Metallic Dental Implants Wear Mechanisms, Materials, and Manufacturing Processes: A Literature Review

Abstract

Objectives: From the treatment of damaged teeth to replacing missing teeth, dental biomaterials cover the scientific interest of many fields. Dental biomaterials are one of the implants whose effective life depends vastly on their material and manufacturing techniques. The purpose of this review is to summarize the important aspects for metallic dental implants from biomedical, mechanical and materials science perspectives. The review article will focus on five major aspects as mentioned below. Tooth anatomy: Maximizing the implant performance depends on proper understanding of human tooth anatomy and the failure behavior of the implants. Major parts from tooth anatomy including saliva characteristics are explored in this section. Wear mechanisms: The prominent wear mechanisms having a high impact on dental wear are abrasive, adhesive, fatigue and corrosion wear. To imitate the physiological working condition of dental implants, reports on the broad range of mastication force and various composition of artificial saliva have been included in this section, which can affect the tribo-corrosion behavior of dental implants. Dental implants classifications: The review paper includes a dedicated discussion on major dental implants types and their details for better understanding their applicability and characteristics. Implant materials: As of today, the most established dental implant materials are SS316L, cobalt chrome alloy and titanium. Detailed discussion on their material properties, microstructures, phase transformations and chemical compositions have been discussed here. Manufacturing techniques: In terms of different production methods, the lost wax casting method as traditional manufacturing is considered. Selective Laser Melting (SLM) and Directed Energy Deposition (DED) as additive manufacturing techniques (AM) have been discussed. For AM, the relationships between process–property–performance details have been explored briefly. The effectiveness of different manufacturing techniques was compared based on porosity distribution, mechanical and biomechanical properties. Summary: Despite having substantial research available on dental implants, there is a lack of systematic reviews to present a holistic viewpoint combining state-of-the-art from biomedical, mechanical, materials science and manufacturing perspectives. This review article attempts to combine a wide variety of analyzing approaches from those interdisciplinary fields to deliver deeper insights to researchers both in academia and industry to develop next-generation dental implants.

Fatigue life estimation of dental implants using a combination of the finite element method and traditional fatigue criteria

“…[4][5][6] However, even though all these conditions are met, the implants can still fail. 7 A long-term cohort study reported that 31% of the surveyed patients presented an implant with a mechanical fracture, against only 16.9% with biological complications. 8 It is widely known that, due to the chewing movements, speaking, etc, the dental prosthesis is under cyclical loading.…”

“…Therefore, it could be concluded that although it might lack physical-clinical-visible pieces of evidence, there is a large potential for failures due to fatigue as these might be a consequence of micro-cracks and localized wear. 7,10,15,16 The consequences of a failure by fatigue may include, in addition to a sudden failure of the implant, the generation of micro-cracks, in which bacteria can house inside them, inflaming the surrounding tissue and impairing the osseointegration process and prosthesis stability. Unfortunately, up to date, there is not a feasible clinical method for an inspection on implant fatigue integrity.…”

“…4–6 However, even though all these conditions are met, the implants can still fail. 7 A long-term cohort study reported that 31% of the surveyed patients presented an implant with a mechanical fracture, against only 16.9% with biological complications. 8…”

“…Therefore, it could be concluded that although it might lack physical-clinical-visible pieces of evidence, there is a large potential for failures due to fatigue as these might be a consequence of micro-cracks and localized wear. 7,10,15,16…”

Tailoring Ti Grade 2 and TNTZ alloy surfaces in a two-step mechanical–chemical modification

“…Some of those requirements can only be met by metallic materials. This is due to their properties such as good corrosion resistance, high static and fatigue strength, and fracture toughness [1][2][3][4]. However, there are other requirements, as well, including biocompatibility, bioactivity, and non-toxicity [2,3].…”