Quintessence International, 06/2010

Eruption disturbance of a permanent tooth is challenging to clinicians. Eruption failure of a posterior tooth causes lateral open bite that severely interrupts function. This case report describes the treatment of nonerupting permanent molars by segmental repositioning followed by orthodontic fine adjustment. Two nonerupting permanent molars at different eruption stages were repositioned with a one- or two-step single-tooth segmental osteotomy technique. Final location of the repositioned tooth-alveolar bone segment was adjusted via orthodontic means. Keywords: segmental osteotomy, tooth eruption disturbance, tooth ankylosis

The unharmonious esthetic appearance of anterior teeth can be caused by changes in tooth color, shape, and size or by traumatic dental injury. Because the fragment bonding technique can restore functionality, morphology, and especially esthetics, it should be one of the choices in the restoration of fractured anterior teeth if the fragment is available. This article describes a clinical case of bonding of fractured anterior teeth and demonstrates how an esthetic appearance can be satisfactorily restored without wear to sound structure. Keywords: dental esthetics, dental fracture, fragment bonding

Objective: To report and evaluate ultrasonic bone surgery (USBS), also known as piezosurgery, in split-crest procedures with immediate implant placement at 3 years of follow-up. Method and Materials: Sixty-one split-crest procedures were performed, and 180 implants were placed in 43 patients. Initial ridge width varied between 1.5 and 5.0 mm (mean 3.3 ± 0.7 mm). Bone density was type I (11.1%), type II (27.8%), type III (28.9%), and type IV (32.2%). The USBS device worked with a 20 to 32 kHz vibrating frequency and 90 W peak power. Results: Mean split length was 14.8 ± 10.8 mm; mean final ridge width was 6.0 ± 0.4 mm. At second-stage surgery, five of 180 implants failed to osseointegrate (2.8%), all in the maxilla. Also at second-stage surgery, the success rate of the implants placed simultaneously to the split crest performed with USBS was 97.2% overall, 95.1% in the maxilla and 100% in the mandible. No loaded implant failed during the 3-year followup; respective success rates were unchanged. Conclusions: USBS is predictable to perform split-crest procedures, without risk of bone thermonecrosis; it decreases the risk of soft tissue alteration. Bone-cutting efficiency was satisfactory with the present USBS device because of its elevated ultrasonic vibrating power, especially in soft type IV bone. Keywords: Bio-Oss, bone density, dental implants, piezosurgery, PRP, split-crest, ultrasonic bone surgery

Various options are available in clinical practice for the replacement of a single missing tooth, ranging from conventional fixed and removable dental prostheses to a single implant-supported crown. There are situations in which a semipermanent fixed dental prosthesis may be desirable, particularly for patients who have completed orthodontic treatment but are too young to embark on implant therapy. Following advances in fiberreinforcement technology, fiber-reinforced composite resin (FRC) now represents a lower-cost alternative to traditional metal-ceramic for the construction of resin-bonded prostheses. Two case reports illustrate the use of FRC prostheses as fixed semipermanent restorations. Keywords: composite resin, fiber-reinforced, fixed partial denture, fixed prosthesis, provisional

Rotary root canal instruments manufactured from nickel-titanium alloy have proved to be a valuable adjunct for root canal therapy. Over the past two decades, instrument design has been considerably modified; progress has been made in manufacturing, as well as alloy processing. Clinical procedures and ideal working parameters are still being refined as new instruments continue to be introduced to the market. This review is intended to summarize clinical and laboratory findings for several current instruments. Some guidelines and usage parameters are also detailed. Keywords: nickel-titanium, root canal anatomy, root canal preparation, shaping

Objectives: Retention of mandibular complete dentures on two or four interforaminal implants is considered the most reliable procedure in implant therapy. There are different retention elements available for all implant systems. The aim of the present study was to clinically evaluate patients with a mandibular overdenture supported by the Ankylos SynCone system (Dentsply). Method and Materials: Thirty-nine patients were treated with 156 implants. The treatment method was based on immediate loading of four interforaminal implants without the use of a bar retainer. The denture was placed on and retained by prefabricated conical crowns that were inserted into the existing denture base by direct intraoral polymerization immediately after surgery and supported by the corresponding conical primary implant abutments. Results: The cumulative implant survival rate was 98.7% (two failures), while the prosthesis survival rate was 100%. After a total observation of 30.3 months (range 12 to 60 months), all other implants presented healthy peri-implant soft tissue conditions showing low value of clinical parameters. Conclusion: This method facilitates secondary splinting of the inserted complete denture. The conical crowns concept presented here resulted in stable complete denture retention, reduced the denture base, and improved oral hygiene. Keywords: complete dentures, dental implants, edentulous mandible, immediate loading, overdentures, prefabricated telescopic restorations

Objective: To evaluate the clinical efficacy of two flowable composite resins used to restore occlusal caries lesions. Tetric Flow (Vivadent) and Esthet-X Flow (Dentsply/Caulk) are composite resins with decreased filler loading (Tetric Flow: 67% filler by weight, 43% by volume; Esthet-X Flow: 61% filler by weight, 53% by volume) and lower viscosity compared to conventional composite resins. Method and Materials: Sixty-three teeth with occlusal caries were randomly assigned to calibrated practitioners who placed occlusal restorations (32 for Esthet-X Flow; 31 for Tetric Flow). After tooth preparation and caries removal, each material was inserted. A polyvinyl impression was made of each preparation and measured to record the preparation size. Prime & Bond NT (Dentsply/Caulk) was used to bond both flowable composites, which were incrementally placed and light cured for 20 seconds. Each restoration was evaluated at baseline (1 week after restoration placement) and 3, 6, 12, and 36 months for marginal discoloration, secondary caries, anatomical form, retention, polishability, marginal adaptation, and color match. Groups were compared at 3 years and the data analyzed statistically with a .05 level of significance using generalized estimating equations, with size of restoration compared to the modified Ryge criteria. Results: Of the effects that were estimable, only color match exhibited a difference between treatment groups (P = .0467, favoring Esthet-X Flow). No other differences were observed between materials. Although no difference was observed between groups, marginal discoloration (P = .0164) and marginal adaptation (P = .0001) significantly worsened at 36 months. For polishability, a significant difference was observed at 36 months (P = .0066). No other outcomes changed significantly over time. Size of the restoration was found to be positively associated with worse outcome for color match (P = .0062 for area; P = .0439 for volume). Conclusion: Although flowable composite resins are advocated for occlusal restorations, this study suggests that they should be limited to small restorations such as preventive resin restorations having isthmus widths of one-quarter or less of intercuspal distance. Keywords: clinical, flowable composite resins, marginal adaptation, marginal discoloration, occlusal, retention

Objective: Various bleaching modalities are now offered to patients, either monitored by the dental office or self-directed, for which relative efficiency is unknown. The aim of this in vitro study was to evaluate the ability of bleaching products and protocols to lighten enamel and dentin. Method and Materials: Bovine tooth specimens of standardized thickness (2.5 ± 0.025 mm with similar dentin and enamel thickness) were prepared and stained with whole blood and hemolysate before being submitted to seven supervised or self-directed bleaching regimens: tray-based bleaching using 10% (Opalescence, Ultradent; Nite White, Discus Dental) or light-activated 30% (Metatray, Metatray) carbamide peroxide (CP); 6% (Zoom, Discus Dental) or 9% (TresWhite, Ultradent) hydrogen peroxide (HP); strips (Whitening Strips, Oral B-Rembrandt); and paint-on gel (Paint on Plus, Ivoclar Vivadent) containing 8.1% and 6% HP, respectively. Colorimetric measurements were performed on each specimen side, according to the CIE L*a*b* system, before and after staining, as well as after 5, 10, and the recommended number of bleaching applications. Results: Color change after recommended number of applications (ΔEr) varied from 15.72 (Metatray) to 29.67 (Nite White) at enamel and 14.91 (Paint on Plus) to 41.43 (Nite White) at dentin side; Nite White (10% CP) and TresWhite (9% HP) were more effective than Metatray (30% CP) and Paint on Plus (6% HP) after 5 or the recommended number of applications. Conclusion: In this in vitro study based on bovine teeth, tray-based systems produced the faster and better bleaching effect, regardless of the product and concentration used, at both enamel and dentin sides. Keywords: carbamide peroxide, home bleaching, hydrogen peroxide, over-the-counter bleaching products, tooth bleaching

Periodontitis is considered to be a multifactorial disease. Studies have indicated that part of the clinical variability in periodontitis may be explained by genetic factors. Genes can affect the immunoinflammatory host response to bacterial challenge in the periodontal tissues by means of an overproduction of proinflammatory cytokines, such as interleukin-1 (IL-1). IL-1 plays an important role in the pathogenesis of periodontitis, through its involvement in the regulation of the host's inflammatory response and bone resorption. Therefore, the genes that encode for IL-1 production have recently received most attention as potential predictors of periodontal disease progression. Hence, the relationship between IL-1 genotype and periodontal disease has been investigated by a number of studies. This review article aimed to determine whether IL-1 could be regarded as a genetic marker for periodontitis by reviewing data concerning susceptibility, clinical parameters, and treatment strategies in relation to the IL-1 genotype. The review concluded that there is currently limited evidence to implicate a specific IL-1 genotype as a risk factor for chronic periodontitis in white populations. However, there is limited evidence that genetic variation in the IL-1B polymorphism could be a risk factor for aggressive periodontitis. Keywords: immunoinflammatory host response, interleukin-1, genotype, periodontitis, susceptibility

Objective: Maternal periodontitis has been suggested as an important risk factor for preterm low birth weight. The aim of the present observational study was to assess whether full-mouth therapy of periodontitis in pregnant women reduces the risk of preterm low birth weight. Method and Materials: From April 2006 to April 2007, 302 pregnant women who were at less than 22 weeks of gestation were invited to attend a periodontal examination. Consent for periodontal screening was given by 62 mothers; 54 of them met criteria. Consent for periodontal treatment was provided by 12 patients (group 1), whereas 14 patients declined therapy (group 2). No periodontal therapy was indicated in 28 patients (group 3). Nonsurgical treatment was performed in group 1 as full-mouth disinfection between 22 and 30 weeks of gestation. Periodontal reevaluation was performed 4 to 6 weeks later. As primary outcome, the gestational age at the end of pregnancy was assessed in all groups. Secondary outcomes were birth weight and growth restriction. Results: Periodontitis treatment improved periodontal measures (P = .001) in this rather small collective. However, there were no statistically significant differences between treatment group 1 and group 2 in the gestational age, birth weight, or growth restrictions. There were also no statistically significant differences compared to group 3. Conclusions: In consideration to the limited number of patients, full-mouth therapy in pregnant women can improve periodontitis but does not significantly alter the gestational age at birth or birth weight. Therefore, new studies are needed in this field especially with respect to the genetic disposition of mothers to chronic or aggressive periodontal inflammation response. Keywords: gestational age at birth, maternal, nonsurgical periodontal therapy, periodontitis, preterm low-birth-weight infants

Objective: To determine the impact of periodontal disease on quality of life using the Oral Health Impact Profile (OHIP) 14, simplified version. Method and Materials: A cross-sectional study was conducted involving a convenience sample of 401 patients of both sexes aged 19 to 71 years. After diagnoses of periodontal condition, the patients voluntarily completed a form to collect the OHIP-14, as well as socioeconomic and demographic data. Results: Chronic periodontitis was the most prevalent, affecting 227 patients (56.7%). With regard to the impact of periodontal disease on quality of life, functional limitation was the predominant item, affecting 91.5% of the sample. The patients with aggressive periodontitis achieved the highest impact scores. The highest scores on the OHIP-14 index were those of patients with a diagnosis of chronic or aggressive periodontitis. OHIP-14 scores were associated with sex, age, and income (P .001). Conclusion: Functional limitation was the most affected dimension, and impact was significantly associated with age, income, and a diagnosis of periodontal disease. Keywords: gingivitis, impact, oral health, periodontal disease, periodontitis, quality of life

Objective: To assess in vitro the shear bond strength of a nanohybrid composite resin bonded with three adhesive systems to enamel surfaces prepared with acid and Er,Cr:YSGG laser etching. Method and Materials: Sixty extracted caries- and restoration-free human maxillary central incisors were used. The teeth were sectioned 2 mm below the cementoenamel junction. The crowns were embedded in autopolymerizing acrylic resin with the labial surfaces facing up. The labial surfaces were prepared with 0.5-mm reduction to receive composite veneers. Thirty specimens were etched with Er,Cr:YSGG laser. This group was also divided into three subgroups, and the following three bonding systems were then applied on the laser groups and the other three unlased groups: (1) 37% phosphoric acid etch + Bond 1 primer/adhesive (Pentron); (2) Nano-bond self-etch primer (Pentron) + Nano-bond adhesive (Pentron); and (3) all-in-one adhesive-single dose (Futurabond NR, Voco). All of the groups were restored with a nanohybrid composite resin (Smile, Pentron). Shear bond strength was measured with a Zwick universal test device with a knife-edge loading head. The data were analyzed with two-factor ANOVA. Results: There were no significant differences in shear bond strength between self-etch primer + adhesive and all-in-one adhesive systems for nonetched and laser-etched enamel groups (P > .05). However, bond strength values for the laser-etched + Bond 1 primer/adhesive group (48.00 ± 13.86 MPa) were significantly higher than the 37% phosphoric acid + Bond 1 primer/adhesive group (38.95 ± 20.07 MPa) (P .05). Conclusion: The Er,Cr:YSGG laser-powered hydrokinetic system etched the enamel surface more effectively than 37% phosphoric acid for subsequent attachment of composite material. Keywords: enamel etching, Er, Cr:YSGG laser, shear bond strength