Disinfection of polyvinyl siloxane impression material by gaseous ozone.

STATEMENT OF PROBLEM: Impression materials must be disinfected to avoid cross-contamination before they are sent to the dental laboratory. However, whether aqueous state disinfectants affect material wettability is unclear. PURPOSE: The purpose of this in vitro study was to compare the efficacy of gaseous ozone and sodium hypochlorite (NaOCl) in disinfecting light-body consistency hydrophilized polyvinyl siloxane (PVS) impression specimens inoculated with a cocktail of Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Enterococcus faecalis. The effect of both disinfectants on the wettability of the material was also evaluated on uninoculated specimens. MATERIAL AND METHODS: Disk-shaped specimens (N=140) were subjected to the either gaseous ozone or NaOCl for up to 30 minutes at room temperature. In the ozone group, the specimens were ozonated under a continuous stream of gaseous ozone at a concentration of 12.8 mg/L, while the specimens in the NaOCl group were immersed into 0.5% NaOCl solution. Reductions in the size of the bacterial population at the end of the exposure times were determined by the plate count technique. The contact angle measurements on the impression surface were used to determine the wettability of the specimens. Results were analyzed with 1-way ANOVA followed by the Tukey post hoc test (α=.05). RESULTS: The material exposed to both disinfectants for 30 minutes demonstrated a reduction in the number of bacteria of up to more than 3 log. The contact angle of water on the material increased significantly (P<.001) after only 5 minutes of contact with the NaOCl solution. However, the treatment with gaseous ozone for 30 minutes resulted in a reduced contact angle (P<.001). CONCLUSIONS: Gaseous ozone treatment was identified as a promising method of disinfecting polymerized PVS impression materials because of its positive effect on the wettability of the material.

The Effects of Laser with Different Parameters and Crosshatching on Fibroblast Adhesion and Proliferation to Implant Surfaces.

PURPOSE: To compare the adhesion and proliferation effect of HGF-1 cells on pure titanium disks when the surfaces are unprocessed (machined surfaces after slicing) or modified with a laser. MATERIALS AND METHODS: Twenty-eight titanium disks were divided into four groups. Three surface topographies were created using an erbium fiber laser: group 1 (unidirectional application [no crosshatch]), group 2 (crosshatching in two directions), and group 3 (crosshatching in three directions). The samples in group 4 were unprocessed and served as controls. The surface roughness of samples was investigated with scanning electron microscopy (SEM) and measured with a mechanical surface profilometer. HGF-1 cell line was used to analyze the adhesion of fibroblasts on the sample surfaces. The authors used SEM, XTT, and acridine orange tests to determine the adhesion of HGF-1 onto specimen surfaces and the cell morphology after incubation for 72 hours. XTT results and surface roughness values for all specimens were analyzed using the Kruskal-Wallis test. RESULTS: Ra values of group 1 to group 4 (control) were 1.13, 0.26, 0.38, and 0.19, respectively. Crosshatching decreased the surface roughness values compared with unidirectional application (P = .003). Cell morphology observed in SEM showed that the elongation direction of cells resulted in all directions related with additional filopodia extentions within the crosshatch groups. Therefore, the highest cell viability was also detected in the three-directional crosshatch group (group 3) (P = .000) in XTT assay. According to the acridine orange test, higher cell numbers were seen in group 3, similar to the XTT findings (P = .86). CONCLUSION: Crosshatching significantly increased the cell-covered implant surfaces compared with the unidirectional group. Decreasing the surface Ra values via crosshatching helped spread the fibroblast over the implants in any direction, thus increasing cell proliferation and adhesion.

Majewski osteodysplastic primordial dwarfism type II: clinical findings and dental management of a child patient.

Majewski osteodysplastic primordial dwarfism type II (MOPD II) is an unusual autosomal recessive inherited form of primordial dwarfism, which is characterized by a small head diameter at birth, but which also progresses to severe microcephaly, progressive bony dysplasia, and characteristic facies and personality. This report presents a case of a five-year-old girl with MOPD II syndrome. The patient was referred to our clinic with the complaint of severe tooth pain at the left mandibular primary molar teeth. Clinical examination revealed that most of the primary teeth had been decayed and all primary teeth were hypoplastic. Patient's history revealed delayed development in the primary dentition and radiographic examination showed rootless primary molar teeth and short-rooted incisors. The treatment was not possible due to the lack of root of the left mandibular primary molars; so the teeth were extracted. Thorough and timely dental evaluation is crucial for the prevention of dental problems and the maintenance of oral health in patients with MOPD II syndrome is of utmost importance.