Influence of chemical activation of a 35% hydrogen peroxide bleaching gel on its penetration and efficacy--in vitro study

OBJECTIVES: The aim of this study was to evaluate the effects of chemical activation of hydrogen peroxide (HP) gel on colour changes and penetration through the tooth structure. METHODS: One hundred and four bovine incisors were used. One dentine (CD) disc and one enamel-dentine (ED) disc were prepared from each tooth. They were positioned over artificial pulpal chambers and the bleaching was performed with an experimental 35% HP gel. Two control and six experimental groups were prepared. In the positive control group (PC) no chemical activator was used. In the negative control group (NC) the specimens did not receive any bleaching. Each experimental group received a different chemical activator (manganese gluconate-MG; manganese chlorite-MC; ferrous sulphate-FS; ferrous chlorite-FC; and mulberries root extract-MRE). After the bleaching procedure a sample of solution was collected from the artificial pulpal chamber and the HP concentration was measured. The data were analysed using ANOVA, Tukey's, and Dunnett's tests. RESULTS: The groups MG and FS showed a significantly lower penetration of HP than the PC group. For the parameter Delta E, all the groups, with the exception of the group MRE, showed a significantly higher means in relation to the PC group in ED colour. For dentine colour, just the groups MG and FS had significant differences in relation to PC. CONCLUSIONS: The addition of MG and FS decreases the penetration of HP. The chemical activation using metal salts tested was effective in increasing the bleaching effect

Microbiological effects of four treatment approaches

GesamtdissertationZiel dieser prospektiven, einfachblinden, klinischen Studie war, die Auswirkungen von vier unterschiedlichen Behandlungsmethoden auf fünf Markerkeime der Parodontitis zu untersuchen. Darüber hinaus wurde die Patientenakzeptanz für jede Methode dokumentiert. Bei 72 Patienten mit chronischer Parodontitis wurde nach einer Hygienephase aus der tiefsten Tasche jedes Quadranten eine mikrobiologische Probe entnommen. Mithilfe der PCR- Technik (micro-IDent®, Hain Lifescience) wurde die Konzentration von A. actinomycetemcomitans (Aa), P. gingivalis (Pg), P. intermedia (Pi), T. forsythensis (Tf) und T. denticola (Td) bestimmt. Die mikrobiologische Untersuchung wurde drei und sechs Monate nach der Behandlung wiederholt. Jeder Quadrant wurde mit einer der folgenden Methoden randomisiert behandelt: 1) Handinstrumente (H, Minifive-Küretten, Hu-Friedy), 2) Laser (L, Er:YAG KEY III, KaVo), 3) Schall (S, SONICflex® LUX 2003, KaVo), 4) Ultraschall (U, Piezon Master 400, EMS). Die Befragung der Patienten hinsichtlich des subjektiven Empfindens der Behandlung erfolgte sowohl direkt nach dem Abschluss der Therapie als auch einen Monat später. Die statistische Auswertung der mikrobiologischen Befunde umfasste die GEE- und GENMOD-Prozedur (α = 0,0083; Signifikanzniveau nach Bonferroni-Korrektur). Die subjektive Patientenbeurteilung wurde mit dem Friedman- sowie Wilcoxon-Test analysiert (α = 0,0083; Bonferroni-Korrektur). Drei Monate nach der Behandlung zeigten alle Methoden eine signifikante Reduktion der gesamten Keimzahlen (p < 0,0001). Aa wurde in der H- und U-Gruppe signifikant verringert, während Pg, Pi, Tf und Td (p < 0,0083) in allen Gruppen signifikant reduziert wurden. Nach sechs Monaten stiegen die gesamten Keimzahlen in allen Gruppen wieder an (p < 0,0001), blieben jedoch in der L- (p = 0,0003), S- und U-Gruppe (p < 0,0001) signifikant geringer als zu Beginn der Behandlung. Aa erreichte in allen Behandlungsgruppen wieder die Ausgangswerte. Verglichen mit der Baseline war die Konzentration von Pg im sechsten Monat in der L- (p < 0,0001) und U-Gruppe (p < 0,0001) geringer. Pi und Tf blieben in der S-Gruppe reduziert (jeweils p = 0,0011 und p = 0,0002), während Td in der L- (p = 0,0031), S- (p = 0,0019) und U-Gruppe (p = 0,0049) signifikant niedrigere Konzentrationen aufwies. Der Vergleich der Behandlungsmethoden untereinander zeigte keinen signifikanten Unterschied. Die Befragungen der Patienten zu beiden Zeitpunkten zur Beurteilung der Therapiearten ergaben, dass die Ultraschallbehandlung als signifikant angenehmer bewertet wurde als die Behandlung mit den Handinstrumenten (p < 0,001 bei der ersten und p = 0,005 bei der zweiten Befragung) und dem Laser (p = 0,002 bei der ersten und p = 0,006 bei der zweiten Befragung). Alle vier Behandlungsmethoden können die subgingivalen Pathogene vorübergehend signifikant reduzieren. Die Patienten bevorzugten die Behandlung mit Ultraschall.Aim: To evaluate and compare the bactericidal effects of hand instruments, Er :YAG-laser, sonic and ultrasonic scalers in patients with chronic periodontitis. Patient perception of each treatment was documented. Materials and Methods: From 72 patients, bacterial samples were collected from the deepest pocket in each quadrant (total: 288 sites). A PCR-kit monitored the concentration of Actinobacillus actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi), Tannerella forsythensis (Tf), and Treponema denticola (Td) at baseline as well as three and six months after therapy. One quadrant in each patient was randomly assigned to: curettes (H-group); Er:YAG-laser (L-group); sonic device (S-group); or ultrasonic device (U-group). Results: Three months postoperatively, the concentrations of Pg, Pi, Tf and Td were significantly reduced in all groups. Laser and sonic instrumentation failed to reduce Aa. Six months after therapy, significant differences were still detected for Pg (L- and U-group), for Pi and Tf (S-group), and for Td (L-, S- and U-group). Patients rated ultrasonic treatment as more pleasant than hand and laser instrumentation. Conclusion: The various treatment methods resulted in a comparable overall reduction of the periodontal pathogens, and pocket recolonisation was not different six months postoperatively. Ultrasonic instrumentation had more impact on patient comfort

A comparison of Er:YAG laser and mechanical debridement for the non-surgical treatment of chronic periodontitis: A randomized, prospective clinical study

Aims To compare a monotherapy of Er:YAG laser debridement (ERL), wavelength 2940 nm, with mechanical scaling and root planing (SRP) for the treatment of chronic periodontitis using clinical and patient-centred outcomes. Methods Twenty-eight participants had two randomly assigned quadrants treated with ERL and two with SRP. Full-mouth plaque index, probing depth, bleeding on probing, clinical attachment level and gingival recession were recorded at baseline and 6- and 12-weeks post therapy. A questionnaire was used to assess pain, discomfort and satisfaction during and after treatment. Results Twenty-two participants completed treatment and had 6- and 12-week clinical re-evaluations. SRP provided greater mean pocket depth reduction at 6- and 12-weeks (p similar to 0.01 and p similar to 0.003 respectively), and a greater reduction in pockets similar to 4 similar to mm at 6 similar to weeks only (p similar to 0.03) compared with ERL. SRP also resulted in a significant reduction in bleeding on probing (BOP) sites at 12 similar to weeks compared with ERL and a statistically significant greater reduction in mean clinical attachment level (CAL) at 6- (p similar to 0.02) and 12-weeks (p similar to 0.03). Patients expressed greater satisfaction with SRP on the day of treatment but were equally satisfied subsequently. Conclusion SRP resulted in a statistically significant greater short-term improvement in clinical parameters and patient satisfaction compared with ERL

Periodontopathogen levels following the use of an Er:YAG laser in the treatment of chronic periodontitis

BackgroundInflammatory periodontal diseases are initiated by microbial biofilms. The reduction of the biofilm is important in the management of the disease. This study compares periodontopathogen levels following the treatment of chronic periodontitis using Er:YAG laser (ERL) debridement and mechanical scaling and root planing (SRP). MethodsUsing a split-mouth design, two quadrants were randomly allocated for treatment. Two hundred and fifty-two subgingival plaque samples were collected from 21 patients, before treatment (baseline) and at 6 and 12 weeks post-therapy. Multiplex qPCR was used to determine relative levels of Porphyromonas gingivalis (Pg), Treponema denticola (Td), Tannerella forsythensis (Tf), and Aggregatibacter actinomycetemcomitans (Aa). ResultsTf and Pg were significantly reduced post-treatment for both ERL and SRP. ERL treatment resulted in a reduction of Td at 12 weeks. Following SRP treatment Aa was significantly reduced at 12 weeks. No statistically significant difference was seen when treatments were compared at 6 and 12 weeks. ConclusionsA comparable reduction in the level of the four periodontal pathogens assayed was achieved with Er:YAG laser debridement and mechanical scaling and root planing