Quintessence International, 09/2010

Objective: This study investigated the effects of trauma to primary teeth, related by age at the time of injury and type of injury sustained, to the frequency and type of developmental disturbances in the permanent successor teeth in a representative population of Maltese children. Method and Materials: Thirty-two children with 67 traumatized primary teeth were examined and any developmental disturbances of the corresponding permanent teeth recorded. Results: Altogether, 52.2% of the permanent teeth exhibited developmental disturbances following trauma to their primary predecessors. The highest frequency of malformations was found following subluxation injuries. Intrusion injuries were associated with the most severe malformations. Age at the time of trauma to the primary dentition was a principal factor in the risk and severity of malformations developing in the permanent successors. Conclusion: The extent of malformation of the developing tooth germ was highly related to its developmental stage and to the severity and type of trauma sustained by the primary incisor. Keywords: dental trauma, developmental disturbances, permanent incisor, primary dentition, sequelae

A 16-year-old girl was referred for surgical-orthodontic treatment with the chief complaint of an unerupted mandibular left second molar. With the exception of this molar, the patient had a fully erupted permanent dentition. A panoramic radiograph showed a horizontally impacted mandibular left second molar beneath a mesially impacted third molar. A surgical approach was used to upright and reposition the impacted second molar. When a molar is severely impacted, surgical uprighting may provide a viable option when other treatment modalities are contraindicated. This case shows an example of successful use of a surgical approach for uprighting and repositioning an impacted molar. The impacted molar was moved into its proper position with surgical exposure, after which it showed good stability. Keywords: impaction, mandibular second molar, molar repositioning

Objectives: Owing to the overwhelming popularity of oral piercing, general practitioners should be prepared to address complications arising as a result of oral piercing and to provide patients with accurate information. The purpose of this cross-sectional study was to assess the prevalence of early and late complications associated with lip and tongue piercing in a population obtained from a nondental setting. Possible cofactors were evaluated. Method and Materials: The study cohort included 130 lip and 80 tongue piercings. Participants were asked to complete a questionnaire to determine demographic data, smoking habits, characteristics of the piercing worn (time since piercing, material-plastic or metal), postpiercing complications, and possible cofactors. Results: Prevalence of early piercing complications was 87.83%. Although there was no statistically significant difference in the overall prevalence of early postpiercing complications after lip or tongue piercing, the type of complication differed significantly according to the piercing location. Significant cofactors for early complications were oral hygiene behavior, gender, and the person who performed the piercing. The highest prevalence of late complications was found to be recurrent infections and gingival recessions. As cofactors, time since piercing and oral hygiene behavior had a significant impact on late complications. Conclusion: Early complications after oral piercing are frequent. Oral health care might be an important tool to minimize early and late postpiercing complications. Owing to the high prevalence of late complications-especially after median lip piercing-persons with oral piercing should attend regular dental checks and receive professional advice on tooth cleaning and oral hygiene. Keywords: body piercing/adverse effects, complications, gingival recession, lip, questionnaire, tongue

Multiple recession defects in the dentition of an individual are routinely encountered in clinical practice and as such present a challenge for management. Periodontal plastic surgical procedures aim to restore both gingival esthetics as well as function in these defects. This case report highlights four periodontal plastic surgical techniques (the coronally advanced flap for single and multiple recession defects, double papillae with subepithelial connective tissue graft, and envelope technique with subepithelial connective tissue graft) that have been employed for root coverage in isolated Miller Class I recession defects in a 35-year-old individual. Three of the techniques resulted in 100% root coverage in all treated sites, while the site treated with subepithelial connective graft by envelope technique resulted in 83.3% root coverage. Treatment also helped to resolve hypersensitivity and achieved satisfaction of the patient's esthetic concerns. Keywords: gingival recession, hypersensitivity, multiple recession, periodontal plastic surgery, root coverage, subepithelial connective tissue graft

Objectives: The longevity of frictional telescopic crowns (FTC) in severely reduced dentitions with 1 to 3 remaining teeth per jaw has not yet been studied prospectively and exclusively. Aims of this study were to estimate risks of telescope loss and abutment tooth loss and to determine abutment tooth mobility over time. Method and Materials: A total of 74 patients with severely reduced dentitions received 82 telescopic removable partial dentures (TRPDs) retained with 173 FTCs. Dentures were reexamined after 1 week and 3, 6, 12, 18, 24, 30, and 36 months. Tooth mobility was monitored with Periotest values. Adjuvant therapies were carried out if necessary. Survival probabilities of telescopes and abutment teeth as well as the influence of clinical factors (age, sex, jaw, vitality, opposing dentition, axis inclination, end Periotest value, crown length, crown margin quality, wearing mode, tooth types, abutment distribution, number of telescopes) were calculated with Kaplan-Meier estimators. The relative risks for telescope loss were calculated with Cox regression. Results: The survival rate was 93.9% for abutment teeth and 87.5% for telescopes. Number of telescopes, abutment distribution, vitality, and gender as factors influenced the survival rates (Kaplan-Meier). In combination with the jaw as a factor, these affected the risk for telescope loss (Cox regression). Periotest values (mean of abutment teeth per examination) decreased significantly (P .0001). Altogether, 11% of teeth fractured and 4.6% of teeth were extracted. Patients were mostly very satisfied. Conclusion: TRPDs proved to be a favorable treatment concept for severely reduced dentitions. FTCs can be considered as elements with a good benefitmaintenance relation. A general increase of abutment tooth mobility could not be verified. Keywords: abutment tooth mobility, frictional telescopic crowns, Periotest values, prospective clinical study, severely reduced dentition, survival probability

Objective: Recent studies have shown that the apical negative-pressure irrigation system EndoVac (Discus Dental) produces better disinfection and cleanliness at the apical third of root canals than current irrigation methods using positive pressure. The aim of this histologic study was to compare the EndoVac system at two different exposure times to the traditional positive-pressure irrigation technique for root canal cleaning efficacy and to measure the volume of irrigation at the apical third. Method and Materials: Fifty extracted human incisors, canines, and premolars (with one canal) were used. All teeth were stored in sterile saline and then randomly assigned to one of three experimental groups of 15 each. All teeth were cleaned and shaped at working length using Profile Series 29 (Dentsply Tulsa) to a size 6 (ISO size 36) or larger depending on the first instrument to bind at the apical third. After working length was reached with the master apical file, apical irrigation was accomplished with 6% sodium hypochlorite (NaOCl) over a predetermined time for each group as follows: group 1, EndoVac for 210 seconds; group 2, EndoVac for 150 seconds; group 3, traditional positive-pressure irrigation for 210 seconds. The amount of debris left in the canals was quantified at 1 and 3 mm from working length. Results: No statistical differences were found at 3 mm from working length. At 1 mm from working length, an overall test of association was significant when comparing across the three groups (P = .03). Conclusion: The apical negative-pressure irrigation system EndoVac has the potential to achieve significantly better root canal cleaning at the apical third of root canals and in less exposure time than required with traditional positive-pressure irrigation. Keywords: apical negative-pressure irrigation, canal preparation, exposure time, irrigation, volume

Schwannoma is a benign tumor arising from nerve-sheath Schwann cells. When it affects the mouth, the lips are rarely involved. A MEDLINE search in the English literature from 1969 to 2009 revealed only 17 documented cases of schwannomas of the lip. This report describes the unusual case of a 52-year-old man who developed a schwannoma of the lower lip. Histopathologic examination and immunohistochemical staining studies were performed. Although rare, schwannoma should be considered in the differential diagnosis of any nodule or mass in the oral mucosa. Keywords: CD-34 protein, lip, neurilemmoma, neurinoma, S-100 protein, schwannoma

Objective: To determine the formation and dissolution of calcium fluoride on the enamel surface after application of two fluoride gel-saliva mixtures. Method and Materials: From each of 80 bovine incisors, two enamel specimens were prepared and subjected to two different treatment procedures. In group 1, 80 specimens were treated with a mixture of an amine fluoride gel (1.25% F-; pH 5.2; 5 minutes) and human saliva. In group 2, 80 enamel blocks were subjected to a mixture of sodium fluoride gel (1.25% F; pH 5.5; 5 minutes) and human saliva. Subsequent to fluoride treatment, 40 specimens from each group were stored in human saliva and sterile water, respectively. Ten specimens were removed after each of 1 hour, 24 hours, 2 days, and 5 days and analyzed according to potassium hydroxide-soluble fluoride. Results: Application of amine fluoride gel resulted in a higher amount of potassium hydroxide-soluble fluoride than did sodium fluoride gel 1 hour after application. Saliva exerted an inhibitory effect according to the dissolution rate of calcium fluoride. However, after 5 days, more than 90% of the precipitated calcium fluoride was dissolved in the amine fluoride group, and almost all potassium hydroxide-soluble fluoride was lost in the sodium fluoride group. Calcium fluoride apparently dissolves rapidly, even at almost neutral pH. Conclusion: Considering the limitations of an in vitro study, it is concluded that highly concentrated fluoride gels should be applied at an adequate frequency to reestablish a calcium fluoride-like layer. Keywords: calcium fluoride, enamel, fluoride gel, saliva

Objective: The aim of this pilot study was to assess the possibility of differences in the calcium concentration of the saliva between smoker and nonsmoker patients with or without periodontitis. Method and Materials: A total of 44 women were enrolled in this study. Exclusion criteria were severe general health problems, the prescription of medication, and fewer than 16 remaining teeth. The study population comprised 24 smokers (4 periodontitis free, 16 with chronic and 4 with aggressive periodontitis; mean age 50.2 years ± 6.9) and 20 nonsmokers (10 periodontitis free, 9 with chronic and 1 with aggressive periodontitis; mean age 54.7 years ± 15.6). Clinical parameters (bone loss; plaque, gingival and calculus indices; and pocket depth) were recorded, and stimulated saliva samples were collected. The calcium concentration of each saliva sample was measured by atomic absorption spectrophotometry. Statistical analysis was performed with the MANOVA test. Results: The mean salivary calcium level in the smokers (57.76 µg/mL ± 18.8) was significantly (P .05) higher than in the nonsmokers (44.6 µg/mL ± 7.8). Periodontal examination revealed significantly greater bone loss, a deeper mean probing depth, and a higher amount of calculus (P .05) among the smokers. However, there were no statistically significant differences between the smokers and the nonsmokers as concerns the plaque and bleeding indices. Conclusions: Within their limits, the present findings seem to indicate that patients with periodontitis who smoke exhibit higher salivary calcium levels than those in nonsmokers. However, the clinical significance of these findings remains to be determined in large-scale controlled studies. Keywords: calculus, nonsmokers, oral hygiene, periodontitis, salivary calcium level, smokers

Objective: To compare the depth of cure (DoC) of a colored polyacid-modified composite resin (PAM-C) with a traditional PAM-C and a fine hybrid composite resin using different light-curing units and different radiant energies. Method and Materials: The DoC of the PAM-C Twinky Star (Voco, all shades), the PAM-C Glasiosite (Voco), and the composite resin Z100 (3M ESPE) shades A2 and A4 was determined using a penetrometer test method. The materials were cured in bulk using a halogen-based unit (Elipar Trilight, E = 18 J/cm2 and E = 32 J/cm2; 3M ESPE) and an LED curing unit (Elipar Freelight 2, E = 20 J/cm2; 3M ESPE) in split stainless steel molds. Immediately after curing, the height (mm) of the cured material was measured and taken as the DoC. Ranking of means was performed by Student-Newman-Keuls multiple comparison test, and statistically significant differences among mean values were detected with ANOVA. Results: Mean DoC for all materials and shades varied as follows: 4.705 to 8.870 mm (E = 32 J/cm2); 3.672 to 8.050 mm (E = 20 J/cm2); and 4.090 to 7.357 mm (E = 18 J/cm2). Two-way ANOVA revealed that the DoC depended significantly (P .001) on the shade of the material and the curing device. Moreover, there was a significant interaction (P .001) between the latter, indicating that the effect of the energy densities differed quantitatively among the shades. Conclusions: In this study, DoC differed significantly among the materials and the shades. Twinky Star shade blue showed the highest DoC compared to Glasiosite and Z100 shades A2 and A4. The curing device with the highest energy density exhibited the highest curing depths. Keywords: colored polyacid-modified composite resin, compomer, curing depth, light-curing unit, penetrometer

Objective: Several kinds of functional water are used in the fields of food hygiene and medicine. The purpose of this study was to evaluate both the disinfection and cytotoxic effects of functional water in comparison with commonly used root canal irrigants such as sodium hypochlorite solution and hydrogen peroxide solution. Method and Materials: Three kinds of functional water were examined: alkaline electrolysis water (AEW), strong acid electrolyzed water (SAEW), and hypochlorous acid water (HAW). The disinfection effect was studied using Enterococcus faecalis and Candida albicans with or without organic substance. Each kind of functional water was applied to samples, and the colony formation was evaluated. The cytotoxic effect was evaluated by mitogenic assay (MTT) and alkaline phosphatase (ALPase) activity in pulp cells. Results: SAEW and HAW showed microbicidal effects in the presence of organic substance, with an effect almost similar to sodium hypochlorite solution. AEW did not show any microbicidal effect. SAEW, AEW, and HAW at 10- and 1,000-times dilution did not inhibit the MTT assay and ALPase activity. The cytotoxicity of SAEW and HAW against pulp cells was mild compared to that of sodium hypochlorite solution. Conclusion: Functional water like SAEW and HAW have a good microbicidal effect under existing organic substance and are also mild to pulp cells. Keywords: cytotoxic effect, electrolyzed water, functional water, hypochlorous acid water, microbicidal effect, root canal irrigation

Objectives: To investigate the push-out bond strengths of one epoxy resin-based quartz-fiber post with four adhesive systems. Method and Materials: Forty-four single-rooted, single-canal teeth were randomly divided into four groups (n = 11): One-step (One-Step + Duo-link; Bisco), Variolink II (Excite DSC + Variolink II; Ivoclar Vivadent), Panavia F (ED primer + Panavia F; Kuraray), and RelyX (RelyX Unicem; 3M ESPE). All teeth crowns were removed, and the roots were treated with root canal therapy. Four adhesive systems were employed for bonding of one type of quartz-fiber post, strictly according to the manufacturers' instructions. Ten roots in each group were transversely sectioned into cervical, middle, and apical third slices 2 mm thick, and the bond strengths were measured with the push-out test. The other root was processed for SEM analysis. Two-way ANOVA, one-way ANOVA, and Student-Newman-Keuls test were used for statistical analysis. Results: The push-out bond strengths were 7.15 ± 3.43 MPa (RelyX), 12.48 ± 9.33 MPa (One-step), 2.96 ± 2.76 MPa (Panavia F), and 13.43 ± 6.14 MPa (Variolink II). Two-way ANOVA showed statistically significant differences among adhesive systems (P .05) and root regions (P .05). The bond strengths of One-step and Variolink II groups were statistically higher than those of RelyX and Panavia F groups. The bond strengths of the cervical region of One-step and Panavia F groups were statistically significantly higher than those of the other two regions. The SEM images showed uniform and long resin tags in One-step and Variolink II groups, whereas few or no resin tags were visible in the other two groups. Conclusion: The type of adhesive system and root region had a significant influence on the bond strengths of the adhesively luted fiber posts. Total-etching technique achieved better bond strength than did the self-etching technique. Keywords: adhesive system, bond strength, fiber post, push-out test, root dentin, self-etching, SEM observation, total etching