ultrasonically cleaned and embedded in PMMA. The specimens were stored in distilled water at 37 degrees C for 1 week and shear bond strength (MPa+/-S.D.) tests were performed in a universal testing machine (crosshead speed: 0.5mm/min). Failure modes were recorded under SEM. RESULTS: Significant effect of margin ceramic types were found on the bond strength values (P<0.05). The mean bond strength values of Ceramco margin ceramic to zirconia was significantly lower (25.4+/-4.5 MPa) (P<0.05) than those of Cerabien (31.6+/-6.4 MPa), e.max (35.9+/-8.4 MPa), and Triceram margin ceramic (38.8+/-7.1 MPa) systems. CONCLUSIONS: Margin ceramics, compatible with zirconia framework material tested in the present study, exhibited high bond strength values. Variations in thermal expansion coefficients might influence their bond strength values.

Comparison of two bond strength testing methodologies for bilayered all-ceramics.

OBJECTIVES: This study compared the shear bond strength (SBS) and microtensile (MTBS) testing methodologies for core and veneering ceramics in four types of all-ceramic systems. METHODS: Four different ceramic veneer/core combinations, three of which were feldspathic and the other a fluor-apatite to their respectively corresponding cores, namely leucite-reinforced ceramic ((IPS)Empress, Ivoclar), low leucite-reinforced ceramic (Finesse, Ceramco), glass-infiltrated alumina (In-Ceram Alumina, Vita) and lithium disilicate ((IPS)Empress 2, Ivoclar) were used for SBS and MTBS tests. Ceramic cores (N=40, n=10/group for SBS test method, N=5 blocks/group for MTBS test method) were fabricated according to the manufacturers' instructions (for SBS: thickness, 3mm; diameter, 5mm and for MTBS: 10 mm x 10 mm x 2 mm) and ultrasonically cleaned. The veneering ceramics (thickness: 2mm) were vibrated and condensed in stainless steel moulds and fired onto the core ceramic materials. After trying the specimens in the mould for minor adjustments, they were again ultrasonically cleaned and embedded in PMMA. The specimens were stored in distilled water at 37 degrees C for 1 week and bond strength tests were performed in universal testing machines (cross-head speed: 1mm/min). The bond strengths (MPa+/-S.D.) and modes of failures were recorded. RESULTS: Significant difference between the two test methods and all-ceramic types were observed (P<0.05) (2-way ANOVA, Tukey's test and Bonferroni). The mean SBS values for veneering ceramic to lithium disilicate was significantly higher (41+/-8 MPa) than those to low leucite (28+/-4 MPa), glass-infiltrated (26+/-4 MPa) and leucite-reinforced (23+/-3 MPa) ceramics, while the mean MTBS for low leucite ceramic was significantly higher (15+/-2 MPa) than those of leucite (12+/-2 MPa), glass-infiltrated (9+/-1 MPa) and lithium disilicate ceramic (9+/-1 MPa) (ANOVA, P<0.05). SIGNIFICANCE: Both the testing methodology and the differences in chemical compositions of the core and veneering ceramics influenced the bond strength between the core and veneering ceramic in bilayered all-ceramic systems.

Lenz microphthalmia syndrome with dental anomalies: a case report.

This report describes the dental management and 7-year follow-up of a 14-year-old boy who showed the typical characteristics of Lenz microphthalmia syndrome, a rare genetic disorder characterized by multiple abnormalities. The main features of the syndrome are microphthalmia, developmental retardation, ear abnormalities, microcephaly, skeletal, digital and urogenital anomalies. The dental anomalies include micrognathia, hypodontia, agenesis of permanent teeth, conic-shaped incisors, and taurodontic molars. The purpose of the report was to document specific oral manifestations and dental anomalies and their management associated with a previously reported case.

The effect of different enamel surface treatments on microleakage of fissure sealants.

OBJECTIVE: The aim of this study was to evaluate the effects of different techniques of surface treatment on the microleakage of fissure sealants in permanent molar teeth in vitro. MATERIALS AND METHODS: 96 extracted impacted human third molars were randomly divided into 8 surface treatment groups (n=12/group) as 1. Er: YAG laser ; (Fidelis II, Fotona, Ljubljana, Slovenia) (125 mj, 20Hz) ; 2. Er: YAG laser + 37% H3PO4 (15s) ; 3. ER: AG laser + 37% H3PO4+Prime&Bond NT ; 4. Er: YAG laser + G Bond ; 5. Er: YAG laser + Prime&Bond NT ; 6. 37% H3PO4 ; 7. 37% H3PO4 + Prime&Bond NT ; 8. G Bond. Sealant material (Clinpro, 3M ESPE, Seefeld, Germany), was applied into the fissures and light-cured for 20s with LED (Bluephase C5, Ivoclar-Vivadent, Schaan, Liechtenstein). Specimens were subjected to thermocycling (1000×, 5-55°C, dwell time: 15s) and immersed in 0.5% basic fuchsin solution for 24h at 37°C. The samples were sectioned and scored on a 3 point rating scale using a light microscope with a magnification of ×20. One-way analysis of variance was used to analyze data. Multiple comparisons were analyzed using Bonferroni test (p=0.05). RESULTS: Er:YAG laser showed the highest microleakage scores whereas Er YAG laser + 37% H3PO4 showed the lowest. Although 37% H3PO4 group showed higher scores than Er:YAG laser + 37% H3PO4, the difference was not statistically significant. CONCLUSION: Etching fissures with phosphoric acid is sufficient prior to fissure sealant application.

Hypohidrotic ectodermal dysplasia: a multidisciplinary approach.

Hypohidrotic ectodermal dysplasia (HED; Christ-Siemens-Touraine syndrome) is a genetic disorder characterized by sparse hair, oligodontia with peg-shaped teeth, reduced sweating, and defects in a number of other ectodermal organs. A partial or complete absence of eccrine glands can lead to recurrent severe overheating that may cause seizures and neurological deficits. This clinical report presents a 14-year-old male patient with hypohidrotic ectodermal dysplasia, including the clinical and radiographic findings, and multidisciplinary treatment. The Schedule for Affective Disorders and Schizophrenia for School Aged Children-Present and Lifetime Version (K-SADS-PL) was administered to patient along with mother to assess for any psychiatric disorders. The screening and rating scales completed by mother and two teachers to evaluate the severity of attention deficit hyperactivity disorder (ADHD) symptoms, and other behavioral problems. Patient's academic performance, adaptive functioning, and problem behavior was evaluated using. The Teacher Report Form. Mental capacity was assessed with the Wechsler Intelligence Scale for Children (WISC-R). Illness Perception Questionnaire Revised was used to systematically assess illness representation attributes and emotional representations of illness. On the psychiatric diagnosis assessment using K-SADS-PL sub-threshold attention deficits and anxiety symptoms were determined. In this case we established a multidisciplinary approach in his treatment with pediatric, dermatological, and dental examinations, beside his psychiatric evaluation. The prosthetic rehabilitation included restoring upper teeth with copings and fabrication of upper and lower complete dentures. Metal framework was not incorporated in the partial denture design allowing modifications as the oral and maxillofacial development continued. Removable complete or partial dentures without metal framework is a treatment of choice until the completion of facial growth at which definitive treatment is considered.

Prosthetic rehabilitation of segmental odontomaxillary dysplasia: seven-year follow-up.

Segmental odontomaxillary dysplasia is an uncommon maxillofacial deformity. Clinically, overgrowth and maturation of the maxillary right or left posterior alveolus and the respective gingiva, lack of premolars, delayed eruption of the adjacent teeth, and malformed primary molars are observed. The purpose of this report was to describe the clinical and radiographic findings of a 47-year-old female with segmental odontomaxillary dysplasia and summarize the prosthetic rehabilitation with fixed and removable partial dentures. A 7-year follow-up did not reveal biomechanical or functional problems except the loss of the mandibular left central incisor and wear of the artificial teeth.