A 60-year-old female patient was referred to the Department of Periodontology with the chief complaint of mobility of the maxillary anterior teeth. The patient was diagnosed with generalized severe chronic periodontitis and gingival recession due to bone loss in the central and lateral incisors, as well as canines. In addition, lateral incisors were rotated in place and were in an overlapped position on the central incisors, which caused crowding in the anterior maxillary segment. The same problem was previously addressed in her mandibular incisor with implant-supported FPD, but the periodontal prognosis was not acceptable, and the patient was unsatisfied with the esthetic and functional results.
Supra-gingival scaling and sub-gingival scaling were performed using Ultrasonic Piezo Scaler (DTE, Wuhan, China) and Gracey curette (Hu-Friedy Mfg. Co., LLC, Chicago, IL, USA), respectively. The periodontal indices were measured using a color-coded Michigan Williams probe (Premium Instruments, Ronkonkoma, NY, USA) after 4 weeks. They include gingival recession, pocket depth, and tooth mobility, as are shown and defined in Table 1. As the maxillary right and lateral incisors had grade II and III mobility with probing depths of 7 and 8 mm and more than 50% bone loss, respectively, with a hopeless periodontal prognosis, their extraction was recommended (Figures 1(a) and 1(b)). All the possible treatment modalities for the replacement of the lateral incisors and their costs, benefits, and prognosis were explained to the patient. After obtaining informed written consent, we chose and initiated the treatment plan with FRC bridge using natural tooth pontics.
The maxillary right and left lateral incisors were extracted under local anesthesia (1 cartridge of xylopen 2%; lidocaine 12 mg/epinephrine 12.5 mug/ml, Exir, Borujerd, Iran), and the extraction was performed atraumatically with no need of suture. The extracted teeth were scaled and polished thoroughly to remove all the deposits on them and kept in distilled water at the temperature of 4 C until the restorative procedure (Figure 2(a)).
After three weeks, the healing of the extraction socket was re-evaluated, and the stable periodontal status was affirmed (Figures 1(c) and 1(d)). An impression of the maxillary arch with c-silicon material (Speedex, Coltene, Langenau, Germany) and the study model was made in order to adjust the length and proximal contours of pontics and correct the crowding in the anterior maxillary segment. The approximate cutting location on the root of the lateral incisors was marked while holding the teeth near their previous location on the study model. The root section was initiated using a cylindrical diamond bur in a way that the remained tooth portion consisted of an anatomical crown, in addition to a part of the root due to mimicking the gingival recession (Figure 2(b)). The pontics seem shorter than the natural teeth due to the root section. However, the remained tooth structure represents the clinical crown of pontics in harmony with the appearance of adjacent teeth.
The opening of the root canal was enlarged in the tissue side of the pontics with round diamond bur (Jota, Ruthi, Switzerland; Figure 2(c)). The root canal space was instrumented (K-file, Dentsply-Maillefer, Tulsa, OK, USA) and then debrided with sodium hypochlorite (NaOCl) 2.5% (Sigma-Aldrich, St. Louis, MO, USA) and remained in place for 10 minutes followed by irrigation with normal saline (Figure 2(d)). The pontics were kept in distilled water at 4 C for one week in order to prevent the detrimental effect of NaOCl on the bond strength.
Then, the root canal space was washed with distilled water, dried using paper points, and filled with Vertise  Flow as a Self-Adhering Flowable Composite (Kerr Dental, Kloten, Switzerland); it was cured (BlueLEX, GT 1200, New Taipei City, Taiwan) at the light intensity of 1200 mW/cm2 and wavelength of 470 nm for 40 seconds from each aspect of the pontics (Figure 2(e)). Then, the proximal contours of the pontics were stripped using cylindrical diamond bur (Jota) in order to achieve the appropriate intra-arch position and correct the crowding in the anterior maxillary segment. There was no need for occlusal plan correction before the placement of RBB due to the corrected alignment of pontics in the arch. The tissue side of the pontics was formed in a sanitary ovate shape in a way that it could be cleansable by dental floss. Proximal contacts and soft tissue contact of the pontics were assessed intraorally, and the final adjustment was done to ensure there would be cleansable embrasures and optimized soft tissue contact of the pontics to establish the physiological massage of the edentulous ridge soft tissue. The tissue edentulous as the adjusted proximal contour of the pontics was then finished and polished using the OptiDisk Finishing and Polishing system (Kerr Dental, Brea, CA, USA) in 4 sequences.
On the middle third of the palatal surfaces of pontics and abutments (from the middle of the right canine to the middle part of the left one), preparation of 2 mm incisogingival width and 1.5 mm depth to preserve the enamel substrate was performed using a round diamond bur number 1 (Figure 2(f)). The prepared palatal surfaces were etched (Scotchbond  Etchant, 3M ESPE, Washington, DC, USA) for 20 seconds, then rinsed, and dried (Figure 3(a)). Total etch adhesive (Adper Single Bond 2, 3M ESPE) was applied and light cured according to the manufacturer's instructions. The pre-impregnated resin fiber strip (Interlig, Angelus, Londrina, Brazil) was adopted in prepared surfaces, covered by flowable composite resin (Universal flow, Tokuyama, Encinitas, CA, USA), and then light cured for 20 seconds on each tooth. The pontics were fixed in place with Universal flow (Tokuyama) in proximal contact areas of pontics and light cured for 20 seconds. Universal composite resin (Estelite Sigma Quick, Tokuyama) was applied and cured in some areas as needed for providing smooth contour (Figure 3(b)).
The occlusion was evaluated in centric position, protrusive, and lateral movements, and adjusted to remove heavy occlusion force in the pontics in the middle third portion where fiber was placed (Figures 3(c) and 3(d)). Then, the palatal surfaces were finished with football shape medium grit diamond bur and polished with impregnated silicon rubber points. The chronological order of all the clinical procedures is shown in Table 2.
The RBB was re-evaluated after 6 months in the point of esthetic, occlusion, soft tissue contact of the pontics, and periodontal status of abutments and restored part of retainers and pontics (Figures 3(e), 3(f), 3(g) and 3(h)). There was no sign of microleakage in the palatal surface of the retainers and pontics. Pontics showed no color change and were completely in accordance with adjacent retainers in appearance, color, and optical properties. The patient was satisfied with her smile and appreciated. Periodontal examination showed a stable condition without any mobility in abutments, and no edema, recession, or proliferation was detected in the soft tissue (Table 1). Follow-up evaluation after 1 year was still satisfactory without apparent complication (Figures 4(a), 4(b), 4(c) and 4(d)).