The objective of the present study was to determine the color changes resulting from the aging process in two cold and three hot curing soft liners and two hard liners. Seven samples were fabricated for each material. The initial color measurements were made with a UV-Visible Recording Spectrophotometer. The samples were then placed in an accelerated aging chamber to simulate the aging process. The color of the samples was then measured again with a colorimeter, and the color changes (AE) were calculated. The critical mark of color change (AE) has been quantified by the NBS. It was concluded that cold curing soft liners were not color-stable, and that hot curing soft liners and hard liners had similar color durability. These results suggest that colorants used in cold curing soft liners must be reinforced.

View full abstract

A study was conducted to determine whether cryotherapy of bone exposed during the surgical removal of wisdom teeth is able to reduce the intensity of pain and general discomfort. Study design. A prospective investigation of 107 patients who required extraction of two wisdom teeth, one on the left and one on the right side of the lower jaw. Cryotherapy was carried out on one side only. Employing a visual analogue scale, the intensity of pain and general discomfort (swelling, inflammation, insomnia etc.) was recorded. Other parameters such as swelling, patient preference, and duration of the operation were also recorded. The chi-squared test was employed to compare the results between the treated and non-treated sides. There was significantly less pain, swelling and discomfort following the use of cryotherapy. Patient preference was also for cryotherapy. Operation time and the occurrence of inflammation were similar in both groups. In conclusion, cryotherapy is an effective procedure for reducing pain, swelling and general discomfort following extraction of a wisdom tooth in the lower jaw without creating irreversible sequelae.

View full abstract

The purpose of this study was to evaluate the inhibitory effect of funoran containing chewing gum (FG) and eucalyptus extract-containing chewing gum (EG) on plaque formation. Fifteen dentists or dental students were assigned a random order of use of either FG, EG or a control gum. All subjects received professional tooth cleanings before the experiment. During the four-day test periods, no oral hygiene measures were allowed other than chewing three pieces of gum for approximately 10 min daily. Chewing gum was used following each morning, noon and evening meal. Plaque formation was evaluated by the Quigley and Hein index. The FG (1.83±1.1) and EG (1.97±1.1) significantly reduced plaque compared to the control gum (2.57±1.2). Our results suggest that FG and EG may be useful in inhibiting dental plaque formation.

View full abstract

A case of squamous odontogenic tumor (SOT) of the maxilla related to an embedded tooth in a 42-year-old Japanese woman is described. The patient felt a slight pain of her left maxilla 2 months before visiting our dental hospital. Histologically, the tumor consisted of a proliferation of round and elongated epithelial islands of well-differentiated squamous epithelium separated by a fibrous stroma. The epithelial nests varied in size, and were composed of cuboidal or squamous cells of basal layer and matured intermediate cells with prominent intercellular bridges. Although no calcified materials were found, microcystic degeneration was occasionally observed in the epithelial islands. These findings indicated that this tumor is a SOT of the maxilla.

View full abstract

A case is reported of a 21-year-old Japanese man examined for unerupted molar teeth on the left side of both jaws. Intraoral examination revealed edentulous regions from the second premolar to the molar, with moderate atrophy of the upper alveolar ridge. A panoramic X-ray revealed eight impacted teeth. The impacted mandibular teeth were extracted through decortication and bone replacement. The impacted maxillary teeth were extracted following reflection of a mucoperiosteal flap. The large defects caused by the extractions in both jaws were filled with autogenous cancellous marrow and bone chips. Eleven months later, in the first stage of the Branemark implant procedure, fixtures were placed in the edentulous regions of both jaws, with simultaneous additional corticocancellous block onlay bone grafting in the maxilla to correct slight resorption. After another seven months, second-stage abutment surgery was performed. Occlusion was then restored through a prosthetic procedure. Next, orthodontic treatment was commenced, using the implant supported teeth as an anchor. Despite the slight resorption in the maxilla, implantation was successful and occlusion was restored in the previously edentulous regions. This suggests that application of a simultaneous corticocancellous block onlay bone graft is a valuable basis for implant procedures in the maxilla.

View full abstract