Evaluation of the peri-implant tissues in the esthetic zone with prefabricated titanium or zirconia abutments: A randomized controlled clinical trial with a minimum follow-up of 7 years.

STATEMENT OF PROBLEM: Long-term clinical studies are lacking on the influence of the type of abutment, titanium or zirconia, on peri-implant tissues. PURPOSE: The purpose of this randomized clinical trial was to evaluate peri-implant tissues with titanium or zirconia abutments. MATERIAL AND METHODS: A total of 26 single-tooth implant-supported prostheses in 14 participants were analyzed. They received either a titanium abutment with a metal-ceramic crown (TAG) or a zirconia abutment with a ceramic crown (ZAG). Data were collected immediately, at 5 months, and at a minimum of 7 years after crown delivery. The success rate, plaque and bleeding indexes, bleeding on probing, white and pink esthetic scores, and the relationships of the gingival phenotype with the pink esthetic score were analyzed. Statistical analyses were conducted with the t test for paired and independent data (α=.05). RESULTS: The mean follow-up time was 95.2 ±2.6 months, showing an implant success rate of 96.7%. No statistically significant differences were found between TAG and ZAG among the time intervals evaluated for plaque or bleeding indexes (P>.05). A statistically significant difference was found for peri-implant probing depths in the mid-buccal sites between the groups at all the time intervals evaluated (TAG, P=.008; ZAG, P=.021): TAG showed an increase between 5 months (3.65 ±0.93 mm) and over 7 years (4.47 ±1.32 mm); and ZAG showed a reduction (5 months=5.22 ±1.71 mm; over 7 years=4.25 ±1.28 mm) in values. For the pink (PES) and white esthetic score (WES), ZAG (PES: immediately=6.33 ±1.41; 5 months=7.44 ±1.81; over 7 years=8.25 ±1.03; WES: immediately=7.67 ±1.50; over 7 years=8.38 ±0.74) showed higher mean values than TAG (PES: immediately=5.94 ±2.35; 5 months=6.53 ±2.15; over 7 years=7.44 ±1.81; WES: immediately=7.00 ±1.17; over 7 years=8.35 ±1.27) (P<.05). Statistically significant differences were found for gingival phenotype and for PES in TAG (P=.031), and the participants with thick phenotype showed higher PES in the 3 time intervals studied. CONCLUSIONS: Zirconia abutments exhibited better results than titanium abutments in terms of the peri-implant tissues. Moreover, in those with a thin phenotype, zirconia provided improved gingival esthetics.

Doxycycline Release of Dental Implants With Nanotube Surface, Coated With Poly Lactic-Co-Glycolic Acid for Extended pH-controlled Drug Delivery.

When dental implants become infected, the progression of the disease is rapid. Commercially available dental implant surfaces can be easily contaminated, resulting in rapid progression of peri-mucositis and peri-implantitis. The aim of this study was to evaluate, in vitro, the pattern of doxycycline release from by dental implants with titanium nanotube surface (DINS) at different pHs to examine novel drug loading and chemical coating techniques. Nine DINS were loaded with doxycycline and subsequently coated with polylactic-co-glycolic acid (PLGA). High-performance liquid chromatography (HPLC) was used to measure the amounts of released doxycycline in a 30-day period. Cytotoxicity of the DINS was evaluated by an assay using 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT). The results showed that the experimental DINS coated with doxycycline and PLGA showed a mean drug release during the experimental period for the groups: pH 7.4 (8.39 µg/mL), pH 6.4 (8.63 µg/mL). The pH 5.4 (15.18 µl/mL) doxycycline release from DINS was faster at pH 5.4 than those at pHs 6.4 and 7.4 (P = .0031 and .0034, respectively). This new surface treatment of dental implants with titanium nanotubes and subsequent drug loading demonstrated biocompatibility and sustained doxycycline release over a 30-day period. Additional studies are needed in order to adopt a stable drug release at neutral pH environment while warranting a constant drug release in an acidic pH environment.

Mechanical Complications Related to the Retention Screws of Prefabricated Metal Abutments With Different Angulations: A Retrospective Study With 916 Implants.

OBJECTIVES: The present retrospective study assessed the clinical performance of abutment screws from prefabricated metal abutments and compared technical complication rates between straight and angled abutments. MATERIALS AND METHODS: Dental charts were selected for patients with dental implant rehabilitations delivered between 1998 and 2012. Abutment angulation, prosthetic screw type, and presence of complications that occurred during the selected time period were collected. Technical complications registered included abutment screw loosening and/or fractures detected during clinical and radiographic examinations. The chi-square test was used for statistical analysis. RESULTS: Abutment angulations were divided into 2 groups: G1) prefabricated straight abutments and G2) prefabricated angled conical mini UCLA-type abutments. A total of 916 implants (799 straight and 117 angled conical mini UCLA-type abutments) were evaluated. G1 showed 91.1% had absence of failures, which were clinically defined as any screw loosening or fracture; and 8.9% reported some type of technical complication. G2 showed 92.3% and 7.7%, with and without technical complications, respectively. CONCLUSIONS: No significant differences were observed between abutment angulation and technical complications.

Optimizing Anterior Implant Esthetics With a Vascularized Interpositional Periosteal Connective Tissue Graft for Ridge Augmentation: A Case Report.

Achieving excellence in anterior rehabilitations requires close cooperation between the periodontist and the prosthodontist. Many techniques can be used to restore the lost alveolar hard and soft tissues. The more severe the peri-implant defect, the higher the challenge and lower the predictability of the procedure. The present case consists of Seibert Class III with malaligned implants in the esthetic zone resolved with a cost-modified treatment plan to reestablish esthetics in the anterior maxilla using a rotated palatal flap. The vascularized interpositional periosteal connective tissue graft was effective in augmenting the soft tissue in the esthetic zone and remained stable over a 2-year period. Additional long-term clinical studies are necessary to support these results.

Evaluation of Effectiveness of Cement Removal From Implant-Retained Crowns Using a Proposed "Circular Crisscross" Flossing Technique.

Extruded cement during dental implant crown cementation may cause peri-implant diseases if not removed adequately. The purpose of this study was to evaluate the efficiency of removal of cement after cementation of implant crowns using an experimental circular crisscross flossing technique (CCFT) flossing technique, compared to the conventional "C"-shape flossing technique (CSFT). Twenty-four patients rendered 29 experimental and 29 control crowns. Prefabricated abutments were secured to the implant such that the margins were at least 1 mm subgingivally. The abutments were scanned using computer-aided design/computer-aided manufacturing technology and Emax crowns were fabricated in duplicates. Each crown was cemented individually and excess cement was removed using the CSFT and the CCFT techniques. After completion of cementation was completed, the screw access holes were accessed and the crown was unscrewed along with the abutment. The samples were disinfected using 70% ethanol for 10 minutes. Crowns were divided into 4 parts using a marker to facilitate measurement data collection. Vertical and horizontal measurements were made for extruded cement for each control and experimental groups by means of a digital microscope. One-hundred and seventeen measurements were made for each group. Mann-Whitney test was applied to verify statistical significance between the groups. The CCFT showed a highly statistically significant result (104.8 ± 13.66, P < .0001) for cement removal compared with the CSFT (291.8 ± 21.96, P < .0001). The vertical measurements of the extruded cement showed a median of 231.1 µm (IQR = 112.79-398.39) and 43.62 µm (IQR = 0-180.21) for the control and the experimental flossing techniques, respectively. The horizontal measurements of the extruded cement showed a median of 987.1 µm (IQR = 476.7-1,933.58) and 139.2 µm (IQR = 0-858.28) for the control and the experimental flossing techniques, respectively. The CCFT showed highly statistically significant less cement after implant crowns cementation when compared with the CSFT.

The Value of Occlusion in Dentistry: A Clinical Report Showing the Correction of an Anterior Reverse Articulation with Selective Occlusal Adjustment.

The subject of occlusion has been deemphasized by academia over the last 30 years. This marginalization in turn has negatively impacted recent graduates who are largely unfamiliar with the use of occlusal adjustment by selective reshaping as a treatment modality. Use of proper occlusal therapy enables clinicians to more effectively help patients recover from parafunctional wear of the anterior and posterior teeth. In addition, familiarity with this field enhances the correction of progressive posterior and anterior reverse articulations. This article aims to highlight the importance of occlusal principles in treatment planning. In addition, we illustrate the benefits of occlusal adjustment by using a conservative technique, selective reshaping, as an option to correct anterior reverse articulation in a 20-year-old patient. The knowledge of occlusal principles enhances diagnosis of malocclusion in the development of a treatment plan. When properly employed, the technique of occlusal adjustment by selective reshaping may be used to correct an adaptive anterior reverse articulation with a high degree of predictability for select patients.

Zirconia Abutment Supporting All Ceramic Crowns in the Esthetic Zone: Interim Results of a Prospective Study.

AIM: This prospective study evaluated peri-implant tissues around all-ceramic crowns fabricated using CAD/CAM technology. MATERIAL AND METHODS: Twenty-five patients received pre-fabricated zirconia implant abutments with CAD/CAM zirconia copings in the esthetic zone. Implants were evaluated at baseline, and at 3 and 6 months in function. RESULTS: Radiographic analyzes showed stable bone crest around the implants. Esthetics were more favorable as time lapsed (p > 0.05). Bleeding Index was constant in all time intervals. Plaque index reduced from 3 to 6 months. CONCLUSION: The all-ceramic CAD/CAM crowns were clinically, radiographically and esthetically stable during the study period.

Step-by-Step Resin Bonding of Ceramic Veneers in the Anterior Maxilla: A Case Report.

Applying the biomimetic principles, maximum preservation of the sound tooth structure may be achieved by means of adhesive restorations. Due to bonding, it is possible to conduct minimally invasive esthetic procedures with laminate veneers assuring a high mechanical resistance of the tooth/restoration bond. A clinical case of adhesive restorations is presented using the bonding protocol respecting the diversity of each product's commercial brands and manufacturer's recommendations.

Occlusal rehabilitation of pseudo-class III patient.

To treat a patient with anterior crossbite, the clinician should first assess if it is a genuine class III or a pseudo-class III malocclusion. Cephalometric analysis is important; however, registering a patient's centric relation (CR) is simple, quick, and costless and can play a decisive role in a differential diagnosis for this type of patient profile. This clinical report depicts a patient clinically diagnosed as class III. After mandible manipulation in CR, it was noted that the patient in question was a pseudo-class III. The treatment was based on the pseudo-class III diagnosis. Therefore, the patient was rehabilitated by occlusal adjustments and conventional and implant-supported prostheses and without the need for invasive orthognathic surgery.

Prevalence of Peri-implant Diseases: Analyses of Associated Factors.

UNLABELLED: AIM. Identify the relationship between specific factors (age, sex, smoking, time of prosthesis in function, implant location, and width of peri-implant keratinized mucosa) and peri-implant diseases in patients from the Center of Research and Continuing Education in Implant Dentistry (CEPID) at the Federal University of Santa Catarina (UFSC), Brazil. MATERIALS AND METHODS: A cross-sectional study was conducted in 193 patients that had received 725 external-hexed cylindrical implants supporting functional prosthesis for at least 1 year (range from 1-9 years). Clinical examination included probing depths, bleeding on probing and/or suppuration. Radiographic exam was conducted to measure peri-implant bone levels. RESULTS: There was no statistically significance in the association between prevalence of peri-implant diseases and age, sex, time with prostheses in function and implant location variables independently. There was a statistically significant association between the independent variables of smoking and the width of keratinized peri-implant mucosa less than 2mm, and the presence of peri-implant diseases. When all the categories were evaluated together in relation with the peri-implant diseases, the prostheses in function for 5 years and more had association with presence of both, peri-implant mucositis an peri-implantitis. Peri-implantitis prevalence was higher for males with the prostheses in use for 5 years or more. Peri-implant mucositis was more associated with the participants over 57 years of age, with systemic disease and with the prostheses in function for more than 5 years. CONCLUSIONS: Smoking habits and the width of peri-implant keratinized mucosa as independent variables were associated with the prevalence of peri-implant diseases.

An alternative approach for augmenting the anterior maxilla using autogenous free gingival bone graft for implant retained prosthesis.

Numerous factors may keep surgeons from placing implants in the anterior maxilla in order to avoid suboptimal restorative outcomes. This paper describes a technique of an autogenous-free gingival-bone block graft, which allows bone and gingival augmentation and a primary seal to be achieved simultaneously. Additionally, it describes a technique for achieving primary soft tissue closure of maxillary extraction sockets using a rotated pedicle palatal connective tissue flap.

The Ability of Dental Specialists to Distinguish Lateral Incisor Metal-Free From Porcelain-Fused-to-Metal Implant Supported Crowns.

The objective of this study was to evaluate the ability of dental specialists to distinguish lateral incisor metal-free from porcelain-fused-to-metal implant supported crowns in the anterior region. Five single-tooth implants in the maxillary lateral incisor region were restored with two types of implant-supported crowns (porcelain-fused-to-metal and metal-free). Photographs were presented to 20 evaluators. The evaluators had to answer whether the crown was: metal-free, porcelain-fused-to-metal or they could not tell the difference. The results showed that groups 1 (all participants), 3 (Restorative & Prosthodontic specialists), 4 (graduated 10 years) and 5 (graduated > 10 years) failed to respond correctly (P > 0.05) to which type of crown was presented to them. Group 2 (Periodontology & Implantology specialists) showed an accuracy rate of 35.6% (P = 0.009), in relation to metal-free crowns, 5.6 which is below the random index. The authors concluded that the evaluators from the 5 groups studied were unable to significantly distinguish which type of crown was used in the 10 presented situations.

Esthetic Crown Lengthening and Minimally Invasive Laminate Veneers to Resolve Altered Passive Eruption.

Background: Altered passive eruption (APE) in the esthetic zone can be an esthetic concern to the patient. To restore adequate crown dimensions, crown lengthening procedures may be necessary. Methods: The present case is a report of a patient with an unsatisfied smile due to a complaint of short clinical crowns. The periodontal diagnosis was APE and deviated maxillary anterior midline. A mock-up was made to assist the provider in evaluating the patient's esthetic concerns and acceptance of the proposed treatment plan. Results: Esthetic crown lengthening and ultrathin ceramic laminate veneers were used to treat an APE type I subdivision B, resulting in a gingival display reduction and in final PES/WES scores of 10. Conclusion: The use of periodontal plastic surgery in conjunction with ultrathin ceramic laminate veneers was mandatory to restore an unesthetic smile. The proposed treatment reduced the gingival display significantly and increased the crown height to length proportions reaching an esthetic smile and patient satisfaction.

Histological Evaluation of Alveolar Ridge Preservation Using Different Bone Grafts: Clinical Study Analysis Part II.

To compare histologically the percentage of bone formation 12-20 weeks after ridge augmentation using 2 different techniques. Tooth loss is associated with 3-dimensional bone remodeling and ridge atrophy. Ridge preservation procedures can prevent alveolar bone volume loss. Different techniques and materials are used to preserve the alveolar ridge. Computer-generated randomization software was used to assign 2 ridge preservation techniques for 11 extraction sites. In group I, type I bovine Achilles tendon collagen plugs with bioactive resorbable calcium apatite crystals (CPCAC) were placed, and in group II, cortico-cancellous bone chips (CCBC) mix and an expanded polytetrafluoroethylene (ePTFE) barrier membrane were placed. The histomorphometric studies were performed using a computer-based image analysis system (ImageJ 1.4, National Institute of Health, Bethesda, Md) to calculate the pixel area of bone tissue and the remaining bone graft material. The histomorphometric data were analyzed using a Student t test to compare the measurements between the 2 experimental groups. This parametric statistical test was employed to determine if there were any statistically significant differences in the quantitative histological parameters between the groups. The sockets that received CPCAC showed a lower (31.89%) percentage of native bone surface area compared with the CCBC group (43.87%). However, the difference was not statistically significant (P < .05). In addition, the CPCAC group showed evidence of foreign-body reaction. The CCBC graft covered with an ePTFE barrier may induce more bone formation with minimal inflammation in an extraction socket compared with a collagen plug with calcium apatite crystals. In addition, histological analysis of the CPCAC graft showed evidence of foreign-body reaction, which indicates a negative clinical impact.

Bacterial cellulose matrix and acellular dermal matrix seeded with fibroblasts grown in platelet-rich plasma supplemented medium, compared to free gingival grafts: a randomized animal study.

PURPOSE: Mucogingival defects (MGDs), such as dental root recessions, decreased vestibular depth, and absence of keratinized tissues, are commonly seen in dental clinics. MGDs may result in functional, aesthetic, and hygienic concerns. In these situations, autogenous soft tissue grafts are considered the gold-standard treatment. This study compares the healing process of free gingival grafts (FGGs) to bacterial cellulose matrix (BCM) and human acellular dermal matrix (ADM) seeded with fibroblasts from culture supplemented with platelet-rich plasma in a rat model. METHODS: Surgical defects were made in rats, which received the following treatments in a randomized manner: group I, negative control (defect creation only); group II, positive control (FGG); group III, BCM; group IV, BCM + fibroblasts; group V, ADM; and group VI, ADM + fibroblasts. Clinical, histological, and immunological analyses were performed 15 days after grafting. Clinical examinations recorded epithelium regularity and the presence of ulcers, erythema, and/or edema. RESULTS: The histological analysis revealed the degree of reepithelization, width, regularity, and presence of keratin. The Fisher exact statistical test was applied to the results (P<0.05). No groups showed ulcers except for group I. All groups had regular epithelium without erythema and without edema. Histologically, all groups exhibited regular epithelium with keratinization, and myofibroblasts were present in the connective tissue. The groups that received engineered grafts showed similar clinical and histological results to the FGG group. CONCLUSIONS: Within the limitations of this study, it was concluded that BCM and ADM can be used as cell scaffolds, with ADM yielding the best results. This study supports the use of this technical protocol in humans.

A technique to create an interocclusal bite registration using in situ implant healing abutments.

Obtaining an accurate interocclusal record which relates the upper and lower jaws to one another is critical in the laboratory production of dental restorations. This may be particularly challenging when the configuration of missing teeth dictate that such records are dependent on the remaining mucosal tissues for support. This article presents a practical and time saving method of using implant healing abutments, located within an edentulous distal extension space, to serve as vertical stops for an interocclusal record.

Relationship between smoking and bleeding on probing.

The objective of this study was to assess and compare bone loss (BL) around the dental implant platform as well as the presence of bacterial plaque (PBP), bleeding on probing (BOP), and periodontal probing depths (PD) of teeth and dental implants of smokers and nonsmokers. Three hundred forty-seven teeth and 98 implants of 20 randomly selected patients were assessed (12 smokers and 8 nonsmokers). The specimens were divided into 4 groups according to the site probed. Group 1 included smoker implant sites, group 2 included smoker tooth sites, group 3 included nonsmoker implant sites, and group 4 included nonsmoker tooth sites. The presence/absence of visible bacterial plaque, presence/absence of BOP, PD ≤ 3 mm or >3 mm, and BL around the dental implant platform were the data assessed. The PBP and BL showed statistical significance between smokers and nonsmokers. Bleeding on probing and PD ≤ 3 mm showed statistical significance between groups 1, 3, and 4. Comparing sites with BOP and PD > 3 mm, there was no statistical significance except for group 1, which did not present sites with these characteristics. Comparing sites with BOP and PD ≤ 3 mm, there was statistical significance between group 2 and groups 3 and 4. When comparing the prevalence of sites without BOP and PD > 3 mm, there was statistical significance between groups 1, 3, and 4. Smoking promotes a greater BL around the dental implant platform and results in vasoconstriction of the peri-implant and periodontal tissues.

Dental implant rehabilitation of a patient with down syndrome: a case report.

Implant-supported rehabilitations show higher patient satisfaction when compared with conventional prostheses. Systemic conditions, however, can affect treatment planning of dental implant supported rehabilitations. The oral structures that are commonly affected in patients with Down syndrome include the tongue (macroglossia), teeth (number and shape), and poor quality alveolar and jaw bones (osteoporotic-like). This clinical case presents an interdisciplinary team approach aimed at achieving functional, phonetic, and esthetic outcomes in a patient with Down syndrome.

"Crawling Attachment" during Periodontally Accelerated Osteogenic Orthodontics Procedure.

The present clinical case reports an increased zone of keratinized gingiva that was generated following surgical excision of the gingiva during periodontally accelerated osteogenic orthodontics. The present case consists of angle Class I with mal-aligned teeth and impacted #11. The patient was evaluated up to 2 years and 1 month (2.1) showing a stable increased zone of keratinized tissue. Possible causes for this event are discussed in this case report. Additional long-term clinical studies are necessary to support these results.

Allogeneic Bone Application in Association with Platelet-Rich Plasma for Alveolar Bone Grafting of Cleft Palate Defects.

AIM: The aim of this study is to compare allogeneic bone grafts associated with platelet-rich plasma (ALBGs-PRP) to autogenous bone grafts (ATBGs) for alveolar reconstructions in patients with cleft lip and palate (CLP). MATERIALS AND METHODS: The Maxillofacial Surgery Service of the Comprehensive Care Center for CLP (CCCLP) in Curitiba (Paraná, Brazil). PATIENTS: Thirty out of 46 patients with 8-12 years of age and pre- or trans-foramen unilateral clefts were operated by the same surgeon. Groups were selected randomly after coin-toss for the first surgery to be ALBG-PRP. INTERVENTIONS: Pre- and post-surgery cleft defect severity was registered by a score system using superimposed digitalized peri-apical radiographs. The hypothesis indicated ABG-PRP to be similar to the ABG was proved. RESULTS: There was no statistically significant difference (P < 0.05) in bone augmentation for the ABG-PRP group (79.88%) when compared to the ABG group (79.9%). CONCLUSION: ABG-PRP is indicated as a successful treatment modality to reduce the need for additional donor sites and reduce morbidity and hospital stay.