Preparation and modifying a new type of waxes


Wissenschaftlicher Aufsatz, 2006

7 Seiten


Leseprobe

ABSTRACT

Aim: To prepare and modify different wax compositions in order to find out the most suitable formula that has almost the same properties of dental modeling wax used in dentistry. Materials and Methods: Three groups of waxes (220 samples) with different compositions regarding its origin (Al-Dora refinery waxes, natural bees wax-North of Iraq, and commercially available Iraqi waxes), additives such as starch, sodium-carboxyl methylcellulose (Na-CMC), rosin, or nylon, and coloring agents were prepared. The samples were tested for their melting range, 21 samples only had a melting range that nearly coincides with that of the dental waxes such as Major and Cavex. Results: The resultant 21 samples were tested for their softening, trimming, penetration, residue materials and solubility. Only 4 samples showed properties that are closely similar to that of Major and Cavex wax. The results of melting point ranged from 69-80oC. Softening test showed that the samples which contain nylon, Na- CMC, or rosin were softened without adhering to the fingers. Trimming test showed that they were trimmed easily and clearly. Penetration test showed that, some samples had the similar measurements of Major and Cavex wax (0.6-0.9mm). Residue materials showed that all samples had no residue of wax materials on acrylic teeth after wax elimination procedure. All the prepared waxes were soluble in ether (acetone), and petroleum spirit (benzene). Conclusion: Six new modeling wax materials were prepared according to ADA specification No.24. Three of new wax materials consist of nylon (polystyrene 1.71-2.13%); the other two novel modeling waxes were fabricated by using additive materials (Na-CMC and rosin).

Key Words: Hard paraffin, natural pure beeswax, dental wax.

Hatim NA, Taqa AA, Abbas WM. Preparation and modifying a new type of waxes. Al-Rafidain Dent J. 2006; 6(1): 64-71.

Received: 1/8/2005Sent to Referees: 11/9/2005Accepted for Publication: 10/11/2005

INTRODUCTION

The major components of dental wax­es may be of minerals, plants, animals, and insects. Waxes may be divided into two categories: Natural waxes (plant, insect

and animal waxes), and synthetic waxes.([1])

Waxes are generally characterized by their thermal properties such as melting point and solid-solid transition temperatu­re that is closely related to the softening temperature observed in practice.([2])

Previously, two types of wax were fo­rmulated in Iraq, boxing wax([3]) and inlay dental wax([4]) from the waxes purchased fr­om Al-Dora Refinery Center, and that av­ailable in the Iraqi market

Another type of wax used in dentistry is modeling wax. It is used as a pattern material for the registration of jaw relatio­nship, also for setting up of artificial teeth in the procedure for a full denture.([1])

Modeling waxes used for clinical pro­cedures should show little or no dimensio­nal changes when they are heated to mouth temperature.([5],[6])

Few formulas are found in the literat­ure for modeling wax. This wax may cont­ain 70 to 80% paraffin-base waxes or co­mmercial ceresin, with small quantities of other waxes, resins, and additives to devel­op the specific qualities desired in the wax.(7–11)

This research aimed to prepare wax, and test some of its properties to find the most suitable dental modeling wax formu­la in comparison with the commercial bra­nds of modeling dental wax used in clinic­al prosthodontic applications, and to prep­are other modeling wax using additive ma­terials.

MATERIALS AND METHODS

The materials used to fabricate new modeling wax materials were listed in Ta­bles (1) and (2).

There is no published information on the percentage, main composition, and ad­ditive materials of modeling wax with its properties.

A pilot study was done to fabricate a novel Iraqi modeling wax material. Two hundred and twenty samples from three gr­oups of waxes with different compositions regarding its origin (Al-Dora refinery wa­xes, natural bees wax, and commercially available Iraqi waxes), additives such as starch, sodium-carboxyl methylcellulose (Na-CMC), rosin, or nylon, were prepar­ed.

Table (1): Materials used to fabricate new waxes

illustration not visible in this excerpt

The samples were tested for their me­lting point. The results of the pilot study showed that 21 samples only had a melting point that nearly coincides with that of the dental waxes such as Major Prodtti Denta­ri SPA, Italy, and Cavex-Italy modeling wax. These tests were done first by mixing 85% of paraffin (hard and soft) wax and 15% additive material. Then novel modeli­ng waxes were fabricated by fixing one percentage of material and change the oth­er components gradually (1% of paraffin and 0.01% of additives). The resultant 21 samples were tested for their softening, tri­mming, penetration, residue materials and solubility. The experimental design of no­vel modeling wax was done according to the following groups:

Group 1: The samples were fabricated fr­om hard paraffin, soft paraffin, and bees wax (natural pure and impure-North of Iraq). These samples were compared with samples consist of additive materials [nyl­on (polystyrene), and ferrous oxide colori­ng agent].

Group 2: The samples were fabricated fr­om commercially available wax materials, and pure bees wax. These samples were compared with samples consist of ad­ditive materials such as rosin, and coloring agent.([11]’ [12])

Group 3: The samples were fabricated fr­om commercially available wax materials, pure beeswax, and additive materials eith­er starch, or Na-CMC, or by adding 5­15% one brand of modeling wax (Major Prodtti Dentari SPA, Italy), and coloring agent.

The new modeling waxes were subjected to the following tests:

1. Melting point.
2. Softening test.
3. Trimming test.
4. Penetration test.
5. Residue material property.
6. Solubility test.

The samples were prepared by the fo­llowing general methods:

The mixing of wax was done by mix­ing different percentages of paraffin wax, and other additives in shaking water bath unit (Kavo GmbH, West Germany) (Figu­re 1) at 45-50°C for five minutes to obtain homogenous mixture liquid. Then the liqu­id mixture was poured in special mold acc­ording to the type of test and left: to cool at room temperature (25 + 2 °C).

Bees wax used in this study was a na­tural wax either pure or impure. Pure bees wax was prepared by adding natural impu­re wax to boiling water, and then cooling the water to 5°C to take the pure wax that floats on the water surface. The addition of coloring agent (ferrous oxide) at 43°C bef­ore melting point was done with mixing.

1. Melting point: The mold used in this test was a cylinder of 2cm in diameter, and 2.5 cm in length to determine the melting point. The melting point was measured according to a method reported by Vogel([13]) using Electro thermal melti­ng point apparatus (CE, VWR. Internati­onal) (Figure 2).

illustration not visible in this excerpt

Figure (1): Shaking water bath unit

illustration not visible in this excerpt

Figure (2): Electro thermal melting
point apparatus.

2. Softening test: The samples were softe­ned to 40-45 °C by the thermostatically controlled water bath unit (Kavo GmbH, West Germany) and tested by finger acc­ording to the ADA Specification No. 24 to determine the adherence of soff wax material.

3. Trimming test: The samples were prep­ared with dimensions 10 mm diameter,
and 6mm thickness (ADA Specification No. 24).([14]) Trimming was done into 6pm cross sections by a microtome (Bright Co. Ltd, Huntingdon, England) at 23 + 2 °C.

[...]

Ende der Leseprobe aus 7 Seiten

Details

Titel
Preparation and modifying a new type of waxes
Autoren
Jahr
2006
Seiten
7
Katalognummer
V207247
ISBN (eBook)
9783656346944
Dateigröße
436 KB
Sprache
Deutsch
Schlagworte
preparation
Arbeit zitieren
Amer Taqa (Autor)Nadira Hatim (Autor)Wafa Abbass (Autor), 2006, Preparation and modifying a new type of waxes, München, GRIN Verlag, https://www.grin.com/document/207247

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