Polyoxymethylene

Ver.	Summary	Created by	Modification	Content Size	Created at	Operation
1		Oliver Schierz	+ 390 word(s)	390	2021-04-19 07:43:50	\|
2	Format correct	Vicky Zhou	Meta information modification	390	2021-04-28 03:06:07	\| \|
3	Format correct	Vicky Zhou	+ 1 word(s)	391	2021-04-28 03:07:00	\| \|
4	Format correct	Vicky Zhou	Meta information modification	391	2021-04-29 05:20:01	\|

This entry is adapted from the peer-reviewed paper 10.3390/jcm10071458

Polyoxymethylene (POM) is a material able to provide tooth-colored esthetics and that is suitable for fabrication of frameworks for removable dental prostheses. POM can be characterized as both polyethers (-C-O-) as well as polyacetals (-O-C-O-).

tooth wear bruxism dental restoration wear resin synthetic implant-supported removable partial dentures

Information

Subjects: Dentistry, Oral Surgery & Medicine

Contributor MDPI registered users' name will be linked to their SciProfiles pages. To register with us, please refer to https://encyclopedia.pub/register :

Oliver Schierz

View Times: 2640

Update Date: 29 Apr 2021

Table of Contents

1. Introduction

Polyoxymethylene (POM) is a material able to provide tooth-colored esthetics and that is suitable for fabrication of frameworks for removable dental prostheses (RDPs). POM can be characterized as both polyethers (-C-O-) as well as polyacetals (-O-C-O-) ^[1]. Two formulations of POM are available: the polyoxymethylen homopolymer (POM-H) and copolymer (POM-C). POM-H can be fabricated either from formaldehyde monomers or from trioxane monomers ^[1]. POM-H is a highly crystalline thermoplastic material with a helical structure ^[1]^[2]. For the formulation of POM-C, small amounts of other cyclic ethers (-C-O-) featuring additional methylene groups are added (Figure 1) ^[3]^[4]. The additional methylene groups result in higher thermal and hydrolytic stability, which improves its resistancy against polymer chain degradation ^[5].

Figure 1. Structural formulas of POM-H, POM-C, and corresponding monomers, additional methylene groups (blue).

2. Application

Due to its excellent properties, POM is industrially used as a constructional material, e.g., for the manufacturing of gear wheels, housing parts, and bearings ^[2]^[5]. The favorable mechanical properties include high strength, stiffness, hardness, impact strength, low coefficient of friction, high wear resistance, and dimensional stability ^[2]^[5]^[6]. In addition, POM is featured by high chemical resistance, low water absorption, und high biocompatibility ^[7]^[8]. The melting point of POM ranges around 175 °C. For thermoplastic manufacturing techniques, injection moulding is the most frequently employed process ^[8]. By using subtractive manufacturing, artefacts due to smearing can arise due to excessive cutting temperature levels ^[9]. Additive manufacturing methods such as powder bed fusion have rarely been investigated ^[6]. Recent literature revealed that POM can also be processed via selective laser sintering ^[7]. Regarding the optical appearance, POM is characterized by even surfaces and an intrinsic whiteness. The latter is based on its crystallinity ^[6]^[7]; however, POM can also be colored ^[10]. All in all, favorable properties of POM are advantageous for medical application ^[3]^[7] and the CAD/CAM-techniques pave the way for application in dentistry (overview see Table 1).

Table 1. Advantages and Disadvantages of polyoxymethylene as material for removable dentures.

Advantages	Disadvantages
Tooth-colored, available in different shades	Opaque
Break-proof due to high impact strength	Flexible
Smooth surface	Low chemical interaction with other materials
Non known allergies	Limited wear resistance
Color stability
Customizable color

References

Uchida, T.; Tadokoro, H. Structural studies of polyethers. IV. Structure analysis of the polyoxymethylene molecule by three-dimensional fourier syntheses. J. Polym. Sci. A-2 Polym. Phys. 1967, 5, 63–81.
Samyn, P.; van Driessche, I.; Schoukens, G. Thermal and spectroscopic analysis of worn polyoxymethylene surfaces and wear debris explaining degradation and polymerisation mechanisms. J. Polym. Res. 2007, 14, 411–422.
Eschbach, L. Nonresorbable polymers in bone surgery. Injury 2000, 31, D22–D27.
Klein, R.; Schüll, C.; Berger-Nicoletti, E.; Haubs, M.; Kurz, K.; Frey, H. ABA Triblock Copolymers Based on Linear Poly(oxymethylene) and Hyperbranched Poly(glycerol): Combining Polyacetals and Polyethers. Macromolecules 2013, 46, 8845–8852.
Bergmann, W. Werkstofftechnik. Mit 4 Tabellen: Grundlagen, 7th ed.; Carl Hanser: Munich, Germany, 2013.
Dechet, M.A.; Baumeister, I.; Schmidt, J. Development of Polyoxymethylene Particles via the Solution-Dissolution Process and Application to the Powder Bed Fusion of Polymers. Materials 2020, 13, 1535.
Wendel, B.; Rietzel, D.; Kühnlein, F.; Feulner, R.; Hülder, G.; Schmachtenberg, E. Additive Processing of Polymers. Macromol. Mater. Eng. 2008, 293, 799–809.
Domininghaus, H.; Elsner, P.; Eyerer, P.; Hirth, T. Kunststoffe. Eigenschaften und Anwendungen, 8th ed.; Springer: Berlin/Heidelberg, Germany, 2012; ISBN 9783642161728.
Rubio, J.C.C.; Panzera, T.H.; Scarpa, F. Machining behaviour of three high-performance engineering plastics. Proc. Inst. Mech. Eng. Part B J. Eng. Manuf. 2015, 229, 28–37.
Kaiser, W. Kunststoffchemie für Ingenieure. Von der Synthese bis zur Anwendung, 5th ed.; Carl Hanser: Munich, Germany, 2021.

© Text is available under the terms and conditions of the Creative Commons Attribution (CC BY) license; additional terms may apply. By using this site, you agree to the Terms and Conditions and Privacy Policy.

Upload a video for this entry