PURPOSE The purpose of this in vitro study was to determine the effects of six surface treatment methods on the surface roughness of two feldspathic ceramic materials. MATERIALS AND METHODS One hundred twenty metal discs were cast (Remanium CS). A low-fusing feldspathic ceramic (Vita Omega 900) was fired onto 60 metal discs, and an ultra low-fusing feldspathic ceramic (Finesse) was fired onto the other 60 metal discs. Six surface treatment methods were selected: (1) autoglazing (AUG), (2) overglazing (OVG), (3) polishing (POL), (4) fine diamond disc grinding + polishing + autoglazing (FDPA), (5) coarse diamond disc grinding + polishing + autoglazing (CDPA), (6) polishing + autoglazing (PA). Omega specimens were assigned to six experimental groups representing six surface treatment methods (Om-AUG, Om-OVG, Om-POL, Om-FDPA, Om-CDPA, Om-PA) (n = 10). Finesse specimens were also assigned to six experimental groups (Fn-AUG, Fn-OVG, Fn-POL, Fn-FDPA, Fn-CDPA, Fn-PA) (n = 10). Treated ceramic surfaces were examined by means of profilometry and transmission electron microscopy. RESULTS In Omega groups mean roughness values ranged as follows: group Om-AUG = Om-POL > Om-OVG > Om-CDPA = Om-FDPA > Om-PA (p < 0.001). No significant difference was found between groups Om-AUG/Om-POL and Om-CDPA/Om-FDPA (p > 0.05). In Finesse groups mean roughness values ranged as follows: Fn-CDPA > Fn-FDPA = Fn-AUG = Fn-POL = Fn-OVG > Fn-PA (p < 0.001). No significant difference was found between Fn-FDPA, Fn-AUG, Fn- POL and Fn-OVG (p > 0.05). CONCLUSIONS For both ceramic types, the smoothest surfaces were obtained with polishing prior to autoglazing. Diamond disc grinding prior to polishing and autoglazing (Fn-FDPA, Fn-CDPA) displayed the roughest surfaces in ultra low-fusing ceramic (Finesse). Autoglazing alone and polishing displayed the roughest surfaces in low-fusing ceramic material (Om-AUG, Om-POL).

Summary The increased desire of patients to maintain their dentition has forced conservative dentistry to conserve the teeth in the mouth which are planned to be removed. In the light of this finding it is known that periodontally compromised teeth with severe bone loss at furcation area may well be retained of their roots. In this case report bicuspidization of the right first mandibular molar with a simple procedure and subsequent prosthetic treatments are presented.

Patients with complete facial nerve palsy are at risk of severe eye complications due to corneal exposure. Gold weight implantation improves function, cosmetic appearance and morbidity. Three patients with nerve palsy underwent insertion of precisely prepared gold weights between May 2000 and December 2001. Individual gold weights were implanted into a small pocket between the orbicularis oculi and the tarsal plate of the upper eyelid, fitting the curvature of the eye. According to follow-up examinations (after at least 5 years), none of the gold weights had extruded; all patients experienced marked improvement of their dry-eye symptoms and expressed a high degree of satisfaction. Implantation of gold weights is effective and should be considered in all patients for the management of paralytic lagophthalmos.

OBJECTIVES:The purpose of this study was to evaluate compressive and tensile stress values and patterns on implant-supported all-ceramic restorations applied in maxillary partially edentulous cases by utilizing the 3-dimensional (3-D) finite element stress analysis.METHOD AND MATERIALS:Two different 3-D finite element designs representing a maxillary implant-supported fixed partial denture (from maxillary canine to second premolar) were constructed with 3 different core materials (Inceram-Zirconia, IPS 2 disilicate glass-ceramic, cobalt-chromium). In the first design, the cross-sectional connector areas of the dentures were constructed to be 3.5 3 3.5 mm. In the second design, the cross-sectional areas were decreased to 2 3 2 mm. A load of 550 N was applied in oblique direction onto the pontic.RESULTS:The compressive and tensile stress levels obtained in the second design were higher than the first one for all materials. The compressive and tensile stresses were higher when the loads were directly applied onto the cores and the framework than when they were applied onto the porcelain sets. The cross-sectional connector area between the abutment and the pontic component has a great effect on the success of all-ceramic implant-supported fixed partial dentures.CONCLUSIONS:All 3 materials seem to have sufficient characteristic strength for 3-unit posterior implant-supported fixed partial dentures. Only the tensile stress value obtained for IPS 2 disilicate glass core material in the second design was higher than the material's characteristic strength value when the load was applied directly onto the core.

Objective: Hypoparathyroidism is an endo crine based metabolic disorder and characterized by low serum levels of parathormo ne and hypocalcaemia. However, pseudohypoparathyroidism is cha ra terized by high serum levels of parathormone and hypocalcae mia. In this study, we report a 20-year-old Turkish male with ps eudohypoparathyroidism and discuss his clinical, radio graphic and laboratory test characteristics together with his oral manifes tations. We also discuss the prosthetic management of treatment. Case Report: Clinical examination showed that the patient with pseudohypopara thyroidism had a short stature, round face, low nasal bridge, short neck, z deformity on hands and feet deformity and weakness. Biochemical tests showed hypocalc aemia (8. 1 mg/dL) and high serum levels of parathormone (344 pg/ml). Bone mineral density (BMD) studies revealed clear o ste penia (BMD: 0.757) from L1L4 region, and clear osteoporosis (BMD: 0.507) from total BMD results. The oral examinations showed limited mouth opening a d the maxilla was quite small as compared with the mandible . The dental radiographic evaluations showed pseudoanadon ti , malformed dental roots and lack of periodontal spac es. In addition, there were a lot of unerupted teeth in both j aws, except lower left central incisor. We also determined several internal resorptions in unerupted teeth. There were large pu lp chambers located primarily in lower molar teeth. Conclusion: We believe that, for better prosthetic rehabilitat on of the patient, orthodontic treatment of unerupted teeth was quite impossible due to lack of enough space. Advanced de ntal surgery techniques were refused by the patient. We refrained from extraction of unerupted teeth to preserve alv eolar ridge levels of the patient. Finally, the patient’s mas ticatory and speech functions and aesthetics were restored with conventional complete dentures.

Objetivo: La exposicion del surco gingival y el control de la hemorragia son prerrequisitos imprescindibles para el tratamiento de las lesiones cervicales y la mejora de la calidad de las impresiones antes de la fabricacion de restauraciones indirectas. Para este proposito se emplean con mucha frecuencia hilos retractores impregnados en diferentes medicamentos. Sin embargo, no se conocen bien los efectos que estos agentes quimicos pueden ejercer a largo plazo sobre los tejidos gingivales. El proposito de este estudio fue comparar los efectos histopatologicos sobre el tejido gingival de 2 soluciones diferentes ampleadas para su retraccion. Metodo y materiales: En este estudio in vivo llevado a cabo sobre perros, se emplearon como medicacion para la retraccion una solucion de cloruro de aluminio al 10% y una solucion de sulfato ferrico al 15, 5%. Los hilos impregnados se dejaron en el surco gingival de los perros durante 3 minutos. Despues de retirar los hilos se tomaron biopsias gingivales a los 30 minutos, 24 horas, 7 dias, y 12 dias. En todos los especimenes, la evaluacion histologica se realizo mediante el microscopio optico, evaluando el grado de perdida epitelial, la alteracion del tejido conectivo, y la inflamacion. Resultados: El examen histopatologico del tejido gingival revelo que la solucion de sulfato ferrico produjo al inicio importantes cambios en los tejidos gingivales. Sin embargo, al termino del dia 12 el tejido retorno a su aspecto histologico normal. Conclusion: Los resultados de este estudio revelaron que los efectos biologicos de la solucion de sulfato ferrico son mas satisfactorios que los de la solucion de cloruro de aluminio. No obstante, ambos medicamentos son fiables y pueden usarse en la retraccion gingival.

Acrylic resin dentures may have cytotoxic effects on oral soft tissues. However, there is sparse data about the cytotoxic effect of fibre-reinforced acrylic resin denture base materials. The purpose of this in vitro study was to determine the effect of two fibre impregnation methods on the cytotoxicity of a glass and carbon fibre-reinforced heat-polymerized acrylic resin denture base material on oral epithelial cells and fibroblasts. One hundred acrylic resin discs were assigned to five experimental groups (n = 20). One of the groups did not include any fibre. Two groups consisted of silane and monomer treated glass fibres (Vetrolex) impregnated into acrylic resin (QC-20) discs. The other two groups consisted of silane and monomer treated carbon fibres (Type Tenox J, HTA). Untreated cell culture was used as positive control. The human oral epithelial cell line and buccal fibroblast cultures were exposed to test specimens. The cytotoxicity of the test materials was determined by succinic dehydrogenase activity (MTT method) after 24 and 72 h exposures. Data were analysed with a statistical software program (SPSSFW, 9.0). A one-way analysis of variance (ANOVA) test and Bonferroni test were used for the comparisons between the groups. All statistical tests were performed at the 0.95 confidence level (P < 0.05). After 24 and 72 h incubation, cell viability percentages of all experimental groups showed significant decrease according to the positive control cell culture. Fibroblastic cell viability percentages of silane and monomer treated fibre-reinforced groups were lower than the unreinforced group. Cell viability of monomer-treated groups displayed the lowest percentages. Elapsed incubation time decreased epithelial cell viability in silane-treated groups. Fibroblastic cell viability was not influenced by elapsed time except the unreinforced group.

Objective: Exposure of the gingival sulcus and control of hemorrhage are prerequisites to the treatment of cervical lesions and improving the quality of impressions prior to fabricating indirect restorations. Gingival retraction cords saturated with different medicaments are widely used for this purpose. However, the long-term effects of the chemicals in gingival tissues are not clear. The purpose of this study was to compare the histopathologic effects of 2 different retraction solutions in gingival tissue. Methods and materials: In this in vivo study, a solution of 10% aluminum chloride and a solution of 15.5% ferric sulfate were used as retraction medicament in dogs. The saturated cords were allowed to remain in the gingival sulcus of the dogs for 3 minutes. After the removal of the cords, gingival biopsies were taken at 30 minutes, 24 hours, 7 days, and 12 days. For all specimens, histologic evaluation was performed by light microscopy to determine the degree of epithelial loss, alteration of the connective tissue, and inflammation. Results: Histopathologic examination of gingival tissue revealed that the ferric sulfate solution caused significant changes in gingival tissues at the beginning. However, the tissue returned to its normal histologic appearance at the end of day 12. Conclusion: The results of this study revealed that the biologic effects of ferric sulfate solution are more satisfactory than aluminum chloride solution. However, both medicaments are reliable and can be used in gingival retraction.

PURPOSE:The purpose of this in vitro study was to demonstrate the dentinal tubule-occluding effect of desensitizing laser treatment on dentin surfaces using environmental scanning electron microscopy (E-SEM).MATERIALS AND METHODS:Ground dentin surfaces were divided into 5 areas. Each area received a different mode of laser irradiation (low potency [LP] versus high potency [HP] and short time [ST] versus long time [LT]). Lased dentin surfaces were viewed and graded under E-SEM at x5000 magnification.RESULTS:The tubule closure rates of 4 different irradiation modes were as follows: LP/LT (74%) > HP/ST (70%) > LP/ST (51%) > HP/LT (46%) > control (6%).CONCLUSION:It was demonstrated that desensitizing laser application was an efficient treatment option for the occlusion of dentinal tubule apertures.

Little information is available on the immunological basis for side-effects of dental materials. The objective of this study is to evaluate effects of pure metals, dental alloys and ceramic on cell viability and interleukin-1 beta (IL-1 beta) release in three-dimensional human gingival fibroblast cultures as an indicator of their biological performance in gingival tissues. The gingival fibroblast cultures were exposed to test specimens fabricated from nickel, iron, molybdenum, copper, indium, gold, Ni-Cr-Mo alloy (Remanium CS), Au-Pt-In alloy (Pontostar) and a dental ceramic (In-ceram). Cell viability was determined by the MTT method 24 and 48 h after exposure. Assays for IL-1 beta were carried out by ELISA. Statistical analysis was performed applying the non-parametric Mann-Whitney pairwise test. Dental ceramic and gold did not influence cell viability after 24 and 48 h. Cell viability was determined after 24 and 48 h to nickel (79-77%), iron (92-90%), molybdenum (86-83%), copper (48-36%), indium (90-90%), Remanium CS (83-80%), Pontostar (94-91%) compared with control cultures. Dental ceramic, Pontostar and gold had no significant influence on IL-1 beta secretion. The highest amounts of IL-1 beta (10-fold) levels were determined in cell cultures exposed to copper. Indium, molybdenum and iron induced twofold IL-1 beta levels compared with untreated control cultures. These results support that some metals may alter immune responses and thereby contribute to a variety of dental pathological conditions and three-dimensional cell culture models for gingival fibroblasts appear to be suitable for in vitro studies.

The purpose of this study was to determine the influence of various types of dental casting alloys and ceramic upon cell viability and the synthesis of IL-1beta (b) in a three-dimensional cell culture system consisting of human gingival fibroblast, and to determine their effect in gingival inflammation. Au-Pt-In alloy (Pontostar), Ni-Cr-Mo alloy (Remanium-CS), a titanium alloy (Ti-6Al-4V), copper (Cu), and an all ceramic (In-Ceram) were used as test materials. The materials were exposed to a three dimensional cell culture in order to determine their effect on cell viability and IL-1 (b) secretion level. Cell viability was measured by MTT test after exposure for 24h and 48h. For IL-1 (b) measurement, assay aliquots were taken from exposed media after 1h, 3h, 7h, 24h and 48h. Assays for IL-1 (b) were carried out by ELISA. In-Ceram, Pontostar and Ti-6Al-4V alloy did not influence cell viability. Copper (52-64%), and Remanium CS (17-20%) were found to be cytotoxic, compared to control cultures. In-Ceram, Pontostar and Ti-6Al-4V had no significant influence on IL-1 (b) secretion. Remanium-CS increased IL-1(b) levels two fold compared to untreated control cultures. Our findings suggested that Ti-6Al-4V, In-Ceram and Pontostar did not cause elevated IL-1 (b) release from cells at non-toxic levels. On the other hand, Remanium-CS showed moderate toxicity and caused increase in IL-1 (b) levels.

The objectives of this study were to detect the cytocompatibility of five different types of denture base resins and to compare the cytotoxic effect of these materials on primary human gingival fibroblasts. The gingival fibroblast cultures were exposed to test specimens from light-cured resin, heat-cured resin, self-cured resin, microwave-cured resin and injection-cured resin. Cell viability was determined by the 3-(4,5-dimethylthiazoyl)- 2,5-diphenyl-SH-tetrazolium bromide (MTT) method at the 48th and 120th hours after exposure. All of the test specimens were cytotoxic to primary gingival fibroblast cultures. Self-cured resin was the most toxic denture base material among the other test materials. The cytotoxicity decreased in the order of heat-cured, visible light-cured, injection- cured, and microwave-cured resin. It is concluded that different denture base materials displayed low to intermediate degrees of cytotoxicy depending on their chemical composition and polymerization type. In the case of long term use, denture bases with low cytotoxicity should be preferred.

Objective. The aim of the study was to examine the dose enhancement from scattered radiation at bone-dental implant interfaces during simulated head and neck radiotherapy.Study design. Four cylindrical titanium dental implants with 3 different sizes and lengths were implanted into a human mandible in 4 different positions. Ionization measurements for 6 MV X, 25 MV X, and Co-60 gamma rays were done. Thermoluminescent dosimeter (TLD100) chips were used to measure radiation dose enhancement due to the scattered electrons from titanium and electronic disequilibrium at the tissue-metal interface.Results. The results showed that for Co-60, there is a 21% maximum increase in dose to alveolar mandibular bone at the close proximity to the titanium. For 6-MV x-rays the dose enhancement increase was almost the same or slightly lower than for Co-60, while for 25-MV high-energy x-rays, dose enhancement was lower than that of others. This increase in dose enhancement fell off rapidly and became insignificant at 2 mm from the interface.Conclusion. Total dose that may lead to osteoradionecrosis risk of the mandible is slightly but not significantly affected by the scattered dose of the dental implants of lower jaw in the radiation field exposed to 3 different radiation beams.

Although bone healing around titanium implants has already been evaluated, the effect of pulsed electromagnetic fields (PEMF) during the period of bone maturation around titanium dental implants has not yet been investigated. The aim of this study was to evaluate the effects of PEMFs on bone formation following the insertion of titanium-dental implants in the rabbit mandibular model. Ti-6Al-4V (Sulzer Calcitek, California, USA) dental implants were inserted into the mandibulae of 28 New Zealand rabbits (6 weeks old). Fourteen were stimulated with PEMFs for 2 consecutive weeks, 4 h/day, at a magnetic intensity of 0.2 milli Tesla (mT), while the other 4 animals were not treated (control group). The rabbits were sacrificed at 2 and 8 weeks (after 6 weeks of non-stimulation) for histopathologic analysis around the implants. No significant difference in bone osteoblastic activity, new trabecular bone and fibrous tissue formation were observed between the control and the PEMF treated groups. However, significant differences in bone osteoblastic activity and new trabecular bone formation were observed between the control group and the PEMF treated group at week 8 (p

In this study, a pulsed electromagnetic field generator system, to be developed for testing on rabbits, is presented. It is aimed to observe the success of therapy (to be used in electromagnetic fields) after dental implant operations. A pulsed electromagnetic field generator system includes timing/control circuit for controlling frequency and duration of pulse, coil interface circuits for triggering coil and coil component. In this system, it is possible to adjust the frequency and the duration of pulses for various applications. The frequency and the duration of pulses used in tests are 100Hz and 25µsn respectively with 14 rabbits. 7 rabbits (first group) are settled with implant materials, and then progressing of bone formation after dental implant operations is observed at a magnetic intensity of 0.2mT, the other group are settled with implant material and waited normal healing period. It may be useful for osseointegration. But there is need for practical usega in dentistry.