Orientation of the occlusal plane is one of the most important clinical procedures in the prosthodontic rehabili- tation of edentulous patients but definitions of the ala-tragus line (ATL) causes confusion, because the exact points of reference for this line are not clear.

The aim of this study was to corroborate a correlation between Camper's plane and natural occlusal plane in normal dentulous subjects and to ascertain the most relevant posterior reference point for establishing Camper's plane.

In this study, 40 subjects with com- plete natural dentition and Angel's Class I occlusal relationship were selected. The subjects were photographed in sitting erect posture with head unsupported while clenching on a fox plane. The angles between the following lines were measured using digital screen protractor, the occlusal plane and Ala to superior border of tragus, the occlusal plane and Ala to middle border of tragus, as well as occlusal plane and Ala to inferior border of tragus. Descriptive statistics, one sample t-test and, independent t-test were done to analyze the data.

There was no parallelism between the occlusal plane and ATL with three different posterior ends and one sample t-test showed that the angles between them were significantly different from zero (p < 0.001). However, the inferior border of the ATL had the lowest mean angle, 1.99° (4.32) and was almost parallel to the occlusal plane.

Ala-tragus line from Ala of the nose to the inferior border of tragus as a posterior reference point can be considered as a reliable occlusal plane for complete denture fabrication.

Rathod N, Sood P, Pasam N. Analysis and Comparison of Correlation between Camper's Plane and Natural Occlusal Plane in Normal Dentulous Subjects. Int J Prosthodont Restor Dent 2017;7(3):81-85.

To evaluate surface hardness and dimensional accuracy of type IV dental stone after incorporation of disinfectants.

A total of 100 specimens, 50 (40 mm⨯ 10 mm) disk shaped and 50 frustum cone shaped, were fab- ricated from type IV dental stone after incorporation of various disinfectants, namely glutaraldehyde (2%), iodophor (1.76%), chlorhexidine (2%), and sodium hypochlorite (1%), for evaluation of surface hardness and dimensional accuracy. Surface hardness was tested after 1- and 24-hour time interval using Rockwell hard- ness testing machine. Dimensional accuracy was measured using traveling microscope. Data obtained were compiled and analyzed statistically by using analysis of variance and post hoc test.

Results showed significant decrease in surface hard- ness of samples incorporated with disinfectants at 1 hour as compared with control (distilled water). Surface hardness of all the samples increased with time and was almost equal to control group at 24-hour interval, with iodophor showing the maximum value in comparison with the other disinfectants used. When dimensional accuracy of all the groups was compared, iodophor and sodium hypochlorite were found to cause negative alterations.

Within the limitations of this in vitro study, it was concluded that incorporation of disinfectants in die stone during mixing did not affect the hardness value at 24-hour interval. Dimensional accuracy was altered by iodophor and sodium hypochlorite, but remained unaffected by chlorhexidine and glutaraldehyde.

Bakshi A, Dang R. Effect of Incorpo- ration of Disinfectants on Surface Hardness and Dimensional Accuracy of Die Stone An in vitro Study. Int J Prosthodont Restor Dent 2017;7(3):86-91.

A technique to reproduce the exact natural anatomy of the palatal surface, known as “anatomical contour” in even thickness onto the maxillary permanent denture base.

In constructing oral prostheses, dentists are pri- marily concerned with replacing structural losses. However, we are necessarily adding to regions having no structural loss, e.g., the hard palate region. When these structures are covered by a denture, the proprioceptive feedback mechanism is changed and, naturally, dentures affect phonetics, which causes a tem- porary change in the articulation of speech sounds.

A metal ring plate in standardized different thick- nesses (1.5, 2, and 2.5 mm), which adapt to dental flask lower base, is made and used in the routine fabrication method of denture base processing.

The quick and easy methods of replicated entire individualized natural anatomical palatal contour, in various even thicknesses in the permanent maxillary denture base, including the incisive papilla, palatine suture, and palatal rugae, can be employed to newly fabricate maxillary complete dentures.

This is a comprehensive approach to utilize the collective factors of suggested methods, techniques, and conclusion by various authors for speech improvement with maxillary denture.

Sekar CG, Sabarigrinathan C, Vinayagavel K, Ramkumar K, Dhanraj M. Novel Technique for Replication of Natural Palatal Anatomy onto the Maxillary Permanent Denture Base within an Even Thickness. Int J Prosthodont Restor Dent 2017;7(3):92-96.

The aim of this study is to compare the various cold sterilization techniques for sterilizing dental burs and diamond points by assessing the microbial growth in culture media on them before and after sterilization.

The following four disinfectants were used: 2% glutaraldehyde, 5.2% sodium hypochlorite, hydrogen peroxide, and 70% ethanol. There were two main groups taken as group I-carbide burs and group II-diamond burs. A total of 48 samples were collected, 12 samples per disinfectant. Each sample has two burs collected from same patient. One acts as control group which means only microbial count was deter- mined without disinfection. The other one would be determined as microbial count before and after disinfection. The microbial assessment was done using brain heart infusion (BHI) broth and counted by plating in chocolate blood agar and MacConkey agar.

The obtained results were statistically analyzed by one-way analysis of variance (ANOVA) test and post hoc test. The results revealed that there was statistically significant difference between sodium hypochlorite and surgical spirit, sodium hypochlo- rite and hydrogen peroxide. There was no statistically significant difference between sodium hypochlorite and glutaraldehyde.

The results of this study revealed that sodium hypochlorite and glutaraldehyde are most effective than hydro- gen peroxide, and surgical spirit is the least effective disinfectant. However, there was clinical significance in level of disinfection of all four disinfectants.

Ranganathan S, Manvi S, Gopalakrishna S, Renukanath CK. Comparison of Various Cold Sterilization Tech- niques on Routinely used Carbide Burs and Diamond Points. Int J Prosthodont Restor Dent 2017;7(3):97-102.

Pawar RS, Kulkarni RS, Pimpale SK. Clinical Considerations while increasing Occlusal Vertical Dimension. Int J Prosthodont Restor Dent 2017;7(3):103-107.