International Journal of Periodontics & Restorative Dentistry, 01/2018

Interest has recently developed in the purposeful retention of root fragments with their periodontal apparatus to support bone and soft tissue at immediate implant sites in the esthetic zone. This methodology is designed to avoid bone grafting, connective tissue grafts, and the use of membranes and may have short-term benefits in terms of tissue preservation. However, it is not completely without longterm risks. At times, implants may be unintentionally placed into edentulous sites where root fragments remain. This report presents two cases of long-term failure postloading associated with unintentionally retained root fragments. Histologic evaluation evidenced retained root fragments in close association with dental implants and the surrounding bone. Scanning electron microscopic evaluation revealed that the failed implant surfaces were infiltrated by bacterial deposits and calculus. Clinicians should exercise caution when placing dental implants in sites with retained root fragments, as long-term risks may be associated with this therapy.

Immediate implant placement is performed less frequently in molar extraction sockets than in single root sockets. This is mainly due to the tripodal anatomical configuration of molar roots, which is perceived as complex and therefore unsuitable. The mechanical burden of molar sites, combined with much larger socket dimensions, make it amenable to the use of ultrawide-diameter dental implants. This article describes a practical, sequenced technique that can be used predictably for immediate implant placement in maxillary and mandibular first molar sockets, using a dry skull model for clarification. This detailed description is based on the experience of more than 580 clinical cases over a 10-year period.

The aim of this study was to evaluate the short- (1 year) and longer-term (3 years) effectiveness of a surgical procedure combining coronally advanced flap (CAF) with site-specific application of connective tissue graft (CTG) in the treatment of multiple gingival recessions (MGR). A total of 60 periodontally healthy subjects with esthetic complaints due to excessive tooth length presenting multiple (at least three) Miller Class I and II gingival recession defects (≥ 1 mm) affecting adjacent teeth in the maxilla and mandible were enrolled in the study. All recessions were treated with CAF. The CTG was applied in gingival defects with a baseline keratinized tissue height (KTH) 1 mm or with KTH between 1 and 2 mm and gingival thickness 1 mm. Complete root coverage (CRC) was obtained in 98.5% (263 of 267 recessions) and in 94.7% (256 of 267 recessions) of the sites at the 1- and 3-year follow-up visits, respectively. No statistically significant differences were found at 1 and 3 years in terms of CRC between sites with or without CTG and between sites belonging to the maxilla or mandible. A greater increase in KTH at 3 years was demonstrated in sites treated with CTG. This was ascribed to the tendency of the mucogingival line to regain its genetically determined position and not to graft exposure. The present study demonstrated that the proposed surgical technique combining CAF with site-specific application of CTG was an effective treatment modality for the management of MGR, obtaining 93% CRC in the CAF-treated sites and 100% CRC in the sites treated with CAF + CTG at 3 years.

Vertical ridge augmentation in the posterior mandible is a technique-sensitive procedure that requires adequate anatomical knowledge and precise surgical skills to minimize the risk of complications. One of the most important but also challenging aspects of the surgical technique is proper flap management to allow for passive flap closure and reduce the chances of postoperative complications affecting deep anatomical spaces. This article presents a detailed description of a novel lingual flap advancement technique and its validation via a split-mouth, comparative study using a cadaver model. A total of 12 fresh cadaver heads presenting bilateral posterior mandibular edentulism were selected. Sides were randomized to receive a classic lingual flap release technique (control) or the modified technique presented here, which involves the intentional preservation of the mylohyoid muscle attachment to the mandible. Vertical flap release was measured at three different zones using standard forces. The mean difference between the test and control group in zones I (retromolar pad area), II (middle area), and III (premolar area) was 8.273 ± 1.794 mm (standard error of the mean [SEM] = 0.5409 mm), 10.09 ± 2.948 mm (SEM = 0.8889 mm), and 10.273 ± 2.936 mm (SEM = 0.8851 mm), respectively, reaching very strong statistical significance (P .0001) in all three zones.

The aim of this study was to evaluate buccal-lingual bone remodeling after fresh socket implant placement and immediate loading at 3 years of follow-up by cone beam computed tomography (CBCT). A total of 96 implants were placed in fresh sockets in anterior maxillary regions and immediately loaded. The sockets were divided into two groups related to buccal bone thickness: group A, with a buccal bone thickness > 1 mm, and group B, with a thickness ≤ 1 mm. The CBCT scans were performed before tooth extractions and 3 years after implant placement, and measurements were assessed. At 3 years, all fresh sockets in both groups presented considerable buccal-palatal crestal reduction. In both groups, statistically significant (P .05) bone loss was found between time points. There was no statistically significant difference in bone reduction between groups at 3 years of follow-up. Nevertheless, sockets with vertical axis presented more bone volume reduction than those with axis parallel to buccal bone after implant placement.

The present case series aimed to explore the potential clinical benefits of the application of dental pulp stem cells (DPSCs) in the regenerative treatment of deep intrabony defects. A total of 11 isolated intrabony defects in 11 chronic periodontitis patients were accessed with a minimally invasive flap and filled with DPSCs loaded on a collagen sponge. A tooth requiring extraction for impaction or malpositioning was used as an autologous source for DPSCs. An average clinical attachment level gain of 4.7 ± 1.5 mm associated with a residual mean probing depth (PD) of 3.2 ± 0.9 mm and remarkable stability of the gingival margin was observed at 1 year. Complete pocket closure (PD ≤ 3 mm) was achieved in 63.6% of the experimental sites. Clinical outcomes were supported by the radiographic analysis showing a bone fill of 3.6 ± 1.9 mm.

Maintenance or reconstruction of interproximal papilla for a successful dental implant restoration can be challenging. To date, the results from various surgical and prosthetic techniques to maintain or regenerate papilla adjacent to dental implants have been unpredictable. To maintain the quality of the soft tissue around an implant, the blood supply must be preserved and formation of scar tissue must be minimized during surgery. Therefore, incision design is vital to producing an esthetic and successful dental implant restoration. In this study, specific incision designs and soft tissue management techniques were used to preserve or create interproximal papilla around single or adjacent implants.

The purpose of this study was to test whether prosthetic treatment with different intraradicular posts influences the color of the buccal gingiva at teeth restored with zirconia crowns. A total of 31 patients in need of a full-coverage single crown at an endodontically treated premolar, canine, or incisor in the maxilla or the mandible were included. The patients were randomly assigned to receive composite build-ups using titanium (Ti), zirconia (Zi), or glass-fiber (Gf) posts or a build-up using no post at all (NP). All the teeth were restored with veneered zirconia single crowns. Spectrophotometric color measurements of the buccal gingiva were taken at the test teeth prior to and after the prosthetic treatment, and at the contralateral vital control tooth. The differences of the color components ΔL, Δa, and Δb and the total color difference ΔE between the test tooth prior to and after treatment and between the test and control tooth were calculated. The color differences were analyzed to determine whether they varied from 0 and 3.7, the threshold for detection by the human eye. Analysis of variance was performed to compare ΔE, ΔL, Δa, and Δb in the four post groups. The prosthetic treatment induced a significant color change ΔE in all the groups (Ti: ΔE1 = 6.4 ± 1.9; Zi: 7.1 ± 2.0; Gf: 6.2 ± 3.5; NP: 6.6 ± 3.5). There was no significant difference between Ti, Zi, Gf, and NP with respect to ΔE, ΔL, Δa, and Δb. Gingival color ΔE differed significantly between the test and control teeth before (Ti: ΔE = 6.8 ± 3.0; Zi: 9.0 ± 3.5; Gf: 5.7 ± 2.1; NP: 8.2 ± 2.8) and after prosthetic treatment (Ti: ΔE = 6.0 ± 2.8; Zi: 7.1 ± 2.9; Gf: 7.2 ± 3.0; NP: 6.9 ± 2.6). The use of different intraradicular posts (titanium, zirconia, glass fiber) or no post at all did not influence the color of the buccal gingiva at teeth restored with zirconia crowns. There was a significant gingival color difference between endodontically treated teeth and vital control teeth, both before and after prosthetic treatment.

The aim of this study was to compare the amount of radiographic horizontal buccal bone thickness (BBT) at implant dehiscence defects grafted with the sandwich bone augmentation (SBA) and modified sandwich bone augmentation (MSBA) techniques. Compared to the SBA technique, the MSBA approach involved an additional outer layer of deproteinized bovine bone mineral (DBBM) to maintain the space for bone regeneration for longer periods. A total of 19 patients, each with a buccal implant dehiscence defect, were recruited. The control group was treated with SBA technique (n = 10), while the test group was treated with MSBA technique. Cone beam computed tomography (CBCT) scans, taken at three time points (before and immediately after implant surgery, and 6 months post-treatment) were used to assess the BBT at the implant platform (−1.8 mm), the rough-smooth junction (0 mm), and 2, 4, 6, 8, and 10 mm apical to the rough-smooth junction. At 6 months postsurgery, the mean BBT in control and test groups was 1.69 ± 0.38 mm and 2.55 ± 0.21 mm, respectively. Mean BBT was significantly greater in the test group at 2, 4, 6, and 8 mm apical to the rough-smooth junction. There was no statistical difference in the mean BBT at the implant platform, the roughsmooth junction, and 10 mm apical to the rough-smooth junction between the two groups (P > .05). Within the limitations of this study, it was concluded that the additional layer of DBBM enhanced BBT along the implant, except at the smooth collar.

This prospective case series enrolled consecutively qualifying patients that required immediate dental implant placement in large, uncontained, fresh molar extraction sites using recombinant human bone morphogentic protein-2/ absorbable collagen sponge (rhBMP-2/ACS) combined with mineralized bone allograft. A total of 11 patients with 15 extraction sites missing bony walls were enrolled for treatment in this prospective case series. The clinical and radiographic effectiveness of rhBMP-2/ACS combined with mineralized bone allograft supported healing of immediately placed implants. Implants were uncovered at 4 to 6 months and were clinically and radiographically evaluated for ridge preservation and implant integration. All extraction sites exhibited ridge preservation and implant integration 1 year following restoration.

This study proposed a surgical technique that solves three-dimensional conditions of extreme bone atrophy. A total of 278 surgeries with transcrestal sinus lift and fresh frozen allogenous bone blocks were performed. A total of 1,024 implants were placed. After 60 months of observation, 969 implants were considered grade I (successful), 24 grade II (satisfactory survival), and 8 grade III (compromised survival). The cumulative success and survival rates, respectively, were 94.6% and 97.7%. This innovative procedure is very effective in selected cases. Fresh-frozen human bone allografts have been shown to be a reliable biomaterial to increase bone volume with simultaneous dental implant placement.

A total of 68 extraction sockets were grafted with anorganic bovine bone mineral and covered by dense polytetrafluoroethylene membrane. Quantitative analysis of three-dimensional microcomputed tomography imaging of core samples retrieved after a mean of 21.0 ± 14.2 weeks revealed 40.1% bone volume fraction (bone volume [BV]/total volume [TV]) and 12% residual graft. Evidence of de novo bone formation was observed in the form of discrete islands of newly formed bone in direct apposition to graft particles, separated from parent bone. Anterior sockets exhibited a significantly higher percentage of residual graft compared to premolar sockets (P = .05). The BV/TV and percentage of residual graft correlated well with histomorphometric analysis of the same sites, but not with implant outcomes.

This study was conducted to evaluate the accuracy of implants placed using two different guided implant surgery materials: thermoplastic versus three-dimensionally (3D) printed. A cone beam computed tomography (CBCT) scan previously obtained and selected for single-tooth implant replacement was converted into a Digital Imaging and Communications in Medicine (DICOM) file. All models were planned and exported for printing using BlueSkyBio Plan Software with the DICOM files. A total of 20 3D-printed mandibular quadrant jaws replicating the CBCT were printed by Right Choice Milling, as was the control model to accept the control implant. Previously, 10 thermoplastic and 10 3D-printed surgical guides had been made by the same lab technician at Right Choice Milling. One Nobel Biocare implant with a trilobe connection was placed per guide and replica jaw model pair. Implants were placed using the thermoplastic and 3D-printed surgical guides, representing the two test groups, following the Nobel Biocare guided surgical protocol. A total of 21 CBCT scans were then taken, one for the control implant and one for each test implant. The CBCT volume was converted to a DICOM file and transferred to Invivo5 software version 5.4 (Anatomage). The DICOM file of each test implant was superimposed over the DICOM file of the control. The deviation of the head of the implant, the deviation of the apex of the implant, and the angle of deviation were evaluated from measurements on the superimposition of the control and test implants. Mann-Whitney U test was used to test the null hypotheses at α = .05 and a confidence interval of 95%. Descriptive statistics were used for the average ± standard deviation. The implants placed with the thermoplastic surgical guides showed an average of 3.40 degrees of angular deviation compared to 2.36 degrees for implants placed with the 3D-printed surgical guides (P = .143). The implants placed with the thermoplastic surgical guides showed an average of 1.33 mm of deviation at the head of the implant compared to 0.51 mm for implants placed with the 3D-printed surgical guides (P 0.001). The implants placed with the thermoplastic surgical guides showed an average of 1.6 mm of deviation at the apex of the implant compared to 0.76 mm for implants placed with the 3D-printed surgical guides (P .001). There was no significant difference in the angular deviations of implants placed with thermoplastic surgical guides compared to those placed with the 3D-printed surgical guide. However, the locations of the implant head and implant apex were significantly more accurate for the implants placed with the 3D-printed surgical guides compared to those placed with the thermoplastic surgical guides.

Dental therapy of traumatically ankylosed maxillary anterior teeth with an additional slight root resorption represents a great challenge for the restorative team and requires intensive planning and communication between patient, dentist, orthodontist, periodontist, and dental technician. The inhibition of vertical growth often makes dental intervention indispensable. Porcelain laminate veneers have been successfully used for more than two decades, mainly on anterior teeth, and was the minimally invasive treatment option for the present case report. Preprosthetic planning with a digital approach of the width-length ratio and the red-white esthetics were important prerequisites for a satisfactory treatment result. The treatment goal was clarified using a wax-up and a corresponding template for intraoral verification with a mock-up. The template also served as a preparation guide. Despite all risk factors, including the endodontic treatment, the 3-mm intruded position, and the slight root resorption, the patient and the restorative team decided to restore the situation with two feldspathic-ceramic veneers to provide an esthetic, time-saving, nonsurgical process for the patient.

The success of dental implants depends mainly on osseointegration and gingival sealing. Therefore, early attachment and spreading of epithelial cells might be critical for a positive outcome. Research in dental implant materials has primarily focused on surface roughness, defined by the average roughness (Ra) index, as it promotes the process of osseointegration. This study explored its influence on soft tissue attachment by looking mainly at adhesion, proliferation, and spreading of primary human cells belonging to the epithelial lineage. Characterized human gingival keratinocytes, gingival and epithelial progenitor cells were seeded on machined (S1; Ra = 0.3 to 0.6 μm), Ti-Unite (S2; Ra = 1.2 μm), and SLA (S3; Ra = 2 μm) implants. Cell adhesion with early proliferation and spreading were evaluated by combining a biochemical vitality test with imaging analyses. Findings showed that adhesion was significantly higher on S1 (36% ± 2%) and S2 (44% ± 7%) than on S3 (23% ± 6%), while early proliferation was slightly improved on S1. The resulting data, obtained through an innovative and easily reproducible in vitro method, suggest that implant surface roughness affects epithelial cell adhesion and proliferation.

Pigmentation on gingiva can be physiologic or pathologic. Gingival pigmentation is present from birth in certain individuals. However, sudden occurrence of pigmentation suggests some systemic association. In the present case, a patient was referred by a physician for biopsy of the tissue along with gingival depigmentation. The depigmentation procedure was performed in both arches, and the biopsy specimen was sent for histopathologic examination. This case highlights the importance of biopsy of gingival pigmentation with a history of sudden occurrence. A biopsy is warranted to distinguish pathologic pigmentation from physiologic.

The aim of this retrospective case control study was to compare a porcine collagen matrix (Mucograft Seal, Geistlich) with a free gingival punch graft with respect to size, invagination, and color of resulting soft tissue scar formation. Following definition of inclusion and exclusion criteria, 22 patients were retrospectively included in this study. The patients were divided into two groups. In group A, the extraction socket was filled with bovine bone mineral (Bio-Oss, Geistlich) and covered with a free gingival punch graft. In group B, the extraction socket was filled with bovine bone mineral (Bio-Oss) and covered with porcine collagen matrix. After final prosthetic reconstruction (18 implant-retained crowns and 4 fixed partial dentures), two independent examiners evaluated the size, invagination, and color of the soft tissue scar using a modified scar-evaluation scale originally developed for dermal wounds (lower values correspond to less scarring). Patient satisfaction was recorded using a questionnaire. Patient records were screened for frequency and costs of scar removal treatment. The average scar score for groups A and B was 1.33 and 4.3, respectively, revealing significantly less scarring in group B (P = .000295). Frequency and costs of scar removal treatment were statistically significantly higher in Group A (P = .000234). Patient satisfaction was not statistically significantly different between the treatment groups (P = .711 for group A and P = .809 for group B. The results suggest that alveolar ridge preservation using bovine bone mineral and porcine collagen matrix leads to less scar tissue formation when compared with bovine bone mineral and free gingival punch grafts from the palate.

A 59-year-old woman was referred for specialist treatment due to peri-implantitis affecting four implants in the anterior maxilla. On presentation, probing depths were up to 12 mm with bleeding on probing/suppuration and extensive peri-implant bone loss. There was a history of treated chronic periodontitis. Nonsurgical management was followed by regenerative peri-implant surgery. Peri-implant probing depths reduced to a maximum of 5 mm and remained stable throughout the 5-year follow-up period. Cone beam computed tomography at 2 years postoperatively confirmed the presence of regenerated peri-implant tissue and integration with the pre-existing peri-implant bone.

Given the popularity of dental implants, determining their prognosis is an integral component of dental practice. An accurate prognosis is crucial to development of an appropriate treatment plan and may require alterations as overall status or the status of implants or natural teeth change. The importance of an established set of factors for determining implant prognosis would be highlighted in dentistpatient communication and in interdisciplinary collaboration. The main objective of the proposed prognostication system is short- and long-term success of dental implants. The aim of this study was to review evidence-based prognostic factors including surgical, peri-implant, prosthetic, and overall considerations in implant dentistry and to propose a new prognostication system. A blind survey was taken by 67 prosthodontists, periodontists, and oral surgeons at three dental schools to assess the importance of each consideration based on clinical experience and available evidence. The results supported incorporation of the comprehensive review of evidence-based prognostic factors into the proposed dynamic system for dental implant prognostication.