Dirk Ziebolz

Prevalence of periimplant disease in partially edentulous patients: a practice-based cross-sectional study

OBJECTIVESnEvaluation of the prevalence rates of periimplant mucositis and periimplantitis in partially edentulous patients in a private dental practice.nnnMATERIAL AND METHODSnThe data of 89 patients were collected (52 female, 37 male, age at time of implant placement: 51.8 ± 10.3 years). All patients had been treated with dental implants of the same type and fixed superstructures between January 1999 and June 2006 (observational period: 68.2 ± 24.8 months).nnnRESULTSnThe patient-related prevalence rate of periimplant mucositis (probing depth ≥ 4 mm and bleeding on probing [BOP]) was over all 44.9%. The respective rates in non-smokers without periodontal history were 30.4% and in smokers with periodontal history 80%. The multiple logistic regression analysis identified a significant association of mucositis with the independent variable smoker (odds ratio [OR] 3.77; P = 0.023). The patient-related prevalence rate of periimplantitis (probing depth ≥ 5 mm, BOP/pus, radiographic bone loss) was 11.2% (smokers with periodontal history: 53.3%, non-smokers: 2.8%). No periimplant disease was diagnosed in non-smoking patients without periodontal history and with a good compliance after treatment. Statistical analysis identified a significant association of periimplantitis with smoker (OR: 31.58; P<0.001) and compliance (OR: 0.09; P = 0.011). Periodontal history in general showed no significant association with periimplantitis.nnnCONCLUSIONSnSmoking and compliance are important risk factors for periimplant inflammations in partially edentulous patients.

Impact of toothpaste slurry abrasivity and toothbrush filament stiffness on abrasion of eroded enamel – an in vitro study

Objective. Toothbrush abrasion is significant in the development of tooth wear, particularly when combined with erosion. This in vitro study aimed to evaluate the impact of toothpaste slurry abrasivity and toothbrush filament stiffness on abrasion of eroded enamel. Material and methods. Eroded enamel samples (hydrochloric acid, pH: 2.6, 15 s) were brushed with 40 strokes in an automatic brushing machine using manual toothbrushes with different filament stiffness (filament diameter: 0.15, 0.20, or 0.25 mm). A paste-free control slurry (relative enamel abrasion (REA) value 2) and toothpaste slurries with different abrasivity (REA values 6 or 9) were used for brushing. Erosion and abrasion were followed by storing the enamel samples in artificial saliva for 3 h. After each 4th cycle, the samples were stored in artificial saliva for 15 h. After 60 cycles, enamel loss was measured by profilometry and statistically analyzed by two-way and one-way ANOVA and Bonferroni/Dunn post-hoc tests. Results. Loss of enamel (mean, µm) was influenced mainly by the abrasivity of the slurry and increased along with REA value (REA 2: 0.0–0.2, REA 6: 2.1–3.3, REA 9: 2.9–3.7). Abrasion of eroded enamel was also affected by filament stiffness of the toothbrush, but only groups brushed with toothpaste slurry of REA 6 showed any significant difference between the different toothbrushes. Thereby, toothbrushes with 0.2 mm filament diameter caused higher enamel loss than 0.15 and 0.25 mm filaments. Conclusions. Toothbrush abrasion of eroded enamel is influenced mainly by the abrasivity of the toothpaste slurry, but is also modified by toothbrush filament stiffness.

Efficacy and oral side effects of two highly concentrated tray-based bleaching systems

The aim of this study was to investigate the tooth-whitening efficacy and oral side effects of the two tray-based bleaching systems Visalys whitening (VW) and Opalescence PF (OP). A stratified, randomised distribution of the subjects (nu2009=u200960) to two treatment groups was performed according to baseline tooth brightness (L* values) as determined by colourimeter and to the criteria smoker/non-smoker. Tooth colour was evaluated by measuring L*a*b* values generated from standardised digital image analysis with Adobe Photoshop® of the facial surfaces of the right central maxillary incisor. Tooth hypersensitivity, with intensity graded from 0 (no hypersensitivity) to 10 (high hypersensitivity), was assessed chair-side using an air syringe. After bleaching therapy, both treatment groups demonstrated significant improvements in tooth colour (pu2009≤u20090.05). A shift towards less yellow (−Δb*) and brighter (+ΔL*) tooth colour was observed. Δb* was significantly higher in the OP group in comparison to the VW group, ΔL* showed no significant difference between the both treatment groups (pu2009≤u20090.05). After bleaching, the intensity of tooth hypersensitivity was increased significantly compared to baseline in both groups (pu2009≤u20090.05), with no significant difference between the both groups. Both highly concentrated bleaching systems are effective as tooth-whitening systems, with few reported side effects such as transient tooth hypersensitivity.

Increased susceptibility for white spot lesions by surplus orthodontic etching exceeding bracket base area.

INTRODUCTIONnThere is a paucity of information with regard to the susceptibility of iatrogenic white spot lesion formation after inattentive, surplus orthodontic etching with 30% phosphoric acid and the subsequent provision or absence of adequate oral hygiene.nnnMETHODSnNinety sound enamel specimens were randomly allocated to 6 trial groups (n = 15 each) for etching with 30% phosphoric acid for either 15 seconds and standardized daily enamel brushing or no brushing, etching for 30 seconds with daily brushing or no brushing, or nonetched controls with brushing or no brushing. Nutritive acidic assaults were simulated by demineralization cycles 3 times per day for 1 hour with interim storage in artificial saliva. Lesion depths in terms of percentage of fluorescence loss (delta F, delta Q) and lesion extension compared with the baseline were assessed by using quantitative light-induced fluorescence after 2, 7, 14, 21, and 42 days. Etching duration, trial time elapse, and oral hygiene, as well as the significance of factor interactions, were analyzed with 3-way analysis of variance (α = 5%).nnnRESULTSnThe impact of the factors of enamel brushing, trial time elapse, and etching each had a comparably significant effect on lesion progression. The effect of surplus etching on white spot lesion formation was significantly enhanced by the simultaneous absence of enamel brushing and also the progression of trial time. The combination of 30 seconds of surplus etching with inadequate oral hygiene was especially detrimental.nnnCONCLUSIONSnExcessive surplus orthodontic etching of the complete labial enamel surface, instead of the bracket bases only, must be avoided to prevent iatrogenic white spot lesions. Etching times not exceeding 15 seconds are favorable.

Impulse debracketing compared to conventional debonding.

OBJECTIVEnTo evaluate impulse debonding compared to three conventional methods for bracket removal in relation to the damage caused to the enamel surface.nnnMATERIALS AND METHODSnNinety-six osteotomed third molars were randomly assigned to two study groups (n = 48) for bracket bonding with either a composite adhesive system (CAS) or a glass-ionomeric cement (GIC). These two groups were then each randomly divided into four subgroups (n = 12) according to the method of debonding using (1) bracket removal pliers, (2) a side-cutter, (3) a lift-off debracketing instrument, or (4) an air pressure pulse device. Following debonding and corresponding postprocessing with either a finishing bur (CAS) or ultrasound (GIC), the enamel surfaces were assessed for damage, adhesive residues, and the need for postprocessing using scanning electron microscopy and the Adhesive Remnant Index, and the surfaces were compared in terms of mode of removal and type of adhesive using Fishers exact test (alpha = 5%).nnnRESULTSnNo significant differences were found between the two different types of adhesives (CAS, GIC) in terms of the amount of damage to the enamel. Portions of enamel damage were found for impulse debonding/0%<bracket removal pliers/4%<lift-off debracketing instrument/17%<side-cutter/21%. The highest Adhesive Remnant Index grades were seen for impulse debonding. GIC residues after postprocessing using ultrasound were seen in 79%, compared to 48% after rotational postprocessing of CAS residues.nnnCONCLUSIONSnImpulse debonding provides a good alternative to conventional debonding methods, as the adhesion is usually separated at the bracket-adhesive interface, thereby avoiding enamel damage, independent of the adhesive used.

Technical and biological complications of single‐molar implant restorations

OBJECTIVESnRetrospective evaluation of the biological and technical complications in implant-supported single-tooth molar restorations performed in a private practice after functional periods of ≥4xa0years.nnnMATERIAL AND METHODSnSixty-five patients (34 females, age 51.7xa0±xa010.6xa0years) with 112 implants received annual follow-up examinations and participated in a maintenance program. The survival (in situ) and success (complication-free) rates of implants and superstructures were evaluated. Time-dependent peri-implantitis rates were calculated, and the influencing factors were identified using a multiple Cox regression.nnnRESULTSnThe implant survival rate was 100%. Three of 112 crowns required replacement (prosthetic survival ratexa0=xa098.1%). Thirty technical complications were observed: loss of retention (16), ceramic fracture (10), and screw loosening (4). The success rate of the superstructures was 79.0% after 7xa0years. Overall, 9.2% of the patients developed peri-implantitis (probing depth ≥5xa0mm, BOP, suppuration, bone loss ≥3.5xa0mm); (smokers: 41.6%, non-smokers: 1.8%). After 7xa0years, the time-dependent implant success rate (free of peri-implantitis) was 100% for non-smokers and 58.6% for smokers. Multiple analysis showed a significant effect of smoking (hazard ratio, 19.5; Pxa0=xa00.008) on peri-implantitis.nnnCONCLUSIONSnImplants with cemented single-tooth restorations in the molar region constitute a reliable treatment in private practice. Smokers have a significantly increased peri-implantitis rate.

Efficacy of different strategies in protecting enamel against demineralization during fixed orthodontic treatment

Background and objectiveSealant application is a common strategy for preventing enamel demineralization during multibracket treatment. The aim of this study was to assess the efficacy in enamel demineralization prevention of two fluoride-containing enamel varnishes compared to a non-fluoride varnish, weekly fluoride gel application, and a non-treated control group.Materials and methodsEnamel specimens obtained from 75 human upper permanent incisors were randomly allocated to five trial groups (each nu2009=u200915): A), ProSeal (Reliance), B), Maximum Cure® (Reliance), C), CervitecPlus (Ivoclar Vivadent, Schaan, Liechtenstein), D) elmex® gelée (GABA, Lörrach, Germany), and E), a non-treated control group. Groups A–C received a baseline varnish application, whereas group D specimens received a once weekly gel application for 2xa0min. Six demineralization cycles per day were carried out for 5xa0min each using 0.05xa0M citric acid, with the specimens stored in remineralization solution between cycles. Lesion depth expressed in percentage fluorescence loss (Δ-F in %) compared to baseline (T0) was assessed quantitatively with light-induced fluorescence (QLF) after 3 (T1), 7 (T2), 14 (T3), and 30 (T4) days globally and for each time point, and analyzed for compounds using the Kruskal–Wallis test (αu2009=u20095%), and additional one-sample Wilcoxon tests for each time/compound combination (Bonferroni-corrected α-levels α*u2009=u20090.05/4u2009=u20090.0125).ResultsSignificant fluorescence loss revealing greater lesion depth was detected in the untreated controls (E) at T3, and in groups A (ProSeal) and C (CervitecPlus) at T4. No significant Δ-F changes were seen in the specimens from groups B (Maximum Cure®) and D (elmex® gelée).ConclusionMaximum Cure® sealant seems to offer efficient protection against demineralization during fixed orthodontic treatment, as does weekly application of elmex® fluoride gel.ZusammenfassungHintergrund und ZielsetzungZur Prävention von Schmelzdemineralisationen während der Multibracket-Behandlung ist das Aufbringen von Versieglern üblich. Studienziel ist die Bestimmung der demineralisationsprotektiven Effizienz zweier fluoridhaltiger Versiegelungslacke im Vergleich zu einem nichtfluoridhaltigen Lack, einer wöchentlichen Fluoridgelapplikation und einer unbehandelten Kontrollgruppe.Material und MethodikSchmelzproben von 75 humanen, permanenten oberen Inzisivi wurden randomisiert 5 Studiengruppen zugeordnet (jeweils nu2009=u200915): A), ProSeal, B), Maximum Cure® (beide: Reliance Orthodontic Products, Itasca, IL, USA), C), CervitecPlus (Ivoclar Vivadent, Schaan, Liechtenstein), D), elmex® gelée (GABA, Lörrach, Deutschland), und E), einer unbehandelten Kontrollgruppe. Gemäß Herstellerangaben erhielten die Gruppen A bis C jeweils eine Baseline-Applikation, Gruppe D dagegen eine wöchentliche Gelapplikation für 2xa0Minuten. Sechs Demineralisationszyklen/Tag wurden für jeweils 5xa0Minuten mit 0,05xa0M Zitronensäure durchgeführt, bei zwischenzeitlicher Lagerung in einer Remineralisationslösung. Läsionstiefen wurden mittels lichtinduzierter Fluoreszenz (QLF) nach 3 (T1), 7 (T2), 14 (T3), und 30 (T4) Tagen als prozentualer Fluoreszenzabfall (Δ-F in %) mit den Baselinewerten (T0) quantitativ abgeglichen. Statistische Analysen erfolgten sowohl global als auch separat für jeden Zeitpunkt mit dem Kruskal-Wallis-Test (αu2009=u20095%) und zusätzlichen Wilcoxon-Tests für jede Zeitpunkt/Behandlungs-Kombination (Bonferroni-korrigiert α-Level α*u2009=u20090,05/4u2009=u20090,0125).ErgebnisseSignifikante Fluoreszenzverluste (als Zeichen sich vertiefender Läsionen) wurden in der unbehandelten Kontrollgruppe (E) ab T3 und für die Gruppen A (ProSeal) und C (CervitecPlus) ab T4 verzeichnet. Keine signifikanten Δ-F-Veränderungen wurden in den Gruppen B (Maximum Cure®) und D (elmex® Gelèe) festgestellt.SchlussfolgerungDie Versiegelung mit Maximum Cure® scheint ebenso wie die wöchentliche Applikation des Fluoridgels elmex® einen effizienten Schutz gegen Demineralisation während der festsitzenden Behandlung zu bieten.

Suitability of orthodontic brackets for rebonding and reworking following removal by air pressure pulses and conventional debracketing techniques

AIMnTo test the null hypothesis that there are no significant differences in the reusability of debonded brackets with regard to debonding technique and adhesive used.nnnMETHODnNinety-six osteotomed third molars were randomly assigned to two study groups (n = 48) for bonding of a 0.018-inch bracket (Ormesh, Ormco) with either a composite adhesive (Mono-Lok2; RMO) or a glass ionomer cement (GIC; Fuji Ortho LC;GC). Each of these two groups were then randomly divided into four subgroups (n = 12) according to the method of debonding using (1) bracket removal pliers (BRP; Dentaurum), (2) a side cutter (SC; Dentaurum), (3) a lift-off debracketing instrument (LODI; 3M-Unitek), or (4) an air pressure pulse device (CoronaFlex; KaVo). The brackets were subsequently assessed visually for reusability and reworkability with 2x magnification and by pull testing with a 0.017- x 0.025-inch steel archwire. The proportions of reusable brackets were individually compared in terms of mode of removal and with regard to adhesives using the Fisher exact test (alpha = 5%).nnnRESULTSnThe null hypothesis was rejected. Not taking into account the debonding method, brackets bonded with GIC were judged to a significant extent (81%; n = 39; P < .01) to be reworkable compared with those bonded with composite (56%; n = 27). All brackets in both adhesive groups removed with either the LODI or the CoronaFlex were found to be reusable, whereas 79% (46%) of the brackets removed with the BRP (SC) were not. The proportion of reusable brackets differed significantly between modes of removal (P < .01).nnnCONCLUSIONnWith regard to bracket reusability, the SC and the BRP cannot be recommended for debonding brackets, especially in combination with a composite adhesive.

Practice-based clinical evaluation of zirconia abutments for anterior single-tooth restorations.

OBJECTIVEnThis study aimed to determine the survival rate and prevalence of biologic and technical complications associated with single-tooth implants with all-ceramic abutments in the anterior region.nnnMETHOD AND MATERIALSnA total of 33 patients were restored with 50 anterior implants and temporarily luted all-ceramic crowns on prefabricated zirconia abutments. All of the patients subsequently received annual supportive maintenance; 27 patients (18 women, 22-74 years) with 42 implants participated in the final maintenance visit and were included in the study (follow-up 78.1 ± 27.0 months). The time-dependent survival rate (Kaplan-Meier) and the frequency of prosthetic complications (abutment fracture [AF], screw loosening [SL], fracture of veneering ceramics [VF], retention loss [RL]) and biologic complications (peri-implantitis) were calculated to determine the success rates.nnnRESULTSnNo implant loss (implant-related survival rate 100%) but one abutment fracture occurred throughout the entire observation period; therefore, the survival rate of the superstructures (in situ criterion) was 97.6% (95% confidence interval [CI] 0.930- 1.000) after 7 years. Eleven restorations were affected by prosthetic complications: RL (n = 4), VF (n = 5), and SL (n = 2). Peri-implantitis was diagnosed for two implants (probing depth > 5 mm, bleeding on probing [BOP]/suppuration, and bone loss > 3 mm) (implant-related peri-implantitis rate 4.8%). No restoration required replacement due to complications. The success rate (event-free restoration) was 75.9% (95% CI 0.636- 0.882) after 7 years.nnnCONCLUSIONSnConsidering the calculated survival rate, the application of all-ceramic zirconia implant abutments in the anterior region can be recommended as a reliable therapy in private practice. Fractures of veneering ceramics were the most common prosthetic complication.

Clinical Outcome of Double Crown-Retained Mandibular Removable Dentures Supported by a Combination of Residual Teeth and Strategic Implants.

PURPOSEnThere is a lack of data regarding the clinical outcome of removable partial dentures (RPDs) supported by a combination of residual natural teeth and implants placed in strategic positions. The aim of the present case series was to conduct a retrospective investigation of the clinical outcome of mandibular tooth-implant-retained partial dentures (TIRPD) rigidly retained via telescopic double crowns.nnnMATERIAL AND METHODSnBetween 1999 and 2010, 18 patients with reduced residual dentition (1 to 3 natural abutment teeth) and in need of an RPD received 1 to 3 implants in strategic positions for support of the removable prostheses. All TIRPDs were rigidly retained by telescopic crowns according to the Marburg Double Crown (MDC) technique; all prostheses were placed in a private practice. Tooth/implant survival and success rates, prosthetic maintenance requirements, and peri-implant parameters were analyzed retrospectively using patient records and clinical examinations during the final recall appointments. Only patients attending at least annual supportive post-implant hygiene therapy visits (SIT) were included.nnnRESULTSnAfter a mean functional period of 5.84 ± 3 years (range: 3.01-12.21), 14 patients with 14 dentures supported by 24 implants and 27 teeth (mean number of abutments: 3.6) were available for assessment. Four teeth (survival rate: 85.19%) and no implants (survival rate: 100%) were lost. Peri-implantitis was observed around one implant (4.17%). All 14 dentures were functional (survival rate: 100%) and required only limited maintenance (i.e., screw loosening, acrylic resin fracture repairs, relining) amounting to 0.086 treatments per patient per year (T/P/Y).nnnCONCLUSIONSnWithin the limitations of this case series, it can be concluded that TIRPDs retained via MDCs might represent a viable treatment option in mandibles with few remaining abutment teeth. Further long-term clinical evaluations with a greater sample size are needed for a more detailed evaluation of this treatment concept.