Quintessence International, 04/2009

A case of a 31-year-old female with aggressive periodontitis over 14 years is presented. From 1993 to 2000, no periodontal therapy occurred; disease development and progression could be reconstructed upon radiographic findings. In 2000, full-mouth disinfection therapy and antibiotic therapy was performed, as well as regenerative surgical treatments. Seven years after surgical treatment, stable periodontal conditions and clear bone regeneration in the surgical areas was evident. Parole chiave: aggressive periodontitis, disease progression, full-mouth disinfection therapy, long-term outcome, regeneration, supportive therapy

Treatment of the entire root canal system is essential for the success of root canal treatment. Thus, it is necessary for the clinician to know the root canal anatomy of the human dentition and its variations. This case report describes a patient with double palatal roots on the maxillary right second molar. Meanwhile, her maxillary left second molar had, asymmetrically, only 1 palatal root. Though the possibility of 2 palatal root canals in the maxillary second molars is scarce, it should be taken into account during endodontic treatment to guarantee successful treatments. Parole chiave: double palatal roots, maxillary second molar, root canal anatomy

Bisphosphonate holiday has been suggested as a treatment modality for oral bisphosphonate- related osteonecrosis; however, there is debate that it can undermine beneficial effects of bisphosphonate therapy. A case successfully treated after bisphosphonate holiday is presented. Parole chiave: bisphosphonate, CTX, osteonecrosis, osteoporosis

Objective: To evaluate the in vivo potential of xylitol to reduce plaque acidogenicity in comparison to sorbitol. Method and Materials: After completing a questionnaire on general health, smoking, diet, and oral hygiene habits, 61 dentate adults refrained from oral hygiene for 3 days before the clinical baseline examination, which included decayed, missing, and filled teeth (DMFT) index, mutans streptococci and lactobacilli counts, and plaque acidogenicity (cH) index after a sucrose rinse. Then the participants were randomly allocated to consume either sorbitol or xylitol lozenges (5 pieces/day, 2 g each) for 4 weeks and were asked to refrain from oral hygiene for the 3 days prior to the final examination (cH, area pH 7, bacterial counts). Results: The variation of acidogenicity in different individuals was considerable at baseline (range: 0.2 to 446.6 min*µmol/L) with a mean value of 37.9 ± 58.9 min*µmol/L for the sorbitol group and 60.6 ± 87.6 min*µmol/L for the xylitol group. At the end of the study, the reduction in the xylitol group (42.9 ± 80.6 min*µmol/L) was statistically significantly higher than in the sorbitol group (6.0 ± 69.4 min*µmol/L, P = .034), which was also confirmed in an additional analysis excluding 2 participants with extreme values (reduction for xylitol: 29.5 ± 36.9 min*µmol/L; sorbitol: 1.7 ± 57.0 min*µmol/L; P = .019). Statistically significant differences were also found for the area below pH 7 (reduction for xylitol: 10.8 min pH; sorbitol, 0.2 min pH; P = .0025). Conclusion: The regular consumption of xylitol lozenges modifies dental plaque, resulting in a marked reduction in the plaque acidogenicity, which could not be detected using sorbitol lozenges. Therefore, xylitol could have an additional benefit in caries prevention. Parole chiave: acidogenicity, caries, cH index, plaque, prevention, sorbitol, xylitol

Objective: To evaluate, in vitro, dentin caries inhibition ability of a composite restoration with glass-ionomer liners in an open-sandwich configuration. Method and Materials: Rectangular dentin cavities (n = 5) were restored with a composite and glass-ionomer liner in an open-sandwich configuration where the liner was applied up to the cavity margin. Liners used were 3 resin-modified glass-ionomers (Vitrebond, 3M ESPE; Vitrebond Plus, 3M ESPE; Fuji Lining LC Paste Pak, GC) and a conventional glass-ionomer (Ketac Bond, 3M ESPE). The control group was a composite restoration (Filtek Z250, 3M ESPE) without a liner. Specimens were immersed in lactic acid gel for 3 weeks to create a demineralized lesion before being subjected to microradiographic analysis. The width of the area where the demineralization was completely inhibited at the restoration interface was measured. The total mineral loss (ΔZ) was determined at 0.25 and 1.0 mm from the cavity margin. Results: An inhibition zone was observed at the interface of all open-sandwich restorations but not in Filtek Z250. (ΔZ at 0.25 mm of all the open-sandwich restorations was significantly less than that of Filtek Z250 (analysis of variance, Scheffe's S, P .05). At 1.0 mm, only the open-sandwich restorations in Vitrebond and Vitrebond Plus groups had significantly less (ΔZ than Filtek Z250. Conclusion: Under an in vitro demineralization challenge, glass-ionomer liners in an open-sandwich restoration exhibited pronounced inhibition zones at the dentin margin and lowered the amount of mineral loss in the vicinity of 0.25 mm from the restoration interface. Parole chiave: demineralization, dentin, glass-ionomer liner, open-sandwich restoration

Objective: To evaluate the outcomes of published studies involving lingual nerve (LN) and inferior alveolar nerve (IAN) microsurgery and reviewing differences in sensory recovery and timing to repair for both groups. Method and Materials: A total of 29 patient charts referred to the principal investigator were reviewed (15 IAN and 14 LN). Age, gender, mechanism of injury, and time from injury to surgical repair were assessed. Two-point discrimination and tactile detection threshold (via von Frey monofilaments) were the utilized measured variables because both are quantifiable and repeatable data points. Results: There was a predominance of female patients (10 IAN, 12 LN), and the mean age of the patients in the IAN group (37.40 ± 9.61 years) was significantly higher than in the LN group (28.86 ± 7.99 years). The time from injury to microsurgery was longer in the LN group (234.10 ± 166.13 days) than the IAN group (137.80 ± 83.80 days). Four patients from the IAN group and 7 from the LN group were operated on more than 6 months after the injury. Of the 15 patients who underwent IAN microsurgery, 1 patient had no change in either von Frey or 2-point discrimination results after the procedure, and 2 patients had no changes in only von Frey results. For the 14 patients undergoing LN repair, 1 patient demonstrated no change in the 2-point discrimination test and 1 patient had a reduced postoperative von Frey result compared to the preoperative measurement. Conclusion: Patients undergoing LN and IAN microsurgery benefit from trigeminal nerve microsurgery. No statistically significant differences overall were observed when comparing the outcomes of LN and IAN microsurgery. Patients undergoing trigeminal nerve microsurgery for LN and IAN injuries 6 months after injury derived less sensory recovery; however, significant improvement was still observed, warranting consideration for microsurgery in those patients who might present later for initial surgical consultation. Parole chiave: inferior alveolar nerve, lingual nerve, microsurgery, trigeminal nerve microsurgery

The contour of the interdental tissues, as well as the color and texture of the keratinized tissues, are essential elements of anterior esthetics. Tissue loss in the interproximal regions, with related esthetic concerns, phonetic difficulties, and food impaction, can occur for a variety of reasons, including treatment of periodontal diseases. In periodontal surgical procedures, the soft tissues require elevation and resection to gain access to the root surfaces and osseous supporting structures. Compromised esthetics in the anterior region of the mouth could be a serious consequence of periodontal surgical procedures. Several articles have been devoted to flap designs and surgical techniques to maintain full papillary form and preserve the soft tissues during surgical access. Unfortunately, very little evidence of long-term results is available. The aims of the present article are to report a 22-year follow-up case of surgical interdental papilla preservation, discuss the anatomic variables that conditioned the outcome, and review and compare existing surgical techniques for maintaining the interproximal soft tissues. Parole chiave: anterior esthetics, interdental papilla, papilla, papilla preservation, periodontal surgery

Objectives: Implant-supported overdentures have become the treatment of choice in restoring complete edentulism, but the number of implants required and type of connectors to assure retention and stability are still controversial. The aim of this study was to evaluate the effect of connector type and implant number and location on the retention and stability of implant-supported overdentures by measuring retentive forces during vertical and 2 types of rotational dislodgment. Method and Materials: Two model designs were selected based on the number and location of the inserted implants: In a first setup, 2 implants were placed in the canine regions; in a second setup, 2 implants were placed in the canine regions and 2 in the premolar regions. Three types of connector were used in each model: magnets, balls, and locators; 10 resin bases were fabricated and 3 hooks fixed at tripodal locations for chain testing. Vertical dislodging forces and 2 aspects (oblique and posterior rotational dislodging forces) of stability were tested. Results: Two-way analysis of variance showed significant differences in retention among the 3 connectors in the 2 models, with the lowest values obtained with the magnet group (mean [SD]: 2.15 N [0.09]) and highest values with the locator group (31.30 N [0.12]). Posterior rotational dislodging forces showed higher values than vertical or lateral forces in both models; 4-implant models required higher dislodging forces than did 2-implant models. Conclusion: Locator connectors provide significantly higher retention and stability of implant-supported overdentures, followed by ball connectors and then magnets. The 2-implant design offers less retention and stability than the 4-implant model. Number of implants and type of connector significantly affected retention and stability of implant-supported overdentures. Parole chiave: ball, implant, locators, magnet, overdenture, retention, stability

Objective: Nonsteroidal anti-inflammatory drugs inhibit platelet aggregation and increase bleeding time; however, they are required to control pain and swelling following dental surgery. The objective of this study was to evaluate possible changes on blood coagulation tests by using ketoprofen and diclofenac potassium after removal of mandibular third molars. Method and Materials: Fifty-one subjects between 16 and 30 years old, with no history of gastrointestinal disorders or allergy to anti-inflammatory components, were randomly assigned to 2 groups: 27 patients received 50 mg of ketoprofen, and 24 patients received 25 mg of diclofenac potassium. Subjects started the oral medication 2 hours before surgery and continued taking it every 8 hours for 5 days. Blood samples were collected preoperatively and on the final day of the drug regime to evaluate prothrombin time, activated partial thromboplastin time, clot retraction, and platelet count. Results: Student t test for matched pairs did not show a significant difference between pre- and posttreatment variables for both antiinflammatory drugs. Conclusion: These results suggest that the safety of ketoprofen and diclofenac potassium is comparable to their anticoagulation effect. Parole chiave: blood-coagulation tests, nonsteroidal anti-inflammatory agents, third molar, tooth extraction

Objectives: The microgap at the tooth-restoration interface is inevitable and may allow bacterial penetration that could lead to failure. The purpose of this in vitro study was to assess the antibacterial potential of 4 flowable composite restorative materials. Method and Materials: The antibacterial potential of Aeliteflo (Bisco), Filtek Flow (3M ESPE), Tetric Flow (Ivoclar Vivadent), and Dyract Flow (Dentsply) was tested against Streptococcus mutans. Agar diffusion test (ADT) and direct contact test (DCT) were the methods used. For ADT, wells were punched in S mutans-inoculated plates. The materials were placed in the wells and polymerized. Inhibition zones were measured after 48 hours' incubation at 37°C. In the DCT, 8 samples of each tested material were placed on the side walls of wells in a 96-microtiter plate and polymerized. A suspension of S mutans was placed on the surface of each sample. Bacterial growth was monitored by optical density changes at 650 nm every 30 minutes for 16 hours. The experiment was repeated after the samples were aged in phosphate-buffered saline for 1 and 7 days. Results: In both tests, only Dyract Flow showed inhibition of S mutans growth. Except for Dyract Flow samples, aged samples did not statistically differ in S mutans inhibition when compared to their 1-hour control counterparts. Dyract Flow samples lost their S mutans inhibitory potential after 24 hours. Conclusion: The flowable composites tested do not possess effective long-term antibacterial ability. Parole chiave: antibacterial, direct contact test, flowable compomer, flowable composite resins

Objectives: This double-blind study examined the bleaching effectiveness of two 30% carbamide peroxide bleaching gels: one with 5% potassium nitrate (treatment A) and one without (treatment B). The treatment time was reduced for this pilot study to one hour per day for 10 days to determine whether the higher concentration would whiten teeth and to ascertain the tooth sensitivity and gingival effects of the 30% solution. Method and Materials: Forty subjects were selected with an initial tooth shade corresponding to Bioform shade guide B65 or darker. After obtaining consent, subjects were randomly divided into two groups (n = 20). Custom-fabricated bleaching trays were made for each subject. Trays did not extend onto the gingiva. Each subject was instructed in the placement and wear of the tray and bleach and supplied with one of the two bleaching gels. Subjects had 10 hours of treatment time with the bleaching gel. Photographs and shades (using a standardized Bioform shade guide) were taken at baseline and at final recall to determine bleaching effectiveness. Tooth sensitivity was measured at baseline and final recall by applying a pellet saturated with skin refrigerant to the tooth for 2 seconds. The sensitivity was recorded on a scale ranging from 1 to 10. Gingival index was also measured at baseline and at final recall. Data was analyzed with Wilcoxon rank-sum and Wilcoxon signed rank tests. Results: No significant differences were found for changes in color, tooth sensitivity, and gingival condition between the two bleaching gels (P = .899, P = .375, and P = .056, respectively). Within each group, bleaching gel A and B significantly whitened teeth (P .0001 for both groups). There were no significant changes in tooth sensitivity and gingival condition for gel A (P = .057 and .063, respectively) or gel B (P = .911 and .510, respectively). Conclusion: Thirty percent carbamide bleaching gels effectively whiten teeth without causing a significant increase in tooth sensitivity or changes in gingival condition. Potassium nitrate has little effect in sensitivity when treatment time is short. Parole chiave: carbamide peroxide, gingiva, potassium nitrate, tooth sensitivity, tooth whitening

Objective: To investigate the cervical microleakage in Class II cavities restored with Sonicsys approx ceramic inserts and four resin-based materials. Method and Materials: Forty noncarious and crack-free mandibular third molars were used. These teeth were randomly assigned to four groups each containing 10 teeth. No control group was created. On each tooth, one mesial boxlike cavity was prepared using the active head Sonicsys approx no. 3. The cervical margin of each cavity was in enamel about 1 mm coronal to the cementoenamel junction. According to manufacturer's instructions, the prepared cavities were restored using a Sonicsys approx ceramic inserts no.3 and four resin-based materials as follows: group 1, Tetric Flow; group 2, Admira Flow; group 3, Nexus 2; group 4, X-Flow. After finishing and polishing, all specimens were stored in distilled water for 7 days at 37°C, thermocycled 1,000 cycles between 5° and 55°C, and stored for 24 hours in basic fuchsine 2%. All specimens were then embedded in clear acrylic resin and sectioned along a mesial-distal plane through the middle of the cervical margin. The cervical areas of the resulting sections were examined using an optical microscope to assess the dye penetration. The registered scores were analyzed using Kruskal-Wallis and Mann-Whitney U tests. Results: Microleakage was detected in each experimental group. Kruskal-Wallis test revealed statistically significant differences among groups (P = .009, a = .01). The Mann-Whitney U test showed significant differences between Admira Flow group and Tetric Flow (P = .011, a = .05), Nexus 2 (P = .001, a = .01), and X-Flow (P = .004, a = .01), respectively. Conclusion: Within the limitations of this study, the extent of microleakage in the cervical area (enamel) of Class II cavities restored with Sonicsys approx ceramic inserts depends on the material used for luting. The highest leakage occurred when Admira flow was used. Parole chiave: cervical microleakage, resin-based materials, Sonicsys ceramic inserts