Role of three-dimensional printing in periodontal regeneration and repair: Literature review.

Three-dimensional (3D) printing is the process of building 3D objects by additive manufacturing approach. It is being used in endodontics, periodontology, maxillofacial surgery, prosthodontics, orthodontics, and restorative dentistry, but our review article is focused on periodontal application. A detailed literature search was done on PubMed/Medline and Google Scholar using various key terms. A total of 45 articles were included in this study. Most of the studies were in vitro, preclinical, case reports, retrospective, and prospective studies. Few clinical trials have also been done. Periodontal applications included education models, scaffolds, socket preservation, and sinus and bone augmentation and guided implant placement. It showed better alveolar ridge preservation, better regenerative capabilities, greater reduction in pocket depth and bony fill, ease of implant placement in complex cases with greater precision and reduced time with improved outcome and an important tool for education and training using simulated models. Copyright:

INTRODUCTION

Technology has become an integral part of dentistry in recent years that led to the development of devices and tools to improve treatment methods and teaching in the fields of endodontics, implant, craniofacial, maxillofacial, orthognathic, and periodontal treatments.[1] The increased use of technology or “digital workflow” in dentistry comprises of three elements; acquisition of data through scanning, processing of data using computer-aided design software (CAD), and use the information to build objects using computer-aided-manufacturing.[2] Previously, subtractive manufacturing or milling was used to build objects with some precision, but it was time-consuming, results in wastage of material and limited application in complex anatomy.[3] To overcome these problems three-dimensional (3D) printing was introduced.[3]

3D printing is the term used to describe additive manufacturing approach that builds material layer by layer.[4] It uses the information from CAD software that measures thousands of cross sections to build the exact replica of each product.[4] In dentistry, 3D printing is being used to fabricate stone models, custom impression trays, and dental prosthesis.[4] It is also being investigated to provide tissue scaffolding in bone grafting procedures.[5] Bioprinting is the most common application of additive manufacturing.[6] The advantages include thorough preoperative planning, improved accuracy of fit of prosthesis, and reduction of procedure time.[7] The major demerit is the time and cost spent which renders the justified use of this technology in complex cases only.[7]

Different techniques of 3D printing have been reported in literature with advantages and disadvantage of each technique. Techniques include stereolithography, Photopolymer jetting, selective laser sintering, fused deposition modeling, and powder binder printers. Stereolithography uses laser beam to build object layer by laser from light curable polymerizable resin. It is costly and postprocessing is difficult.[8] Photopolymer jetting include jetting and curing of light cure polymer onto a platform in a layer by layer manner.[8] Different materials can be used such as resin, waxes, and silicon-based materials.[8] It is costly and can cause skin allergy. Selective laser sintering uses heated chamber used to soften powder material and use of laser that fuses heated fine powdered material to build up structures layer by layer.[8] Different materials can be used but need well-developed infrastructure.[8] Fused deposition modeling uses thermoplastic material extruded through nozzle onto the build platform.[8] Powder binder printers use colored water drops from inkjet printer that causes the cement or plaster to set in layer-by-layer manner on an incrementally descending platform.[8]

3D printing has promising application in various fields of dentistry such as orthodontic, endodontic, prosthodontics, maxillofacial surgery, and restorative dentistry but the aim of the present literature review was to document all the English language literature regarding applications of 3D printing in periodontology after detailed and thorough literature search.

METHODOLOGY

A detailed literature search was done on PubMed/Medline and Google Scholar for articles reporting use of 3D printing in endodontics and periodontology, using the key terms: “3D printing,” “rapid prototyping,” “additive manufacturing,” “Dental education,” “Steriolithography,” “3D-printed scaffold,” “periodontal repair,” “periodontal regeneration,” “bioprinting,” “dental materials,” “periodontal ligament (PDL),” “selective laser sintering,” “tissue engineering,” “CAD,” “Guided Tissue Regeneration;” “Alveolar Ridge Augmentation;” “Bioprinting;” and “Sinus Floor Augmentation.”

We included the studies that were published in English language; both human and animal studies were included. All publications focusing on other applications of 3D printing were excluded. A total of 45 articles met the inclusion criteria and included in the review. Details of the included studies are given in Table 1.

Table 1

Literature search on periodontal application of three-dimensional printing

Author	Journal	Type of study	Method	Material	Application	3D printer
Kim et al., 2010[9]	Journal of Dental Research	In vivo animal	3D-printed tooth scaffold	Poly-epsilon caprolactone and hydroxyapatite	Guided tissue regeneration	Not mentioned
Park et al., 2010[10]	Biomaterials	In vivo	3D-printed scaffold	PCL-PGA	Guided tissue regeneration	3D wax-printing system (ModelMaker II, Solidscape, Inc., Merrimack, NH USA)
Carlo Reis et al., 2011[11]	Biomaterials	In vivo	3D-printed scaffold	PLGA/CaP bilayered biomaterial	Guided tissue regeneration	Not mentioned
Park et al., 2012[12]	Biomaterials	In vivo	3D-printed scaffold	Poly-ε caprolactone solution (PCL)	Guided tissue regeneration	3-D rapid prototyping wax printer (ModelMaker II; Solidscape Inc., Merrimack, NH)
Rasperini et al., 2015[13]	Journal of Dental Research	Case report	3D-printed Bioresorbable Scaffold	PCL	Periodontal Repair	Selective laser sintering (Formiga P100 System; EOS e-Manufacturing Solutions)
Sumida et al., 2015[14]	Journal of Craniomaxillofacial Surgery	RCT	3D-printed scaffold	Titanium	Guided bone regeneration	Not mentioned
Obregon and Vaquette, 2012[15]	Biomaterials	In vivo	3D-printed scaffold	Bilayered biomaterial	Guided bone regeneration	Not mentioned
Adel-Khattab et al., 2018[16]	Journal of Tissue Engineering and Regenerative Medicine	In vitro	3D-printed synthetic scaffold	Bioceramic	Guided bone regeneration	R1Series ExOne (PROMETAL, USA)
Park et al., 2014[17]	Journal of dental research	In vivo	3D-printed scaffold	Gelatin, chitosan	Guided tissue regeneration	Not mentioned
Costa et al., 2014[18]	Journal of Clinical Periodontology	In vivo	3D-printed scaffold	Bilayered biomaterial	Guided tissue regeneration	Not mentioned
Pilipchuk et al., 2016[19]	Advance Healthcare Material	Preclinical study	3D-printed scaffold	PCL	Guided tissue regeneration	Not mentioned
Lei et al. 2019[20]	Journal of Oral Implantology	Case report	3D-printed bone model	Not mentioned	Guided tissue regeneration	Not mentioned
Park et al., 2018[21]	Materials (Basel)	In vivo animal study	3D-printed bioresorbable scaffold	PCL	Socket preservation	3D bioprinting system (laboratory -made system in Korea Institute of Machinery and Materials, Daejeon, Korea)
Goh et al., 2015[22]	Clinical oral implants research	pilot randomized controlled clinical trial	3D-printed Bioresorbable Scaffold	PCL	Socket preservation	Fused Deposition Modeling techniques (FDM 3000; Stratasys, Eden Prairie, MN, USA)
Kijartorn et al., 2017[23]	Key engineering materials	Prospective study	3D-printed scaffold	Hydroxyapatite granules	Socket preservation	Projet 160, 3D systems
Tamimi et al., 2009[24]	Biomaterials	Case report	3D-printed monolithic monetite blocks	Synthetic calcium phosphates	Vertical bone augmentation	3D-powder Printing system (Z-Corporation, USA)
Torres et al., 2011[25]	Journal of Clinical Periodontology	In vivo	3D-printed monolithic monetite blocks	A/b-tricalcium phosphate	Vertical bone augmentation	3D-powder printing system (Z-Corporation, USA)
Mangano et al.[26]	Journal of Oral Implantology	In vivo	3D synthetic bone substitute	Ceramic	Sinus augmentation	Not mentioned
Xu et al., 2016[27]	Journal of Prosthodontics	In vitro	Stereolithographic surgical guides	Acrylic	Guided implant placement	Conne×350; Objet, Rehovot, Israel
Sarment et al., 2003[28]	International Journal of Oral and Maxillofacial Implants	In vitro	Stereolithographic templates	Acrylic	Guided implant placement	Mimics; Materialise Technical, Ann Arbor, MI
Ozan et al., 2009[29]	Journal of Oral and Maxillofacial Surgery	Retrospective	3D-printed surgical guide	Acrylic	Guided implant placement	Stereolithography apparatus models and guides (Ay-Tasarim, Kos-gep, ODTU, Ankara, Turkey)
Valente et al., 2009[30]	International Journal of Oral and Maxillofacial Implants	Retrospective study	Stereolithographic templates	Acrylic	Guided implant placement	Simplant
Cassetta et al., 2011[31]	International Journal of Oral and Maxillofacial Surgery	Retrospective	3D-printed surgical guide	Acrylic	Guided implant placement	Stereolithographic surgical guide (External Hex Safe1, Materialise Dental, Leuven, Belgium)
Cassetta et al., 2013[32]	International Journal of Oral Maxillofacial Surgery	Retrospective	3D-printed surgical guide	Acrylic	Guided implant placement	Stereolithographic surgical guide (External Hex Safe1, Materialise Dental, Leuven, Belgium)
Vieira et al., 2013[33]	International Journal of Oral and Maxillofacial Implants	Retrospective	3D-printed surgical guide	Not mentioned	Guided implant placement	Dental slice, bioparts
Lee et al., 2013[34]	Journal of Advance Prosthodontics	Retrospective	3D-printed surgical guide	Not mentioned	Guided implant placement	Conne×350® 3D printing system; Object Geometries Inc., Billerica, MA, USA
Arisan et al., 2013[35]	Clinical Implant Dentistry and Related Research	Prospective	3D-printed surgical guide	Acrylic resin	Guided implant placement	Simplant Pro, Materialise Dental, Leuven, Belgium
Ersoy et al., 2008[36]	Journal of Periodontology	Prospective	3D-printed surgical guide	Acrylic resin	Guided implant placement	Ay-Design, Kos-gep, ODTU, Ankara, Turkey
Verhamme et al., 2015[37]	Clinical Implant Dentistry and Related Research	Prospective	3D-printed surgical guide	Not mentioned	Guided implant placement	NobelGuide (Nobel Biocare, Gothenburg, Sweden
Vasak et al., 2011[38]	Clinicl Oral Implants Research	Prospective	3D-printed surgical guide	Not mentioned	Guided implant placement	NobelGuide (Nobel Biocare, Gothenburg, Sweden
Stübinger et al., 2014[39]	Clinical Implant Dentistry and Related Research	Prospective	3D-printed surgical guide	Polymer	Guided implant placement	Astra Tech AB, Mölndal, Sweden
Di Giacomo et al., 2012[40]	Journal of Periodontology	Prospective	3D-printed surgical guide	Not mentioned	Guided implant placement	Sinterstation HiQ, 3D Systems, Rock Hill, SC
D’haese et al., 2012[41]	Clinical Implant Dentistry and Related Research	Clinical trial	Stereolithographic surgical guides	Not mentioned	Guided implant placement	Materialise N.V., Leuven, Belgium
Van Assche et al., 2010[42]	Journal of Clinical periodontology	Clinical trial	Stereolithographic surgical guides	Not mentioned	Guided implant placement	Procera® software (Nobel Biocare AB, Göteburg, Sweden)
Van de Wiele et al., 2015[43]	Clinical Oral Implants Research	Clinical trial	Stereolithographic surgical guides	Not mentioned	Guided implant placement	Implant Safe Guide, Dentsply Implants
Pozzi et al., 2014[44]	European Journal of Oral Implantology	Clinical trial	Stereolithographic surgical guides	Acrylic resin	Guided implant placement	Nobel Procera, Nobel Biocare
Arisan et al., 2010[45]	Clinical Oral Implants Research	Clinical trial	Stereolithographic surgical guides	Acrylic resin	Guided implant placement	Aytasarim (Classic and Otede systems), Kos-gep, ODTU, Ankara, Turkey SimPlant (SurgiGuide and SAFE systems), Materialise Dental.
Abboud et al., 2012[46]	International Journal of Oral and Maxillofacial Implants	NRCT	Stereolithographic surgical guides	Acrylic	Guided implant placement	Materialise SimPlant system or the Nobel Biocare system
Di Giacomo et al., 2005[47]	Journal of Periodontology.	NRCT	Stereolithographic surgical guides	Polymer	Guided implant placement	Sim plant CSI Materialise, Ann Arbor, MI
Mangano et.al., 2018[48]	International Journal of Environmental Research and Public Health	NRCT	Stereolithographic surgical guides	Polymer	Guided implant placement	3D printer (XFAB2000®, DWS).
Lindeboom et al., 2010[49]	Clinical Oral Implants Research	RCT	Stereolithographic surgical guides	Acrylic	Guided implant placement	Procera® Software 3D Planning Program (Nobel Biocare AB, Göteborg, Sweden)
Bernard et al. 2019[50]	Journal of Prosthetic Dentistry	RCT	Stereolithographic surgical guides	Acrylic	Guided implant placement	Simplant; Materialise Dental
Younes et al.[51]	Clinical Oral Implants Research	RCT	Stereolithographic templates	Acrylic	Guided implant placement	Not mentioned
Vercruyssen et al., 2014[52]	Journal of Clinical Periodontology	RCT	Stereolithographic templates	Acrylic	Guided implant placement	Materialise Dental
Shen et al., 2015[53]	Journal of Craniomaxillofacial Surgery	RCT	Stereolithographic templates	Acrylic	Guided implant placement	Geomagic, version 10.0, Geomagic, Research triangle Park, NC

3D – Three dimensional; PCL – Polycaprolactone; PGA – Polyglycolic acid; PLGA – Polylactide-co-glycolide acid; CaP – Calcium phosphate; RCT – Randomized controlled trial

CLINICAL APPLICATION OF THREE-DIMENSIONAL PRINTING

Periodontal applications of three-dimensional printing

Uses of 3D printing in periodontology include bio-resorbable scaffold for periodontal repair and regeneration, socket preservation, bone and sinus augmentations procedures, guided implant placement, peri-implant maintenance, and implant education. All these applications are discussed in detail in the following paragraphs.

Three-dimensional printed bioresorbable scaffold for guided bone and tissue regeneration

Recent advancement in the field of tissue engineering has led to the development of “3D printed” scaffolds. These multiphasic scaffolds consisting of both hard (bone and cementum) and soft tissues (gingiva and PDL) components of the periodontium, are not only specific for the particular tissue but are also competent mechanically.[54] With the increasing demand for tissue regeneration, these scaffolds have been investigated in different periodontal procedures such as socket preservation, guided tissue and bone regeneration, sinus, and vertical bone augmentation.[5556]

The purpose of these scaffolds is to promote the formation of bone, PDL, cementum, and reestablishment of connection between them. Among various materials, polycaprolactone has been widely used as a scaffold material due to its documented successful outcomes in bony regeneration.[57] The advantages of these scaffolds include 3D architecture that closely resemble extracellular matrix resulting in better regenerative capabilities.[58]

Literature search revealed that most of the studies done were preclinical, in vivo, in vitro and case reports describing promising results in the field of periodontal regeneration.[91011121315161718192021] Rasperini et al.[13] first time reported the use of 3D-printed scaffold in human periodontal defect (labial soft and hard tissue dehiscence). The results of this case report showed favorable results up to 12 months but failed afterward. Lei et al.[20] also reported a 15-month follow-up case of guided tissue regeneration using 3D-printed scaffold and platelet-rich fibrin in the management of bony defect around maxillary lateral incisor. He reported significant reduction in pocket depth and bony fill. In a randomized clinical trial by Sumida et al., used 3D-printed custom-made device for bone defect and reported shorter procedure time and need few screw for retention than commercial mesh group.[14] There is a lack of randomized control trials and clinical studies with long-term follow-up.

Socket preservation

The removal of tooth leads to loss of width and height of alveolar ridge due to the natural process of resorption. It has been reported in a systematic review that after tooth extraction, average reduction in alveolar bone width and height was 3.87 mm and 1.67 mm, respectively.[59] Recent advancement in technology has allowed the use of 3D-printed scaffold to preserve socket and maintain the dimension of the extraction socket. Park et al. reported a study on beagle dogs reported a predictable outcome with the use of 3D-printed polycaprolactone in socket preservation.[21] A pilot randomized controlled clinical trial by Goh et al.[22] reported the use of 3D-printed bioresorbable scaffold in socket preservation and reported normal bone healing and significantly better alveolar ridge preservation when compared to extraction socket without scaffold after 6 months. Kijartorn et al.[23] also reported in a prospective cohort that 3D-printed hydroxyapatite has potential advantages when used as bone graft material in socket preservation. Clinical studies with long-term follow-up are missing and need consideration.

Sinus and bone augmentation

Loss of vertical bone height is a common sequel after tooth extraction that ultimately affects the treatment of partially dentate patients, especially for implant placement that requires adequate bone height and width.[24] Maxillary sinus position also limits the available bone height.[24] Various methods have been reported in literature for bone and sinus augmentation such as bone grafting, distraction osteogenesis, and guided bone regeneration. Recent advancement in technology has introduced the role of 3D printing in bone and sinus augmentation and has shown positive outcomes.

One of the advantages of 3D printing is the ability to replicate the bony architecture and form macroporous internal structure of graft with minimal wastage of material because of the additive manufacturing technique. Other advantages include no ethical concerns, ample availability due to alloplastic material, less risk of infection transfer, and less chair side time of surgery.[60] There is a lack of randomized control trial, however, multiple case reports and in vivo studies have reported successful outcome after use of 3D scaffold for sinus and bone augmentation.[2426]

Studies have reported the effective use of various materials for printing bone graft, including monolithic monetite (dicalcium phosphate anhydrous), biphasic calcium phosphate.[25]

Three-dimensional printing for implants placement

Implant placement is a routine procedure done by dental professionals to replace missing teeth due to its predictable outcomes.[61] Implant placement is a technically demanding procedure and if not done properly, can lead to various complications such as poor esthetics, damage to anatomically important structures, infections, and implant failure.[62] Guided implant placement can prevent these complications by fabrication of surgical guides with the help of 3D printing. It helps in accurate 3D placement of implant thus preventing unwanted damage to anatomic structures and reduce time.

Multiple studies including, in vitro, in vivo, case reports, prospective and retrospective studies and several clinical trials have been done on guided implant placement and have reported positive outcomes.[27282933454651] Details of the studies are given in Table 1.

Two protocols of guided implant surgery have been described in literature, static, and dynamic.[63] Static guide also called stereo-lithographic guide use the static surgical template and does not allow any changes in planned implant position during surgery, whereas dynamic approach use motion tracking technology and allow changes in implant positioning. The guides are produced using photopolymerization techniques.[64] The static approach is more commonly employed as it is less costly and less technique sensitive and both protocols have comparable failure rates.[63] Surgical guides can be supported by teeth, mucosa, bone, and pin or mini implants depending on the intraoral condition like partially dentate or edentulous and need for extensive bone surgery.[63] Tahmaseb et al. reported in a systematic review that the use of miniimplants result in more accurate implant placement and immediate loading is possible.[63]

Common complications in guided implant surgery include guide breakage during surgery, positioning error, and early implant loss due to inadequate primary stability.[65]

Studies report that using 3D-surgical guide precise implant placement is possible in partially and completely edentulous patients even using flapless approach, reducing chairside surgical time, and patient comfort postsurgery and also allow simultaneous implant placement in complex cases.[282930333638424548] Studies have also reported that care should be taken while using 3D-printed template because angular and linear deviations are possible and have advised use of bone supported surgical guide rather than mucosa or tooth supported along with additional bone pins, sharp drill, physical drill stop, and at least three fixation screws in tripod arrangement to increase the stability of the guide and minimize inaccuracies[27313234353740414766] Despite the advantages the surgeon should not over-rely on 3D-printed guide for surgical safety and caution should be taken.[39] Cost is a factor when using 3D-printed template, but studies have reported it as justified.[51] Studies have that there was no significant difference in terms of patient-related outcome both clinical and radiographic at 1 year and 3 years’ follow-up between guided and nonguided surgery.[5052] Van de Wiele et al. Reported, that nonexperience clinicians can also accurately place an implant if supervised by experienced dentists.[43]

Use of three-dimensional printing for peri-implant maintenance

Implant surfaces are different and require special attention while cleaning and maintaining. No published literature has been found on this topic however we found one book in which the author reported that 3D-printed implant models can be used to teach implant maintenance to patients.[67]

Use of three-dimensional printing for implant education

3D printing can be used for education purpose that includes patient understanding of the procedure before giving consent for implant placement on 3D-printed model. It helps to reduce anxiety of patient. These model also help in the training of undergraduate and postgraduate students regarding implant treatment planning, placement of implant without affecting the nearby anatomic structures.[67]

CONCLUSION

3D printing has revolutionized the field of periodontology. Various uses of this technology have been reported in literature in various fields including 3D-printed scaffold for socket preservation, periodontal repair and regeneration, and sinus and bone augmentation, peri-implant maintenance, and implant education. 3D-printed scaffolds show predictable outcome for bone and tissue regeneration as well as sinus and bone augmentation. Implant placement using 3D printing surgical template increases the accuracy, reduces deviation in position, incidence of complications, surgical time, postoperative pain, and swelling. 3D-printed models have a promising role as an education tool. Extra cost and time are the limiting factors. Although the use of 3D printing is of prime focus for periodontist, documented literature is limited to preclinical studies, case reports, and few clinical trials. Future implications need more good quality randomized control trials.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.