Quintessence International, 03/2015

Objective: The aim of this prospective clinical study was to evaluate the clinical performance of lithium disilicate allceramic crowns for a period from 12 to 156 months. Method and Materials: One hundred and twenty five lithium disilicate all-ceramic crowns were placed in 35 patients between 2001 and 2007. One patient who received four all-ceramic crowns was excluded from the study. The remaining 34 patients received 121 all-ceramic crowns and were recalled. Ninety-eight anterior and 23 posterior crowns were inserted. All crowns were applied on vital teeth except for 11 crowns which were placed on endodontically treated teeth. Follow-up appointments were performed 6 months after insertion, then annually. Replacement of a restoration was defined as failure. Marginal integrity, marginal discoloration, secondary caries, sensitivity, color match, and ceramic surface were evaluated following modified California Dental Association/Ryge criteria. The survival rate of the crowns was determined using Kaplan- Meier statistical analysis and log-rank test (P = .05). Results: Ten crowns were fractured. The cumulative survival rate according to Kaplan-Meier was 87.1% after mean 104.6 months (range 12 to 156 months). Location (anterior vs posterior) of all-ceramic crown did not significantly affect the survival rate according to log-rank test (P = .89). Endodontically treated teeth without post-and-core restorations exhibited a higher failure rate after all-ceramic crown application according to log-rank test (P .001). Conclusion: In this in vivo study, lithium disilicate all-ceramic crowns exhibited a satisfactory clinical performance with an estimated survival probability of 87.1% over 104.6 months and they can be used clinically in the anterior and posterior region. Restoring endodontically treated teeth with post-and-core restorations should be considered before all-ceramic crown application. Keywords: adhesive luting, all-ceramic crowns, clinical study

Objectives: The aim of this study is to report on the treatment of mandibular Class II furcation defects with enamel matrix protein derivative (EMD) combined with a βTCP/HA (β-tricalcium phosphate/hydroxyapatite) alloplastic material. Method and Materials: Thirteen patients were selected. All patients were nonsmokers, systemically healthy, and diagnosed with chronic periodontitis; had not taken medications known to interfere with periodontal tissue health and healing; presented one Class II mandibular furcation defect with horizontal probing equal to or greater than 4 mm at buccal site. The clinical parameters evaluated were probing depth (PD), relative gingival margin position (RGMP), relative vertical clinical attachment level (RVCAL), and relative horizontal clinical attachment level (RHCAL). A paired Student t test was used to detect differences between the baseline and 6-month measurements, with the level of significance of .05. Results: After 6 months, the treatment produced a statistically significant reduction in PD and a significant gain in RVCAL and RHCAL, but no observable change in RGMP. RVCAL ranged from 13.77 (± 1.31) at baseline to 12.15 (± 1.29) after 6 months, with a mean change of −1.62 ± 1.00 mm (P .05). RHCAL ranged from 5.54 (± 0.75) to 2.92 (± 0.92), with a mean change of −2.62 ± 0.63 mm (P .05). After 6 months, 76.92% of the patients improved their diagnosis to Class I furcation defects while 23.08% remained as Class II. Conclusion: The present study has shown that positive clinical results may be expected from the combined treatment of Class II furcation defects with EMD and βTCP/HA, especially considering the gain of horizontal attachment level. Despite this result, controlled clinical studies are needed to confirm our outcomes. Keywords: Class II furcation defects, enamel matrix protein derivative, periodontal regeneration, synthetic bone substitute

Objective: Dyslipidemia, a disorder in the levels of cholesterol or lipoproteins in the plasma, is a feature of atherosclerosis, leading to cardiovascular disease. The objective of this study was to evaluate whether Tanerella forsythia and Treponema denticola are related to reduced levels of antiatherogenic high density lipoprotein (HDL). Method and Materials: In this cross-sectional study, 108 patients were invited to participate. The diagnosis of chronic periodontitis and the diagnosis of adipose tissue disorders were made based on criteria previously defined. The presence of T forsythia and T denticola was detected by polymerase chain reaction. Results: A total of 61 women and 19 men with chronic periodontitis, and 18 women and 10 men without periodontitis were studied. The serum levels of total cholesterol and low density lipoprotein were similar in both groups. Inversely, the levels of triglycerides (TG) were higher in periodontitis patients compared to subjects without periodontitis (178 mg/dL vs 165 mg/dL; P .05), and the levels of HDL were lower (44 mg/dL vs 50 mg/dL; P .05), respectively. The presence of T denticola was associated with low levels of HDL in periodontitis patients after adjustment for possible confounders (OR, 3.03; 95% CI, 1.2-7.2). Conclusion: Higher levels of TG and lower levels of HDL were associated with the presence of T denticola in chronic periodontitis. These results may suggest that the presence of T denticola could reduce the antiatherogenic potency of HDL and may increase the risk for cardiovascular disease in patients with chronic periodontitis. Keywords: atherosclerosis, cardiovascular disease, periodontitis, plasma lipids

The use of zirconia abutments for single-tooth restorations is well documented and supported by clinical studies with observational periods of up to 5 years. However, data for fixed partial dentures (FPDs) on all-ceramic abutments are lacking. Therefore, this indication cannot yet be generally recommended. Based on the available clinical studies, it can be assumed that the treatment results for anterior restorations can be improved by using all-ceramic abutments, especially in situations with a reduced thickness of the peri-implant soft tissues ( 2 mm). Zirconia abutments for single-tooth restorations can be restored with glass-ceramic crowns on a lithium-disilicate base or crowns with oxide-ceramic structures (alumina or zirconia). If the restorations are cemented adhesively, then all of the cement residues must be carefully removed. Superstructures based on zirconia ceramics can be removed to a certain degree if they are cemented temporarily or screwfixed with directly veneered abutments. However, prior to providing a general recommendation for temporary cementation or screw-fixation of all-ceramic superstructures, additional clinical data are needed. Keywords: abutment, clinical performance, esthetics, implant, zirconia

Objectives: Metal ceramic restorations continue to be widely used in dental practice, as they combine esthetics with superior mechanical properties. However, ceramic materials have the potential to fracture due to their brittle nature. The purpose of this study was to evaluate the clinical survival of fractured metal-ceramic restorations repaired with an indirect technique which uses a new "overlay" metal-ceramic crown that is luted to the existing restoration. Method and Materials: The study population consisted of 92 patients. Only patients with one or more fractured retainers of multipleunit metal-ceramic fixed partial dentures were involved in this study. In all cases there were a bulk fracture of the overlaying ceramic material and exposure of the underlying metal substructure. The remaining retainers of the fixed partial dentures were intact. The total number of fractured retainers was 106. All clinical procedures of the indirect repairs were carried out by a single investigator, according the previously published technique. The patients were examined clinically at 1, 2, 4, 6, and 8 years after placement of the new restorations. The repaired restorations were examined for debonding, fracture rate, and esthetics. Patient acceptance was also recorded. Results: Of the 92 patients re-examined, all were satisfied with the function and the esthetic appearance of their restorations. None of the repaired restorations fractured after 8 years of service, and there were no gingival margin problems of significance. Four restorations debonded during the evaluation period. The overall survival rate was 96.2% after 8 years. Conclusion: Repair methodology and materials employed in this study resulted in satisfactory longevity for metal-ceramic dental prostheses. The success rate was 96.2% after 8 years. The retention rate was very good, patient satisfaction was very encouraging, and maintenance of the esthetics was good. Keywords: clinical longevity, fracture, indirect method, metal-ceramic fixed dental prosthesis, repair

Objective: This study evaluated the efficacy of an anatomicalradiologic- surgical protocol for the extraction of erupted maxillary third molars (EMTMs). Methods and Materials: 166 EMTMs were extracted according to two different extraction techniques. Group 1 (G1, 97 teeth) was treated with the proposed protocol: multiple roots with forceps DG 117/DG 118; single roots with DG 250; tapered roots with DG 270; curved roots with Apexo 303 elevator. Group 2 (G2, 69 teeth) was treated with straight elevator and forceps DG 250 or DG 270. Extraction time and total number of complications (TNCs) were the main outcomes; TNCs were also divided in complications during the extraction (CDEs) and complications after the extraction (CAEs) as secondary outcomes. Results: Differences between G1 and G2 were detected for extraction time (146.8 vs 225.6 seconds; P .05) and for complications (G1, 13.4% vs G2, 47.8%; P .001). Multivariate analysis showed that extraction time and smoking habit were independent risk factors for TNCs (P .001); furthermore, "not applying the proposed extraction protocol" increases almost 7 times (6.86; 95% CI, 1.41-33.32; P .02) the possible onset of CAEs. Conclusion: The proposed protocol can be helpful for the general dental practitioner in planning the extraction of EMTMs, shortening the extraction time, and diminishing the complications, especially those occurring after the extraction. Keywords: complications, extraction, extraction time, maxillary third molar

A definitive diagnosis is crucial for management of any oral mucosal disease. Direct immunofluorescence (DIF) is a valuable diagnostic aid for immune-mediated blistering diseases and systemic connective tissue diseases of the skin and the mucosa. This paper gives an overview of the DIF biopsy technique for oral lesions and provides a background for the clinician to optimize the utilization of DIF biopsy. The key characteristic diagnostic findings of DIF of specific mucosal diseases are also discussed. Keywords: direct immunofluorescence, immune-mediated blistering diseases, oral vesiculobullous disease, oral biopsy technique, systemic connective tissue diseases

During the last decade an increased interest in alternative, preventive, and therapeutic strategies in dentistry has arisen. Probiotics are living microorganisms which, if administered in sufficient amounts, provide a health benefit to the host. Their precise mechanisms of action have not been identified, but they are able to interfere with the imbalance occurring in biofilm-associated infections. In other fields of medicine, mainly in gastroenterology, their usefulness is already proven. Concerning oral threats, probiotic bacteria may reduce the numbers of pathogens associated with dental caries (mutans streptococci). Clinically, results are encouraging, but further research is needed to demonstrate apparent effects of certain probiotic strains on oral health as well as their desired concentration and vehicle. The use of probiotics in prevention and treatment of caries, periodontal diseases, halitosis, and other oral diseases needs to be further investigated. Keywords: caries, periodontal disease, probiotics, tooth decay

Objective: Thin supporting tissues may cause gingival recessions and esthetic problems in the anterior area. The objectives of this study were to present a simple and reliable radiographic technique to measure thickness of alveolar bone labial to mandibular incisors, and to establish a possible correlation of bone thickness with its tissue biotype. Method and Materials: A metal strip was placed over the gingiva of the mandibular incisor axis, and a perpendicular occlusal radiograph was taken of 51 patients. Patients in routine orthodontic practice before any orthodontic treatment was started were distributed into three groups according to their periodontal biotype (A1, thin with 2 mm keratinized gingiva; A2, thin with > 2 mm; and B, thick with wide zone of keratinized gingiva), as described by Müller and Eger.1 Radiographs were scanned and thickness of gingival tissue and of bone at two levels (at the bone crest and at 3 mm below the bone crest) was measured to the nearest 0.1 mm. Measurements of soft tissue and bone thickness were compared and correlated. Results: Groups A2 and B showed a significant difference in bone thickness at the bone crest. Correlation of bone and gingival thickness was only found in gingival biotype B at 3 mm below the bone crest level only (R = 0.290; P .001). No other correlation between bone and gingival thickness was observed in any group. Conclusions: The radiographic technique proposed in this study is a simple and reliable method for calibrating the amount of buccal bone in the mandibular anterior area. It is a cheap and fast diagnostic tool that may help determine the amount of buccal bone and gingival thickness, and therefore avoid excessive radiation to patients. Groups A2 and B showed a significant difference in bone thickness at the bone crest. Although not significant, group A1 showed the lowest values of bone and gingival thickness, whereas group B showed the highest bone and gingival thickness. A clear correlation between thickness of bone and gingiva 3 mm below the cementoenamel junction was found in group B. Keywords: diagnosis, gingival recession, gingival thickness, oral hygiene