Overview

Dental implantology is one of the revolutionary specialties in dentistry which has been on the path of advancements for many years. A dental implant not only replaces the missing tooth but is more natural, does not damage the adjacent tooth and maintains the strength of the jaw bone. Much research is being conducted in this field to improve the stability and longevity of dental implants and with the introduction of newer technologies advanced implant designs, materials, and surgical and imaging techniques are being introduced into this field.

Introduction

A dental implant is a long-term and fixed solution for the replacement of missing teeth. It has been used in dentistry for over 50 years and has undergone many modifications and improvements in the design, materials and technology. A lot of research is taking place in this field leading to many recent advances which aim to improve the stability and longevity of dental implants.¹

What are dental implants?

A dental implant is a structure made of alloplastic material (synthetic material) implanted into the oral tissue beneath the mucosa and jaw bone to provide retention and support for a fixed or removable dental prosthesis.²

The components of a dental implant include

• Implant
• Abutment
• Crown 

An implant represents the artificial root structure that is submerged into the jawbone. The abutment acts as a basement for the fixation of the final prosthesis—the artificial tooth and the crown is the final artificial tooth attached.

A dental implant is made of an inert material called Titanium and its alloys. Titanium is one of the most biocompatible materials — a material that does not cause any adverse effect on the living body. For the long-term success of a dental implant, the most important factors are the stability of the bone, lack of infection during the healing period, and maximum integration into the bone.

The stability of the implant can be primary stability or secondary stability. Primary stability is the stability achieved immediately after implant placement and secondary stability is the stability achieved after the bone healing and integration. The process of fusion and integration of bone around the dental implant is called osseointegration and is one of the key factors responsible for the longevity of dental implants.³

Recent technological advancements

Improved materials

Titanium implants: The most commonly used material in dental implants is Titanium and its alloys, particularly the alloy Ti-6Al-4V. Titanium is biocompatible, resistant to corrosion and has better mechanical properties. Even though they have a good track record as a standard implant material their aesthetic value and immunological response may need to be revised since it is a metal. Consequently, researchers began searching for other materials that could be used as dental implants, leading to the development of ceramic implants and implants made of polymers like PEEK.

• Ceramic implants: The most commonly used ceramic implants are Zirconia implants. Zirconia is a white crystalline oxide of zirconium (ZrO2). They are biocompatible, aesthetically superior, reduce the chances of infection and have good mechanical properties and osseointegration⁴
• PEEK implants: Polyetheretherketone (PEEK) implants are one of the advanced materials used for dental implants. These materials are more aesthetic, and biocompatible, can be customised easily and show good integration with the bone⁵
• Surface modifications to enhance osseointegration: Modifying the implant surfaces with techniques like sandblasting, plasma spraying, laser ablation, coating with hydroxyapatite etc. increases the osseointegration — the ability of the implant surface to integrate with the bone thus increasing the success of the implant⁶

Enhanced implant designs

There have been many innovations in the design of implants over the years. Some advances include platform-switched implants, short implants, custom implants using three-dimensional printing, innovations in implant shapes etc. Platform switching is the concept in which smaller abutments than the implant platform is used. Studies show that this technique reduces future bone loss, and improves aesthetics and the long-term success of the implant. 

Short implants are the type of dental implants that can be used in patients where the jaw bone is atrophied and insufficient for conventional implants. Custom-made implants can be used in difficult cases where standard designs cannot be used.⁷

Digital dentistry and 3D printing

Digital dentistry is gaining more popularity these days. Starting from the treatment planning to the final delivery of the prosthesis, dentistry can be fully digitalised. CAD/CAM technology is a computer-assisted technology for designing and manufacturing dental implants, abutments, surgical guides and final prostheses.

3D printing is the process by which objects can be printed three-dimensionally with the help of a digital file. By combining oral scanning  CAD/CAM  designing and 3D printing, customised and more accurate implants, abutments and prostheses can be given to the patient according to the individual needs.⁷

Biological enhancements

Coating the implant surface with bioactive materials like plasma spray coating of hydroxyapatite and Titanium enhance the healing, and bone integration and reduces the chance of infections.⁷ New technologies include coating the implant surface with growth factors like bone morphogenic proteins and growth factor beta to improve bone regeneration around implants.⁸

Immediate loading implants

Conventionally after the implant is placed in the jaw bone, it is left submerged for 3-6 months for the bone to heal and to get integrated around the implant. It is only after this healing period the crown can be attached. With the development of newer technologies and research a new protocol for immediate loading has been introduced.

Immediate loading is defined as restoring the implant in occlusal contact within 48 hours of implant placement Studies claim that the success rate of immediate loading is the same as that of conventional implants depending on factors like adequate primary stability, patient compliance and the number of implants.⁷

Advances in surgical procedures

There are many advances in surgical techniques to reduce recovery time and improve implant stability. Some of them include guided implant surgery, piezoelectric surgery, flapless implant surgery etc. Guided implant surgery is a technique in which imaging technology and machinery aid in the placement of dental implants. By using the imaging technique called CBCT scans specific guides can be prepared for the most accurate, efficient and precise implant placement.⁹

Piezoelectric surgery is a minimally invasive procedure in which special piezoelectric devices are used for implant site preparation and other soft and hard tissue surgical procedures.¹⁰ This ensures faster and better healing and osseointegration around implants with minimum discomfort to the patient. Flapless implant surgery also involves minimum invasion of the soft tissues thus improving and fastening the healing process.

Bone Grafting and Regeneration

Tooth loss is always associated with loss of jaw bone over the years. Bone grafting is the process by which the lost bone is reversed by packing natural or artificial graft materials before the implant surgery. Research and development have introduced new and mechanically strong materials and bone substitutes in this field. Hydroxyapatite (HA), tricalcium phosphate (TCP) and bioglass are some of the new additions to the synthetic bone substitutes. The addition of growth factors and stem cells to these modern bone substitutes increases bone regenerative capacity and osseointegration.¹¹

Enhancing the longevity of dental implants

Maintenance and aftercare

It is important to maintain good oral hygiene and habits for the maximum longevity of dental implants. Regular dental checkups and professional cleaning are also recommended. Research is being conducted to prevent infections around implants by providing antibacterial coatings to the implant surface.

Monitoring and diagnostics

Diagnostic imaging is a crucial part of dental implant treatment. The most commonly used imaging modalities in dental implants are intraoral periapical radiographs, panoramic views and cone beam computed tomography (CBCT). New technologies incorporate artificial intelligence 

into these imaging techniques to make the workflow easier from treatment planning to real-time monitoring and diagnosis of potential issues.¹²

Future directions in dental implant technology

The world of dental implants is constantly changing. Researchers are developing smarter implants that can resist bacteria and generate electricity through chewing and brushing to power tissue-rejuvenating light. The quest for materials and techniques that can provide improved biocompatibility, longevity, and structural integrity is continuing. Groundbreaking technologies, such as 3D printing, regenerative dentistry, nanotechnology, artificial intelligence, can make the entire process of implant treatment more efficient, cheaper, easier and patient-friendly. 

Summary

Dentistry is evolving day by day with the evolution of science and research. A dental implant is a reliable treatment option for replacing a missing tooth. Over the years dental implants have seen various modifications and advances in the field. Even though Titanium is considered the gold standard material in dental implants, new materials like PEEK and Zirconia are revolutionising implant dentistry. Researchers are constantly trying to improve the healing and growth of tissue around dental implants. Surface modifications, biological enhancements, improved design and surgical techniques can ensure the long-term success of dental implants. With the advent of technologies like CAD/CAM, 3D printing, artificial intelligence etc., implant dentistry is revolutionising so that patients can expect a more customised approach and high satisfaction.