Effects of tongue movements on lingual sulcus depth while border molding in mandibular complete dentures.

Background: In general, people speak and swallow frequently in their daily lives rather than making exaggerated tongue movements. Aim: The aim was to compare the effect of tongue movements on lingual sulcus depth, during the border molding process of impression making of mandibular complete dentures. Settings and Design: In total, 32 double master impressions were made. One of these pairs was obtained by allowing the patient to swallow and the other by enabling the tongue to make excessive movements. Materials and Methods: Measurements were taken from different regions of the lingual sulcus by determining the length of the parallel lines drawn from fixed points marked on the residual ridge crest to the deepest point of the alveolingual sulcus. These measurements were performed using a RMI three‑dimensional measurement system. Statistical Analysis Used: Data were compared using the paired t‑test (alpha = 0.05). Results and Conclusion: The high value found in casts with border molding, while swallowing was statistically significant in vertical and horizontal directions of the anterior lingual sulcus region (<0.001), vertical direction of the middle lingual sulcus region (MLSR) (<0.05) and horizontal direction of the retromylohyoid and MLSR (<0.05). According to the paired t‑test, the mean differences between the 32 casts were statistically significant (<0.001). Within the limitations of this study, the swallowing in the vertical and horizontal directions provided higher values compared to the excessive movement of the tongue.

Tensile bond strength of composite luting cements to metal alloys after various surface treatments.

Aims: To evaluate the effects of two different surface treatments and bonding agents on tensile bond strength between a Co-Cr and a Ni-Cr cast alloy and two resin-luting cements. Materials and Methods: Two hundred and forty alloy samples were cast and subjected to surface treatments such as sandblasting, chemical etching, and sandblasting plus chemical etching. Panavia F and CandB cement were used as cementing mediums. The etching qualities were examined by a stereooptic microscope. Failure surfaces were examined throughout scanning electron microscopy. The data were evaluated using statistical methods, namely analysis of variance and multiple comparison test (Tukey HSD). Results: Significant differences were found in the bonding provided by the various cements (P < 0.001) and also type of surface treatments (P < 0.001). For all groups, sandblasted surfaces showed the highest bond strength values. There was no significant difference between the Cr-Co and the Cr-Ni alloys (P > 0.05). Conclusions: Panavia F showed higher tensile strength and the sandblasted samples possessed higher tensile strength.