Clinical Report
A 45 years-old female patient presented to the clinic with the chief complaint “My front crowns are loose and they come off sometimes”. The patient reported that she had had crowns made of porcelain fused to metal placed on teeth from the maxillary right lateral incisor to the left incisor, fifteen years ago. (Fig. 1) These crowns had become loose and come off sometimes; she used to cement them back with an over-the-counter remedy from the pharmacy. The papilla between the teeth was also decreased leading to black triangles between them.
After a detailed clinical evaluation, the maxillary right lateral incisor, both central incisors and left lateral incisor were diagnosed with mobility grade II, and incisal wear was found on the on maxillary right and left canines. Radiographic evaluation showed the old crowns and metal posts on the maxillary left latera incisor, both central incisors and right lateral incisor. The patient had high esthetic demands, and showed interest in having fixed all-ceramic restorations from maxillary right canine to left canine. The patient was informed of the need to remove the old crowns in order to re-asses the clinical situation of the teeth, and agreed to the procedure.
The existing restorations of the maxillary incisors were removed, and secondary caries was found in all teeth, with a fractured core on maxillary left central incisor, and mobility grade II on all teeth. Therefore, these teeth were deemed hopeless. (Fig. 2) The patient was informed of the option of having 2 implants in order to support a fixed prosthesis from maxillary left lateral to right lateral incisors, and single restorations on maxillary right and left canines. The patient approved the plan and the treatment was initiated.
A diagnostic wax-up was performed and a milled provisional restoration was fabricated for the span between maxillary canines. The maxillary canines were prepared, and the patient was sent for tooth extractions. The maxillary central and lateral incisors were extracted and particulate cortico-cancellous allograft bone (Cortical/Cancellous Chips, AlloSource Headquarters, Centennial, CO, USA) with collagen dressing (Puracol, Collagen Wound Dressing, Medline Industries Inc, Northfield, IL, USA) and resorbable sutures (Polysyn FA, Surgical Specialties Corporation, Wyomissing, PA, USA) was placed to achieve complete socket seal. (Fig. 3) The milled provisional restoration, made of polymethyl methacrylate, was cemented with an ovate pontic shape in the extraction sites, without interfering with the sutures. The initial provisional restorations applied a very light pressure, and included a space between the soft tissue and the provisional restoration to enable the patient to clean underneath the pontic and in the connector areas. (Fig. 4)
The patient returned two weeks later. The provisional was removed, and the pontic units were built-up using self-curing acrylic resin (Jet Tooth Shade, Lang Dental, Wheeling, IL, USA) in order to establish contact under slight pressure and maintain the developed ovate soft tissue contour, while the interproximal areas between the pontic units were opened with a disc (Acrylic Temporization System, Brasseler USA Dental, Savannah, GA. USA) in order to provide space for the papilla tissue. The patient returned again 2 weeks later and same procedure was performed.
Two months later, the patient was seen again for follow-up and the same procedure was performed. The thickness of the soft tissue was measured with a periodontal probe. (Williams Color-coded single end probe, Hu-Friedy Mfg. Co., LLC. Chicago, IL, USA) Carbide and diamond football burs (Medium Football bur, Brasseler USA Dental, Savannah, GA, USA) were used to improve the architecture of the pontic sites. (Fig. 5) The provisional restoration was built-up again using acrylic resin material (Acrylic Temporization System, Brasseler USA Dental, Savannah, GA, USA) in order to match the contour provided by the football burs. Two weeks later, the provisional restoration was removed to evaluate the final contour of the soft tissue. (Fig. 6)
The soft tissue achieved the desired shape and the implant therapy was planned using implant software (SimPlant, Dentsply Sirona Implants Inc, York, PA, USA). (Fig. 7) Two implants at the sites of maxillary right lateral incisor and maxillary left central incisor were planned to support a dental prosthesis from maxillary left lateral incisor to right lateral incisor. These sites were chosen based on the condition and thickness of the bone in the incisor region. Implant surgery was performed with palatally-oriented crestal incision and bilateral sulcular incisions on the canines to reflect a full muco-periosteal flap. The incision lines for the flap were planned to avoid damaging the soft tissue line created during the preparation. Two bone-level implants of size 4.1mm (BLT RC, Straumann Group, Basel, Switzerland) were inserted. (Fig. 8) A simple interrupted suture technique (Polysyn FA, Surgical Specialties Corporation, Wyomissing, PA, USA) was used for primary soft tissue closure. (Fig. 9) The implants were not loaded, and the existing fixed provisional restoration was cemented back on to the canines. During the two months of osseointegration, the provisional restoration maintained the soft tissue architecture that has been previously obtained.
After 4 months, the pontic sites of maxillary right lateral incisor and left central incisor were hollowed with acrylic carbide burs (Acrylic Temporization System, Brasseler, Savannah, GA, USA) in order to accept the temporary cylinders (Cylinder RC, Straumann Group, Basel Switzerland) engaged with the implants. The new screw-retained provisional restoration maintained the same tissue contour and three weeks later a final impression was made. (Fig. 10) The final restorations were screw-retained porcelain fused to zirconia to replace the incisors with zirconia abutments which were fixed to the titanium bases and single porcelain fused to zirconia crowns on the canines. Final restorations were tried-in for clinical and radiographic assessment, and patient satisfaction was achieved. Final implant restoration was placed and torqued according to the manufacturer instructions, while single crowns on maxillary right and left canines were cemented (RelyX Luting 2 Cement, 3M Espe, Saint Paul, MN, USA).Occlusion was checked and adjusted as necessary. Patient was satisfied with the final outcome. (Fig. 11) A night guard was provided in order to protect the dentition and final restorations.