Resin Nanoceramic CAD/CAM Restoration of the Primary Molar: 3-Year Follow-Up Study.
Third molar teeth aside, mandibular second premolars are the most common congenitally absent teeth [1-3]. In such cases, treatment planning is affected by a variety of factors, including patient age, developmental levels of adjacent teeth, facial profile, arch length, incisor inclination, jaw protrusion, degree of infraocclusion in persistent deciduous teeth, and root resorption [1, 3].
When a persistent deciduous tooth is extracted at an early stage (ages 8-9), the resultant space can undergo spontaneous closure through mesial movement of adjacent teeth. However, this can only occur if the first permanent molar root-formation is incomplete [4-6]. Moreover, extraction is not recommended in patients with generalized spacing of teeth, deep-bite, hyperdivergent facial profile, or mandibular retrusion because it will damage the facial profile . In older patients, the extraction space can be closed orthodontically [1, 8] or restored with a prosthetic tooth implant or autotransplantation after the completion of growth [1, 5, 9, 10].
If there is no specific indication for extraction, another treatment alternative is to leave the persistent deciduous tooth in place, if the tooth has good (or at least acceptable) crown-root structure, functionality, and aesthetics. This treatment preserves the integrity of the alveolar bone for a future implant procedure . However, because the space resulting from the extraction of a primary molar tooth tends to be too wide for a premolar implant as well as too narrow for a molar implant [8, 11, 12], reducing the mesiodistal width of the retained deciduous molar to that of a second permanent premolar and allowing for spontaneous closure of the remaining minor space through mesial movement of adjacent teeth are recommended [8, 12].
Because mesiodistal reduction of the deciduous tooth leaves it with exposed dentin that is prone to dental caries, composite restoration of the exposed dentin surface is recommended as a preventative measure . However, composite restoration entails the risk of marginal leakage and colorization over the long term . Computer-aided design or computer-aided manufacturing (CAD/CAM) offers a restoration method that decreases the risk of human error and provides highly aesthetic outcomes, albeit with relatively high costs . Initially, ceramicblocks were used [15, 16], but today they have been largely replaced by composite blocks [16-18] that are easier to process and repair and cause much less abrasion of teeth in the opposing arch [18-20]. While CAD/CAM restoration has become a common method of treatment for permanent teeth in children, there are only a limited numbers of case reports on its use in deciduous teeth .
The case report below presents the clinical use of a resin nanoceramic CAD/CAM restoration of a primary second premolar without successor in the form of a permanent second premolar tooth in a patient.
2. Case Report
A 13-year-old female patient presented at the Department of Pedodontics, Faculty of Dentistry, Ankara University, complaining of the delated eruption of a permanent tooth. The patient's medical history indicated that one month earlier she had received antibiotics to treat an abscess of the right mandibular primary second molar tooth. Clinical examination showed deep dentinal caries and a 1 mm infraocclusion when compared to the adjacent teeth (Figure 1(a)). Radiographic examination showed no permanent tooth germ under the primary second molar, no periradicular lesion, and uniform bone between the primary second molar tooth and the first permanent premolar (Figures 1(b) and 1(c)). Both clinical and radiographic examinations showed no ankylosis. Additionally, on the other quadrant, congenital agenesis of lower second premolar was observed and primary second molar was previously extracted (Figure 3(a)). As a result of this extraction, mesialization of permanent first molar was seen and residual space was in size of second premolar mesiodistal dimension. The patient had a Class I molar relationship. Given the patient's age, a treatment plan that included extraction of right primary second molar followed by orthodontic treatment to close the extraction gaps was recommended; however, this plan was rejected by the patient. An alternative treatment option described below was presented to the parents, and after approval written consent was obtained for treatment.
Pulpectomy was performed as described below. Inferior alveolar nerve block was administered (2% lidocaine with 1: 100.000 adrenaline), the tooth was isolated with a rubber dam, the pulp chamber was accessed, and the working length was determined using a Size 15 sterile K-file to 2 mm short of the radiographic apex. Intracanal tissue was extirpated using a barbed broach (Medin Barbed Broach, Vlachovice, Czech Republic), and the canals were filed with K-Flexofiles until a master file size of 30 was reached (G-star Medical Co., Ltd., Guangdong, China). Canals were irrigated with 2 ml of 1% sodium hypochlorite (NaOCl) between instruments and with 5 ml of sterile saline as a final irrigation. Canals were dried with premeasured paper points up to 2 mm from the root apices. Canals were filled with white mineral trioxide aggregate (WMTA) (ProRoot, Dentsply, Tulsa Dental, OK, USA) prepared according to the manufacturer's instructions using a lentulo and hand tools. After radiographic control of the root-canal filling, a wet cotton pellet was applied to the pulp chamber, and the access cavity was sealed with glass ionomer cement (Ionofil Plus, Voco, Cuxhaven, Germany). Two days later, the cotton pellet was removed, and the cavity was restored with glass ionomer cement and compomer (Dyract XP, Dentsply, Tulsa Dental, OK, USA).
In order to accommodate any future dental implant that might be required in the event of the loss of the retained primary molar, it is planned to restore the tooth RNC CAD/CAM by reducing mesiodistal width in the form of a permanent premolar. The deciduous tooth was prepared according to standardized preparation techniques with a chamfered margin. The size of the reduction was determined according to the mesiodistal and buccolingual measurements of the erupted opposite first permanent premolar tooth (mesiodistal: 8 mm; buccolingual: 8 mm). Measurements were obtained using a digital camera (Cerec AC, Bluecam, Germany), and the crown was formed from a nanoresin ceramic block (3M Lava Ultimate, United States) with milling method (Cerec MC XL Premium, Germany). The finished crown was cemented using water-based adhesive cement (Adhesor Carbofine, Spofa Dental, Czech Republic) (Figure 2). Finally, a removable space maintainer was applied for left edentulous space (Figure 3(b)).
Regular clinical and radiographic follow-ups were conducted every six months for three years (Figure 4). Clinical examination included evaluation of sensitivity to percussion and palpation, soft-tissue pathology, infraocclusion and marginal fitness, and integrity of the crown restoration. Radiographic examination included evaluation of internal and external root resorption, periradicular lesions, and ankylosis. No clinical or radiographic pathology was observed at any time during the follow-up period.
Three-year follow-up of the case revealed that resin nanoceramic CAD/CAM restoration of the primary molar without successor achieved both aesthetics and function.
While primary second molar teeth without successors are known to remain serviceable for manyyears , if extraction is required in the future, a dental implant may be indicated [22, 23]. Successful implant treatment requires an adequate amount of bone volume mesiodistally as well as buccolingually . Without adequate bone, a graft maybe required, which involves additional financial costs as well as treatment time . A retained primary tooth offers the advantage of helping to preserve bone and soft-tissue structure ; however, in view of the possible need for future implant treatment, reshaping the retained tooth to resemble a permanent premolar is recommended in order to reduce the mesiodistal width [8, 11]. In the case presented here, the decision was made to restore the second primary molar in order to avoid supraeruption of the maxillary teeth, achieve normal occlusion, and restore function and aesthetics.
In the case presented here, the decision was made to perform root-canal treatment for the second primary molar tooth because of the abscess formation history. In general, a resorbable paste or a combination of pastes such as zinc oxide eugenol (ZOE), iodoform, and calcium hydroxide is used for primary tooth pulpectomy ; however, in the case of a primary tooth without a successor, a nonresorbable material is recommended [26, 27]. Previous studies have reported success with a combination of gutta-percha and ZOE sealer  and with mineral trioxide aggregate (MTA) [26, 29]. In this case, MTA was selected as a root-filling material because of its biocompatibility, excellent sealing ability, and long-term better prognosis than gutta-percha and ZOE sealer .
Dental composites, stainless steel crowns, and gold onlays can all be used to restore and reshape second primary molars without successors [11, 30, 31]. However, composite resin restorations still have the drawbacks of marginal leakage and color changes with foods and beverages, whereas stainless steel crowns offer poor aesthetics [13, 32, 33]. In the case presented here, due to the continuing growth of the patient, the restoration was expected to remain in service for approximately 5 years until implant placement; therefore, a resin CAD/CAM restoration was performed.
Unlike composite restorations, resin nanoceramic blocks offer optimized mechanical properties with a higher degree of monomer polymerization and less abrasion of the opposing dental arch when compared to ceramic restorations; they are also easily repaired using composite resin, if necessary . While the aesthetic advantages of full ceramic restorations are well known , resin nanoceramic (Lava Ultimate) restorations also have excellent aesthetic results . For this reason, a CAD/CAM Cerec composite block was used in the present case to reshape a primary second molar to mimic the morphology of a permanent second premolar.
Three-year follow-up of the case revealed that resin nanoceramic CAD/CAM restoration of the primary molar without successor achieved both aesthetics and function. However, longer follow-up is needed to evaluate for a possible ankylosis formation in the future. The patient's occlusion will be suitable for an implant restoration if needed in the future.
As this case report clearly shows, agenesis of a permanent mandibular second premolar can be treated by reshaping a retained second primary molar using a resin nanoceramic CAD/CAM restoration to achieve good function and esthetics. Despite the high cost of treatment, this alternative should be considered if the retained tooth is expected to maintain functionality over the long term. Despite the high cost of treatment, this type of restoration should be considered if the retained tooth is expected to maintain functionality over the long term.
Conflicts of Interest
All the authors have no conflicts of interest to declare.
 C. D. Fines, J. Rebellato, and M. Saiar, "Congenitally missing mandibular second premolar: treatment outcome with orthodontic space closure," American Journal of Orthodontics and Dentofacial Orthopedics, vol. 123, no. 6, pp. 676-682, 2003.
 B. J. Polder, M. A. Van't Hof, F. P. G. M. Van Der Linden, and A. M. Kuijpers-Jagtman, "A meta-analysis of the prevalence of dental agenesis of permanent teeth," Community Dentistry and Oral Epidemiology, vol. 32, no. 3, pp. 217-226, 2004.
 P. Ngan, D. Heinrichs, and S. Hodnett, "Early management of congenitally missing mandibular second premolars: a review," Hong Kong Dental Journal, vol. 8, no. 1, pp. 40-45, 2011.
 A. Mamopoulou, U. Hagg, U. Schroder, and K. Hansen, "Agenesis of mandibular second premolars. Spontaneous space closure after extraction therapy: a 4-year follow-up," European Journal of Orthodontics, vol. 18, no. 6, pp. 589-600, 1996.
 L. L. Santos, "Treatment planning in the presence of congenitally absent second premolars: a review of the literature," Journal of Clinical Pediatric Dentistry, vol. 27, no. 1, pp. 13-17, 2003.
 R. Valencia, M. Saadia, and G. Grinberg, "Controlled slicing in the management of congenitally missing second premolars," American Journal of Orthodontics and Dentofacial Orthopedics, vol. 125, no. 5, pp. 537-543, 2004.
 K. Bjerklin, M. Al-Najjar, H. KArestedt, and A. Andren, "Agenesis of mandibular second premolars with retained primary molars. A longitudinal radiographic study of 99 subjects from 12 years of age to adulthood," European Journal of Orthodontics, vol. 30, no. 3, pp. 254-261, 2008.
 V. G. Kokich and V. O. Kokich, "Congenitally missing mandibular second premolars: Clinical options," American Journal of Orthodontics and Dentofacial Orthopedics, vol. 130, no. 4, pp. 437-444, 2006.
 G. Zuccati, "Implant therapy in cases of agenesis," Journal of Clinical Orthodontics, vol. 27, no. 7, pp. 369-373, 1993.
 K. Bjerklin and J. Bennett, "The long-term survival of lower second primary molars in subjects with agenesis of the premolars," European Journal of Orthodontics, vol. 22, no. 3, pp. 245-255, 2000.
 S. Robinson and M. F. W.-Y. Chan, "New teeth from old: treatment options for retained primary teeth," British Dental Journal, vol. 207, no. 7, pp. 315-320, 2009.
 F. M. Spear, D. M. Mathezus, and V G. Kokich, "Interdisciplinary management of single-tooth implants," Seminars in Orthodontics, vol. 3, no. 1, pp. 45-72, 1997.
 A. Khatri, B. Nandlal, and N. Marwah, "Staining of a conventional and a nanofilled composite resin exposed in vitro to liquid ingested by children," International Journal of Clinical Pediatric Dentistry, vol. 3, pp. 183-188, 2010.
 G. C. Santos Jr., M. J. Santos Jr., A. S. Rizkalla, D. A. Madani, and O. El-Mowafy, "Overview of CEREC CAD/CAM chairside system," General Dentistry, vol. 61, no. 1, pp. 36-40, 2013.
 E. A. Mclaren and D. A. Terry, "CAD/CAM systems, materials, and clinical guidelines for all-ceramic crowns and fixed partial dentures," Compend Contin Educ Dent, vol. 23, pp. 637-641, 2002.
 G. T. Rocca, F. Bonnafous, N. Rizcalla, and I. Krejci, "A technique to improve the esthetic aspects of CAD/CAM composite resin restorations," Journal of Prosthetic Dentistry, vol. 104, no. 4, pp. 273-275, 2010.
 C. Chen, F. Z. Trindade, N. De Jager, C. J. Kleverlaan, and A. J. Feilzer, "The fracture resistance of a CAD/CAM Resin Nano Ceramic (RNC) and a CAD ceramic at different thicknesses," Dental Materials, vol. 30, no. 9, pp. 954-962, 2014.
 N. D. Ruse and M. J. Sadoun, "Resin-composite blocks for dental CAD/CAM applications," Journal of Dental Research, vol. 93, no. 12, pp. 1232-1234, 2014.
 A. S. Kassem, O. Atta, and O. El-Mowafy, "Fatigue resistance and microleakage of CAD/CAM ceramic and composite molar crowns," Journal of Prosthodontics, vol. 21, no. 1, pp. 28-32, 2012.
 J. Nguyen, V. Migonney, N. D. Ruse, and M. Sadoun, "Resin composite blocks via high-pressure high-temperature polymerization," Dental Materials, vol. 28, no. 5, pp. 529-534, 2012.
 S. M. Stines, "Pediatric CAD/CAM applications for the general practitioner: part 1," Dentistry Today, vol. 27, no. 9, pp. 130-133, 2008.
 P. D. Ledermann, T. M. Hassell, and A. F. Hefti, "Osseointegrated dental implants as alternative therapy to bridge construction or orthodontics in young patients: seven years of clinical experience," Pediatric Dentistry, vol. 15, no. 5, pp. 327-333, 1993.
 B. Abbo and M. E. Razzoog, "Management of a patient with hypodontia, using implants and all-ceramic restorations: a clinical report," Journal of Prosthetic Dentistry, vol. 95, no. 3, pp. 186-189, 2006.
 B. Thilander, "Orthodontic space closure versus implant placement in subjects with missing teeth," Journal of Oral Rehabilitation, vol. 35, no. 1, pp. 64-71, 2008.
 J. H. Camp, E. J. Barrett, and F. Pulver, "Pediatric endodontics: endodontic treatment for the primary and young permanent dentition," in Pathways of the Pulp, S. Cohen and R. C. Burns, Eds., pp. 797-844, Mosby, St. Louis, Mo, USA, 2002.
 E. S. Tunc and S. Bayrak, "Usage of white mineral trioxide aggregate in a non-vital primary molar with no permanent successor," Australian Dental Journal, vol. 55, no. 1, pp. 92-95, 2010.
 T. Bezgin, B. M. Ozgul, V. Arikan, and S. Sari, "Root canal filling in primary molars without successors: mineral trioxide aggregate versus gutta-percha/AH-Plus," Australian Endodontic Journal, vol. 42, no. 2, pp. 73-81, 2016.
 G. Ansari and Mirkarimi, "Gutta percha root filling in 2nd primary molar teeth with missing successor: a challenging approach," Research Journal of Medical Sciences, vol. 2, no. 5, pp. 251-254, 2008.
 S. M. O'Sullivan and G. R. Hartwell, "Obturation of a retained primary mandibular second molar using mineral trioxide aggregate: a case report," Journal of Endodontics, vol. 27, no. 11, pp. 703-705, 2001.
 R. D. Evans and P. F. Briggs, "Restoration of an infra-occluded primary molar with an indirect composite onlay: a case report and literature review," Dental Update, vol. 23, no. 2, pp. 52-54, 1996.
 L. Giachetti, F. Bertini, and D. Landi, "Morphological and functional rehabilitation of severely infra-occluded primary molars in the presence of aplasia of the permanent premolar: a clinical report," Journal of Prosthetic Dentistry, vol. 93, no. 2, pp. 121-124, 2005.
 M. Mohan, Z. Shey, J. Vaidyanathan, T. K. Vaidyanathan, S. Munisamy, and M. Janal, "Color changes of restorative materials exposed in vitro to cola beverage," Pediatric Dentistry, vol. 30, no. 4, pp. 309-316, 2008.
 E. Mahoney, N. Kilpatrick, S. Hibbert, and J. Timothy, "Restorative paediatric dentistry," in Handbook of Pediatric Dentistry, A. C. Cameron and R. P. Widmer, Eds., pp. 79-102, Mosby Elsevier, 2013.
 G. Arnetzl, M. Koller, G. V. Arnetzl, and L. Holly, "Lava ultimate resin nano ceramic for CAD/CAM: customization case study," International Journal of Computerized Dentistry, vol. 15, no. 2, pp. 159-164, 2012.
Akif Demirel, (1) Tugba Bezgin, (1) Funda Akaltan, (2) and Saziye Sari (1)
(1) Department of Pediatric Dentistry, Faculty of Dentistry, Ankara University, Ankara, Turkey
(2) Department of Prosthodontics, Faculty of Dentistry, Ankara University, Ankara, Turkey
Correspondence should be addressed to Akif Demirel; firstname.lastname@example.org
Received 19 April 2017; Accepted 25 May 2017; Published 20 June 2017
Academic Editor: Ali I. Abdalla
Caption: Figure 1: Preoperative intraoral and radiographic views of the patient. (a) Preoperative intraoral view. (b) Preoperative periapical radiograph. (c) Postoperative radiograph after root-canal treatment.
Caption: Figure 2: Crown preparation and cementation. (a) Tooth preparation with chamfered margin. (b-d) Intraoral views of the crown after cementation. (e) Postoperative radiograph of the crown.
Caption: Figure 3: Intraoral view of left primary second molar extraction space (a). Removable space maintainer for space maintenance (b).
Caption: Figure 4: Follow-up views: (a) 1-year follow-up radiograph; (b) 2-year follow-up radiograph; (c) 3-year follow-up radiograph; (d) 3-year follow-up intraoral view.
|Printer friendly Cite/link Email Feedback|
|Title Annotation:||Case Report|
|Author:||Demirel, Akif; Bezgin, Tugba; Akaltan, Funda; Sari, Saziye|
|Publication:||Case Reports in Dentistry|
|Date:||Jan 1, 2017|
|Previous Article:||Calcifying Acne: An Unusual Extraoral Radiographic Finding.|
|Next Article:||Revascularization in Immature Permanent Teeth with Necrotic Pulp and Apical Pathology: Case Series.|