Acrylic processing of waxed-up dentures is considered to be a crucial and technique-sensitive procedure. Even after investing a lot of time and clinical skill a definitive movement of teeth during and after processing has long been observed which lead to occlusal discrepancies and disturb the harmonious occlusal scheme achieved earlier. Shifting of the teeth can occur as a result of the investing procedures and investing materials. The objective of this study was to evaluate and compare the movement of artificial teeth in two-dimensions of space (anteroposterior and mediolateral) during processing of the waxed-up dentures using two different gypsum materials for investing.

Two groups of 15 waxed-up maxillary dentures were processed using two different investing mediums (a) dental plaster and (b) combination of dental stone core and plaster mold. The artificial teeth movement was measured in the mediolateral and the anteroposterior directions between predetermined reference points before and after processing with the aid of a traveling microscope. The findings were statistically analyzed using parametric t-tests and ANOVA F-test.

Artificial teeth movement in both the anteroposterior and mediolateral direction was less with the use of investment combination of dental stone core and plaster mold when compared to the conventional method of investing with dental plaster.

The dental stone core method is superior in view of the fact that it produces significantly less artificial teeth movement than the conventional method. However, neither of the investing methods is successful in completely preventing artificial teeth movement.

Acetal resin has been introduced as an esthetic partial denture clasp material. However, the effects of these clasps on the abutment teeth supporting structures were not clear.

To evaluate the effects of acetal resin clasps on the abutment teeth supporting structures as compared to cobalt-chromium clasps.

Twenty patients, 12 males and 8 females, with Kennedy class III modification I partially edentulous maxilla and dentulous mandibles were selected for this study. Patients were divided into two equal groups; group 1 received maxillary cobalt-chromium partial denture frameworks with acetal resin Akers clasps. Group 2 received maxillary partial denture with cobalt-chromium frameworks and Akers cobalt-chromium clasps. Crevicular fluid, epithelial attachment loss, and bone height and density of the abutment teeth were evaluated at partial denture insertion and after 6 and 12 months. Paired t-test was used at p ≤ 0.05 to assess the changes in the above parameters in each group. Student t-test was used to compare between the two groups.

Crevicular fluid measurements were significantly higher in the first group than that in the second group. There were no differences in epithelial attachment loss between the two groups. There were significantly higher reductions in the bone height and in the bone density in the second group than that in the first group.

Acetal resin clasps were superior to cobalt-chromium clasps as produced fewer reductions in bone height and in bone density around the abutment teeth inspite of produced increase in the crevicular fluid.

Since there were lesser reductions in bone height and in bone density around acetal resin clasp abutments, it could be used successfully to retain partial dentures. However, meticulous oral hygiene and proper insertion and removal of partial denture with acetal resin clasps were required to decrease gingival inflammation and crevicular fluid amount.

Simulation of jaw movements in an articulator requires one of the important condylar parameters, i.e. horizontal condylar inclination (HCI) to be registered in the patient and transferred to a mechanical device (articulator). The most popular and commonly used technique to determine horizontal condylar inclination (HCI) is by use of interocclusal records. Clinical studies comparing the effects of different interocclusal recording materials on reproducibility of protrusive settings in semiadjustable articulators have not been studied much. Hence, the present clinical study was conducted to comparatively assess the effects of three commonly used interocclusal recording materials; namely wax, polyvinylsiloxane, polyether in obtaining HCI values in two commonly used semiadjustable articulators; namely Hanau Wide-Vue (arcon) and Dentatus ARH type (non-arcon).

One healthy female patient with intact dentition and no signs and symptoms of TMJ problems was selected for the study. With the help of a custom-made protrusive guide, 10 individual protrusive records for each of the interocclusal recording materials were made. These records were used for programming the two articulators and the respective HCI values were noted. The results obtained were tabulated and subjected to statistical analysis.

The HCI values obtained using each of the interocclusal recording materials in both the semiadjustable articulators was found to be statistically significant. Among the materials polyether gave the highest values with less variability and wax gave low values with greater variation.

The results of this study indicate that HCI values vary both according to the type of interocclusal recording material employed and the articulator selected.

The aim of this in vitro study was to compare the cast metal and ceramic post-core systems, which have similar laboratory and clinical procedures according to coronal microleakage.

Forty extracted maxillary anterior teeth were endodontically treated. Specimens were randomly assigned to four experimental groups (n = 10). The groups consisted of a cemented metal post-core group (CMPC), a not cemented metal post-core group (NMPC), a cemented ceramic post-core group (CZPC) and a not cemented ceramic post-core group (NZPC). A dual-cure resin cement (Panavia F) was used for both of the cemented groups. All specimens were stained with basic fuchsine and embedded in epoxy resin. Sagittal sections were obtained using a grinding machine and examined under binocular and coal microscopes. Coronal leakages were scored and data were analyzed using Kruskall-Wallis analysis of variance test.

Results were compared between and within groups. No statistically significant differences were found between groups.

Cement alone is not sufficient to provide a barrier against microleakage in post-core restorations. The chosen post-core type or application methods may be more relevant to the leakage issue.

The aim of the study was to compare the dimensional stability of dies obtained from addition silicone and polyether impressions that were reheated or subjected to vacuum treatment.

A master die was constructed of a rectangular stainless steel block on to which a photosensitive nylon printing plate attached which contains engraved test grooves. A custom-tray was fabricated and impressions were made using addition silicone and polyether before and after the two treatments. A total of 90 impressions and dies were made from both the elastomers and divided as control group, group I (reheated impressions) and group II (vacuum-treated impressions). A comparative analysis was done to determine which dies yielded the best dimensional accuracy compared to that of the master die.

The minimum percentage dimensional change was observed in test dies made from addition silicone impressions of group I (reheated impressions), followed by the test dies made from polyether impressions in control group. The maximum percentage dimensional change was observed in test dies made from polyether impressions in group I (reheated impressions), followed by the test dies made from addition silicone impressions in group II (vacuum-treated impressions).

The dies obtained from reheated addition silicone impressions yielded the best dimensional stability overall when compared with that of the master die. The dies made of polyether impressions after reheating were not clinically acceptable, because of its hydrophilic nature swelled when they were reheated in a water bath.

Tissue replacement gingival prosthesis is a simple, noninvasive procedure employed to replace large volumes of lost soft tissue architecture while overcoming the pitfalls of surgical treatment modalities. A removable gingival prosthesis has a definite set of superior advantages compared to the extensive surgical treatment options or the employment of a fixed prosthesis. The removable gingival prosthesis helps to render an esthetically pleasing and functional restoration which is economical and less time-consuming for patients who report with large areas of esthetic and functional deficits. This case report highlights the fabrication of a light-weight design of removable gingival veneer to effectively mask the large area of tissue distortion whilst achieving superior esthetics.

Excessive occlusal wear can result in pulpal injury, occlusal disharmony, impaired function and esthetic deformity. Loss of anterior guidance can result from severe wear of anterior teeth, which protects the posterior teeth during excursive movement. The collapse of posterior teeth also results in the loss of normal occlusal plane and the reduction of the vertical dimension. This clinical report describes the use of Hobo Twin- stage procedure for rehabilitation of a patient with severe tooth wear, resulting in reduced VDO.

This article describes the etiological factors and assists the readers in reaching a diagnosis on the type of lesion and their appropriate management.

NCCL: Noncarious cervical lesion; VDO: Vertical dimension at occlusion; RMGIC: Resin-modified glass ionomer cement.

Temporomandibular disorder (TMD) is not just one disorder, but a group of conditions, often painful, that affect the temporomandibular joint, and the muscles that control chewing. Many psychological and physical factors cause myofascial pain, internal derangement of the joint, degenerative joint diseases which ultimately leads to temporomandibular disorder. Scientists are exploring how behavioral, psychological and physical factors may combine to cause temporomandibular disorders and researchers are working to clarify temporomandibular disorders symptoms, with the goal of developing easier and better methods of diagnosis and improved treatment. In part 1 of this 2-part series on temporomandibular disorders, emphasis will be placed on the history and classification of temporomandibular disorders, structure and function of the temporomandibular joint (TMJ), and patient evaluation techniques.

Once proper patient evaluation techniques have been implemented and a working differential diagnosis has been created, the clinician can start treatment planning for the temporomandibular disorder (TMD) patient. This is not an easy task, primarily due to the wide array of treatment options currently available. In the second and final part of this article, focus will be placed on various treatment modalities for temporomandibular disorders.