Early and 24-hour bond strength and degree of conversion of etch-and-rinse and self-etch adhesives

PURPOSE: To evaluate early and 24-hour microtensile bond strength (microTBS) and the degree of conversion (DC) of one representative adhesive system from each of the four current bonding approaches. METHODS: 40 human molars were sectioned occluso-gingivally into two halves. Resin composite was bonded incrementally to flat, mid-coronal dentin, using the adhesives Adper Scotchbond MP (MP); Adper Scotchbond 2 (SB); Clearfil SE Bond (SE); and Adper Prompt L-Pop (LP) according to the respective manufacturer's instructions (n = 10). One half was immediately sectioned into sticks and subjected to muTBS test. As the sectioning process took approximately 1 hour, the results were designated as 1-hour bond strengths. The other half was stored in distilled water at 37 degrees C for 24 hours before being sectioned and tested. The DC of these systems was measured using Fourier Transform-Raman spectroscopy in three periods: immediately, 1 and 24 hours after polymerization. Data were analyzed with ANOVA and Tukey's tests. RESULTS: There were no significant differences between the 1-hour and 24-hour bond strengths (P > 0.05), or among the DC measured immediately, 1 hour and 24 hours after polymerization (P > 0.05). However, significant differences were observed among adhesives (P < 0.05). microTBS values obtained, in MPa (1 hour/24 hour), were: SB (48.6 + 1.3/48.4 + 3.5) = SE (51.9 + 4.7/53.3 +/- 2.9) > MP (35.3 +/- 10.9/38.6 + 6.7) > LP (25.5 + 1.1/26.0 + 1.5). The DC, in percentage (immediately/1 hour/24 hour), were: SE (81/82/87) > MP (79/77/81) > SB (60/63/65) > LP (39/37/42).     

Colour and translucency of opaque-shades and body-shades of resin composites

The purpose of this study was to evaluate the optical properties--not only the translucency but also the colours--of opaque-shade resin composites. The CIELAB parameters (L*, a* and b*) of disks of A2 and opaque A2 (OA2) shades of Charisma (Heraeus-Kulzer), Solare (GC) and Filtek Supreme (3M) were evaluated on backings of black, white and the material itself to calculate the translucency parameter (TP) and the colour differences (delta E*) between A2 and OA2. A two-way analysis of variance (anova) for the TP indicated a less statistically significant TP value in the OA2 shade than the A2 shade for all products. As for the products, Charisma showed a statistically greater TP value than the other two products. Regarding the delta E* between A2 and OA2, all the products revealed clinically perceptible colour differences (delta E* > 3.3). Hence, we must take the colour differences of opaque-shade resin composites into consideration, as well as the translucency of the materials, for a clinically acceptable colour match of the restoration.     

Levels of evidence and journal impact factor in oral and maxillofacial surgery

The aim of this study was to identify the relationship between quality of research, in terms of levels of evidence, and journal impact factor (IF), and to describe the pattern of publications in oral and maxillofacial surgery. All four major journals in this subject area only, and with a published IF, were included in the study. Latest published IF dated 2004 was chosen, and all articles related to its calculation were accessed and classified into four levels of evidence. Correlation between levels of evidence and IF was investigated and the pattern of publications was described. All eligible 932 published articles were analysed. None (0%) were level I evidence, 20 (2%) were Level II, 70 (8%) level III and 337 (40%) level IV; 465 (50%) articles were classified as non-evidence. IF ranged from 0.689 to 1.154. There were statistically significant correlations between levels of evidence and IF (rho=1.0, P<0.01). Among the 465 non-evidence articles, there were 219 (47%) case reports, 91 (20%) animal studies, 52 (11%) laboratory studies, 35 (8%) technical notes, 24 (5%) tutorial articles, and 16 (3%) reviews articles.     

Microstructural characterization and fracture behavior of a microhybrid and a nanofill composite

OBJECTIVES: To characterize the microstructure and composition of two different composites, and to determine their influence on the physical properties and fracture behavior. METHODS: The microstructure and composition of a microhybrid (Filtek Z250-Z2) and a nanofill (Filtek Supreme-SU) composite were analyzed using scanning electron microscopy (SEM) and electron dispersive spectroscopy (EDS). Filler wt% was determined by thermogravimetric analysis. Hardness (H) and degree of conversion (DC) were evaluated at top and bottom surfaces of 2-mm thick specimens, and the dynamic elastic modulus (E) was determined with ultrasonic waves. Bar specimens (n=30) were subjected to flexure loading and flexural strength (sigmaf) was calculated (MPa). Fractographic analysis (FA) was performed to determine the fracture origin (c) for calculation of fracture toughness (KIc), and these results were compared to those from the single edge notch beam (SENB) method. Results were statistically analyzed using two-way ANOVA, Student's t-test and Weibull analysis (alpha=0.05). RESULTS: Z2 had higher filler wt%, H, E and DC at 2-mm depth as compared with SU. The fracture behavior (sigmaf and KIc) and the structural reliability (m) of the composites were similar. Results of KIc tested by SENB or calculated from fracture surfaces from flexure testing were similar. SIGNIFICANCE: The microstructural organization of the composites determines their physical properties, in spite of the similar filler content. In contrast, the microstructure did not influence the fracture behavior and the structural reliability of these highly filled composites. FA was shown to be a reliable method for determining the KIc of composites.     

A study of the bending resistance of implant-supported reinforced alumina and machined zirconia abutments and copies.

OBJECTIVES: The purpose of the present study was to evaluate the bending resistance of implant-supported CAD/CAM-processed restorations made out of zirconia or manually shaped made out of reinforced alumina. METHODS: Units of abutments and copies made of (i) a prefabricated hot isostatic pressed (HIPed) yttrium oxide partially-stabilized zirconia (Y-TZP) (Denzir), (ii) a prefabricated densely-sintered magnesia partially stabilized zirconia (Mg-PSZ) (Denzir-M) or, copies made of (iii) a prefabricated partially-sintered, porous reinforced alumina ceramic (RN synOcta-In-Ceram) were subjected to static loading perpendicularly at the long axis. The abutments were attached to either stainless steel analogs or titanium implant fixtures. The Y-TZP and Mg-PSZ copies were bonded onto the ceramic abutments with a dual-cured resin composite (Rely-X Unicem). Units of titanium abutment attached to a titanium implant fixtures were used as reference. RESULTS: The units comprising Denzir abutments as delivered (p<0.05) and heat-treated Denzir copies bonded to the Denzir abutments as delivered (p<0.01) and attached to stainless steel analogs exhibited significantly higher bending resistance than the control. The heat-treated Denzir copies bonded to the heat-treated Denzir M abutments attached to titanium implant fixtures and the In-Ceram specimens attached to stainless steel analogs showed significantly (p<0.05) lower bending resistance than the heat-treated Denzir copies bonded to the Denzir abutments as delivered and attached to stainless steel analogs. No statistically significant (p>0.05) differences were seen among the other groups studied. SIGNIFICANCE: All the ceramic abutments and copies exhibited values that were equal or superior to that of the control and exceeded the reported value, up to 300 N, for maximum incisal bite forces. To assess the clinical behavior long-term clinical studies should be conducted.     

Protective effect of different tetrafluorides on erosion of pellicle-free and pellicle-covered enamel and dentine

The aim was to analyze the protective effects of titanium, zirconium and hafnium tetrafluorides on erosion of pellicle-free and pellicle-covered enamel and dentine in vitro. Eight groups of 20 specimens each of bovine enamel and bovine dentine were prepared. Half the specimens in each group were immersed in human saliva for 2 h for pellicle formation. Specimens were then left untreated (controls) or were treated for 120 s with TiF(4), ZrF(4) or HfF(4) solutions (0.4 or 1%) or 1.25% AmF/NaF gel. All specimens were eroded by exposure to hydrochloric acid, pH 2.6, for 25 min. Cumulative calcium release into the acid was monitored in consecutive 30-second intervals for 5 min, then at 2-min intervals up to a total erosion time of 25 min using the Arsenazo III procedure. Data were analyzed by ANOVA. 1% TiF(4) solution offered the best protective effect, especially in dentine (reduction of calcium loss about 50% at 25 min). 1% ZrF(4), 1% HfF(4) and 0.4% TiF(4) also reduced calcium loss, but to a lesser extent. Long-term effects were limited to dentine, while reduction of enamel erosion (about 25%) was restricted to 1-min erosion. The fluoride gel had a protective effect only in dentine. The efficacy of the tetrafluorides was influenced by the presence of the pellicle layer, in that the protection against dentine erosion by TiF(4) and ZrF(4) was greater on pellicle-covered specimens. Tetrafluoride solutions, especially 1% TiF(4), could decrease dental erosion, but were more effective on dentine than on enamel.     

On mechanical behavior of molecular composite resins reinforced with polyaramides. Molecular motion of Oct-PPTA and Ste-PPTA and thermal properties and dynamic viscoelasticity of Oct-PPTA-PMMA and Ste-PPTA-PMMA

Molecular composites, composed of polymethylmethacrylate (PMMA) resin as matrix reinforced with polyaramides as a rigid core molecule have been developed to produce a denture base polymer with improved dental material properties. N-substituted polyaramides were prepared via metalation using sodium methylsulfinylcarbanion, followed by the reaction with corresponding octyl bromide and/or stearyl bromide in dimethyl sulfoxide. In these molecular composite resins (called Oct-PPTA-PMMA and Ste-PPTA-PMMA short) compounding 3 wt% of N-octylated-PPTA (Oct-PPTA) and/or N-stearylated-PPTA (Ste-PPTA) to PMMA, their dental material properties were in the order of Oct-PPTA-PMMA greater than Ste-PPTA-PMMA greater than or equal to PMMA. Their polymer properties were analyzed to molecular level, using nuclear magnetic resonance (NMR) spectroscopy, thermogravimetric (TG) analysis and dynamic mechanical thermal analysis (DMTA). The molecular motion of the methyl group of Oct-PPTA proved to be constrained for the rigid main chain by T1 (inversion recovery method) NMR spectra in CDCl3 while that of Ste-PPTA was not affected. The thermal properties of the composites were in the order of Oct-PPTA-PMMA greater than Ste-PPTA-PMMA greater than PMMA by TG analysis, and the dynamic storage modulus values were Oct-PPTA-PMMA greater than Ste-PPTA-PMMA greater than PMMA in the region from rubbery state to viscous flow state by DMTA.     

Effectiveness of primer and bond in sealant retention and caries prevention

PURPOSE: The purpose of this clinical trial was to test the use of a primer and bonding agent to increase the retention of a fissuresealant in a group of Kuwaiti children. METHODS: In 78 6- to 9-year-old children who required sealants in all 4 permanent frst molars, sealants were placed in 2 teeth using a primer and bond (3M Scotch Bond) and in 2 teeth without primer and bond. Sealant retention was evaluated 1 and 2 years later. Sealant retention was scored as: (1) complete retention; (2) partial loss of sealant; and (3) complete loss of sealant Caries was scored for those teeth in which the sealant was partially or completely lost RESULTS: At the 2-year examination, in teeth sealed with primer and bond (a) 64% of the sealants were completely retained; (b) 23% were partially lost; and (c) 13% were completely lost. In teeth sealed without primer and bond: (a) 68% of the sealants were completely retained; (b) 20% were partially lost; and (c) 12% were completely lost There was no difference in sealant retention (P=.22) and caries (P=.56) in teeth sealed with and without bond. In multivariate analyses after controlling for age, gender, tooth surface, and arch, no differences in sealant retention and caries were seen. CONCLUSION: If a proper technique is used in sealant placement, primer and bond does not enhance sealant retention.     

Effects of injury and inflammation on pulpal and periapical nerves

Several studies dealing with the reactions of dental nerve fibers to injury and inflammation are reviewed in this article. The subgroup of dental nerve fibers that contains calcitonin gene-related peptide (CGRP) was examined by immunocytochemistry at various times (1 to 35 days) after one of three degrees of injury: (a) Mild: Four days after making shallow cavities into cervical dentin of first molars of anesthetized adult rats, we found that CGRP fibers had sprouted into the subjacent odontoblast layer and dentin, and then returned to normal by 3 wk. (b) Intermediate: If the cervical cavities were acid etched, we found damage to the odontoblast layer, microabscess formation, and sprouting of CGRP fibers near the abscess, with subsequent formation of reparative dentin and healing. (c) Severe: If the pulp was exposed, a variety of reactions could occur, the most prevalent of which was a severe necrosis leading to development of periapical lesions. Analysis of the progressive stages of pulpal abscess and necrosis showed sprouting CGRP nerve fibers (a) at the retreating interface between abscess and vital pulp; (b) in periapical areas during onset of lesions; and (c) around chronic abscesses in granulomatous periodontal tissues. These studies are discussed in relation to various dental clinical problems such as hypersensitive teeth, episodic toothache, early onset of periapical lesions, dental anesthesia, and possible roles for sensory fibers and neuropeptides in tissue defense and healing.     

Effects of gray and white mineral trioxide aggregate on the proliferation of oral keratinocytes and cementoblasts

Mineral trioxide aggregate (MTA) is used as a repair material and may directly contact cells from different cell lineages. The purpose of this study was to assess cell proliferation of immortalized Murine cementoblasts (OCCM.30) and immortalized keratinocytes (OKF6/TERT1) on gray MTA (GMTA) and white MTA (WMTA) with the DNA intercalating dye Hoechst 33342. Cells were grown for 72 hours on GMTA or WMTA that had been cured for 24 hours or 12 days. WMTA significantly (p < 0.001) increased the proliferation of OCCM.30 cementoblasts compared to control and OKF6/TERT1 keratinocytes. Both cell types grew significantly (p < 0.001) better on the surface of WMTA compared to GMTA. In addition, both cell types showed significantly (p < 0.005) higher proliferation when grown on 12-day-cured GMTA compared to 24-hour-cured GMTA.     

Correlation of crevicular fluid and serum levels of retinol-binding protein 4 and leptin in chronic periodontitis and obesity

Objective

Retinol-binding protein 4 (RBP4) and leptin are both adipokines and involved in the pathophysiology of different vascular and inflammatory diseases and selectively elevated in patients with obesity. The aim of the present study was to determine and correlate the levels of RBP4 and leptin in gingival crevicular fluid (GCF) and serum in patients with chronic periodontitis (CP) and obesity.

Materials and methods

A total of 70 patients with age group 25 to 45 years were divided into four groups based on gingival index (GI), probing depth (PD), clinical attachment level (CAL), body mass index (BMI) and radiographic evidence of bone loss. The groups were (1) group I (non-obese periodontally healthy), (2) group II (obese periodontally healthy), (3) group III (non-obese with chronic periodontitis) and (4) group IV (obese with chronic periodontitis). The GCF and serum levels of human RBP4 and leptin were quantified using ELISA.

Results

An increase in RBP4 levels from group I to group IV was found in both GCF and serum. However, GCF leptin levels was found to be greatest in group II, then group I, group IV and group III showing the least while an increase in serum levels from group I to group IV was found. The GCF and serum values of the inflammatory mediator correlated with the evaluated periodontal parameters and with each other (p < 0.05).

Conclusion

RBP4 and leptin can be considered as possible GCF and serum markers of inflammatory activity in CP and obesity, which further longitudinal studies are needed.

     

Flexural strength of Cerec 2 machined and jointed InCeram-Alumina and InCeram-Zirconia bars.

OBJECTIVE. The flexural strength of Cerec 2 InCeram-Alumina and InCeram-Zirconia bars is evaluated. The focus of the in vitro study is to identify a jointing procedure for InCeram which may be used for producing full-ceramic fixed-partial-denture frameworks. METHODS. Six groups (n=15) of machined and jointed InCeram-Alumina (T1-T5) and InCeram-Zirconia (T6) bars (3x4x13mm(3)), respectively, were examined using a 3-point-bending test. InCeram-Alumina joint-free controls were: machined (C1), slip cast (C2, C3) and cut from the block (C4) bars. Machined joint-free InCeram-Zirconia bars were used as controls (C5). InCeram-Alumina slip was used for jointing T1-T5 and InCeram-Zirconia slip for bars T6. Bars were jointed in groups T1 and T2 using butt joint (S1), in T3 and T4 oblique (S2, S3) and in T5 and T6 rounded (S4) joint shapes. RESULTS. Two-way analysis of variance showed significant differences between materials (p<0.001) and jointing shapes (p<0.001). The rounded (S4) shape showed the highest flexural strength of 434 (65) MPa of InCeram-Alumina (T5) and 475 (54) MPa of InCeram-Zirconia (T6) bars, respectively but machined/joint-free InCeram-Alumina (511 (59) MPa, C1) and machined/joint-free InCeram-Zirconia (624 (58) MPa, C5) were significantly (p<0.01/p<0.001) stronger. No significant differences (p>0.05) were found between machined/jointed InCeram-Zirconia (475 (54) MPa, T6), joint-free InCeram-Alumina slip cast (498 (125) MPa, C2) and joint-free InCeram-Alumina machined bars (511 (59) MPa, C1). SIGNIFICANCE. Compared to conventional slip cast InCeram-Alumina the flexural strength of machined/jointed InCeram-Zirconia appears to be adequate for fixed-partial-denture frameworks.     

Prospective evaluation of a pragmatic treatment rationale: open reduction and internal fixation of displaced and dislocated condyle and condylar head fractures and closed reduction of non-displaced, non-dislocated fractures Part II: high condylar and condylar head fractures

This study prospectively evaluated closed reduction (CR) outcomes in non-displaced, non-dislocated high-condylar and condylar-head fractures (Class VI after Spiessl and Schroll) and open reduction and internal fixation (ORIF) of displaced (Class III) or dislocated (Class V) fractures. Thirty-eight patients with 54 fractures (16 (42%) with bilateral fractures, 14 (37%) CR, 24 (63%) ORIF) were enrolled in a 1 year follow-up that 18 patients with 33 fractures completed. Condylar translation in Class VI fractures recovered to 11 mm for vertical opening, 8mm for protrusion and 10 mm for mediotrusion; Class III synonymously 8 mm, 8 mm and 6 mm; and Class V 7 mm, 6mm and 7 mm; incisal movements recovered to 38 mm, 8 mm and 8 mm in Class VI; 55 mm, 7 mm and 10 mm in Class III with 1 (8%) malocclusion, 1 (8%) impaired vertical opening and 55 mm, 7 mm and 9 mm in Class V with 2 (18%) malocclusions. Fragment-reduction versus the non-fractured condyle was -0.3 mm to +1.3 mm and +3 degrees to +9 degrees in Class VI, -1 mm to -0.2 mm and +3 degrees to +2 degrees in Class III, -3.3 mm to +3.1 mm and -11.2 degrees to +1 degrees in Class V. Malocclusion and joint locking were unreliable determinants for a treatment decision, being forged by concomitant fractures. Joint movements were within normal range at 1-year follow-up except Classes III and V vertical opening translation. After predefined criteria, 92% successful outcomes were attained. Multiple factor analysis should be used to prospectively evaluate the unacceptable clinical outcomes. Class VI fractures with intact vertical support should prospectively be evaluated whether these benefit from ORIF.     

自酸蚀与全酸蚀粘接剂对牙釉质和牙本质的剪切粘接强度比较

目的 比较自酸蚀与伞酸蚀粘接剂对牙釉质和牙本质剪切粘接强度,以期为临床提供参考.方法 选择因牙周病拔除的上颌中切牙20颗,使用两种自酸蚀粘接剂[A(ClearfilTM Protect Bond)、B(AdporTM PromptTM)]和两种全酸蚀粘接剂[C(SwissTEC SL Bond)、D(Single Bond)]按照厂家推荐步骤对牙釉质和牙本质进行粘接,并测试牙釉质和牙本质粘接样本的剪切粘接强度.结果 4种粘接剂对牙釉质和牙本质粘接强度分别为:粘接剂A(25.33±2.84)、(26.07±5.56)MPa;粘接剂B(17.08±5.13)、(17.93±4.70)MPa;粘接剂C(33.14±6.05)、(41.92±6.25)MPa;粘接剂D(22.51±6.25)、(21.45±7.34)MPa.粘接剂C对牙釉质和牙本质剪切粘接强度显著高于其他3种粘接剂(P<0.05);粘接剂B的剪切粘接强度显著低于其他3种粘接剂(P<0.05).结论 本研究所选用的自酸蚀两步法粘接剂的剪切粘接强度与部分伞酸蚀粘接剂相当,高于自酸蚀一步法粘接剂.     

Radiographic defect depth and width for prognosis and description of periodontal healing of infrabony defects.

BACKGROUND: The aims of the present study were to evaluate 1) defect depth and width as a prognostic factor and 2) change in defect width as a describing parameter of periodontal healing in infrabony defects treated by regenerative therapy after 6 and 24 months. METHODS: In 24 patients with advanced periodontitis, 39 infrabony defects were treated by guided tissue regeneration (GTR) using expanded polytetrafluoroethylene (ePTFE) (n = 7) or bioabsorbable barriers (n = 32). Clinical parameters were assessed and 39 standardized radiographs (in triplicate) were taken before and 6 and 24 months after surgery. Using a computer-assisted analysis, the depth, width, and angle of the bony defects were measured. RESULTS: Statistically significant vertical clinical attachment gains (CAL-V: 3.15 +/- 1.63 mm to 3.31 +/- 1.65 mm; P<0.001) and bony fill (1.30 +/- 2.53 mm; P<0.01 to 1.54 +/- 2.70 mm; P<0.005) were observed 6 and 24 months postsurgically. In a multilevel regression analysis CAL-V gain was predicted by baseline CAL-V (P <0.0001), actual smoking (P <0.05), and age (P <0.1). Bony fill could be predicted by baseline height of the infrabony component (P<0.0001), gingival index at baseline (P<0.05), and actual smoking (P <0.01). In narrow (<26 degrees) and deep (> or = 3 mm) infrabony defects bony fill was more pronounced than in wide and shallow defects (P <0.05). CONCLUSIONS: Improvement achieved by guided tissue regeneration in infrabony defects can be maintained up to 24 months after surgery. Narrow and deep infrabony defects respond radiographically and to some extent clinically more favorably to GTR therapy than wide and shallow defects. However, depth of the infrabony component was a stronger prognostic parameter than defect angle. Actual smoking impairs the results of GTR therapy in infrabony defects.     

An in vitro comparison of retentive force and deformation of acetal resin and cobalt-chromium clasps

STATEMENT OF PROBLEM: The use of metal clasps on anterior teeth may cause esthetic problems. Recently, acetal resins have been used as an alternative tooth-colored denture clasp material to improve esthetics. However, there are few studies to support acetal resin use. PURPOSE: The purpose of this in vitro study was to compare the retentive force and deformation of acetal resin and cobalt-chromium clasps after 36 months of simulated clinical use. MATERIAL AND METHODS: Forty clasps each of acetal resin (1.2 or 2.0 mm thick) and cobalt-chromium (Dentorium)(1.2 mm thick) were fabricated using half-round standard prefabricated clasp patterns. The groups were further subdivided (n=10) into the type of tooth (premolar or molar metal model) and undercut (0.25 mm or 0.50 mm). The retentive force of the clasps was measured in distilled water by a specially designed insertion-removal testing apparatus with intervals corresponding to 0, 6, 12, 18, 24, 30, and 36 months of simulated clinical use of a removable partial denture. The distance between the clasp tips (mm) was measured with a microscope before and after the insertion-removal testing procedure. Comparison of the mean values of the retentive force (gram force) of the clasps and the distance (mm) between the clasp tips was conducted with 3-way analysis of variance and a Least Significant Difference (LSD) multiple range test (alpha=.05). RESULTS: The mean values of tensile load required to dislodge acetal resin clasps with 1.2-mm thickness (111.6 g or 0.11 N) and with 2.0-mm thickness (178.4 g or 1.75 N) was significantly lower than that to dislodge Co-Cr clasps (694.1 g or 6.81 N) (P<.001). The retentive force needed to dislodge all 3 types of clasps was significantly lower for the molar than premolar models and also lower for the models with 0.25-mm undercuts than for those with 0.50-mm undercuts (P<.001). After 36 months of simulated clinical use, there was evidence of deformation in the cobalt-chromium clasps but no deformation noted for the acetal resin clasps. The retentive force of cobalt-chromium clasps (297.4 g or 2.91 N) after deformation remained significantly higher (P<.001) than the retentive force of acetal resin clasps that were 1.2 mm (110.7 g or 1.08 N) and 2.0 mm thick (177.5 g or 1.74 N), respectively. CONCLUSION: Within the limitations of this study, the results suggest that both thicknesses of acetal resin clasps evaluated required less force for insertion and removal than Co-Cr clasps over a simulated 36-month period.     

Influence of splints and temporary crowns upon electric and thermal pulp-testing procedures.

The influence of different splints and temporary crowns upon the reliability of electric and thermal pulp-testing procedures was examined in 10 patients with vital maxillary central incisors and 10 patients with vital maxillary central incisors and 10 patients with unilateral pulp necrosis of a central incisor. The pulp-testing procedures were: (1) Bofors Pulp Tester, (2) Siemens Sirotest, (3) heated guttapercha, (4) ice, and (5) carbon dioxide snow (Odontotest). The splints or temporary crowns were: (1) silver cap splint, (2) acrylic cap splint, (3) Hawley orthodontic plate, (4) Saur's arch bar, (5) orthodontic bands, (6) stainless steel crown, and (7) stainless steel crown with labial surface removed. A reliable electrometric pulp response could only be elicited if the pulp tester was applied directly upon enamel and preferably upon the incisal edge. In this instance metal splints or partial steel crowns applied to the tooth had no effect on the pain threshold. A false positive reaction in case of pulp necrosis was only elicited when the electrode was placed directly upon metal which contacted neighboring vital teeth. The use of ice and heated guttapercha appeared to be of limited value, due to inconsistent pulp responses. Carbon dioxide snow gave a reliable response, unless applied on the incisal edge.     

Initial outcome and long-term effect of surgical and non-surgical treatment of advanced periodontal disease

AIM: A clinical trial was performed to determine (i) the initial outcome of non-surgical and surgical access treatment in subjects with advanced periodontal disease and (ii) the incidence of recurrent disease during 12 years of maintenance following active therapy. MATERIAL AND METHODS: Each of the 64 subjects included in the trial showed signs of (i) generalized gingival inflammation, (ii) had a minimum of 12 non-molar teeth with deep pockets (> or =6 mm) and with > or =6 mm alveolar bone loss. They were randomly assigned to 2 treatment groups; one surgical (SU) and one non-surgical (SRP). Following a baseline examination, all patients were given a detailed case presentation which included oral hygiene instruction. The subjects in SU received surgical access therapy, while in SRP non-surgical treatment was provided. After this basic therapy, all subjects were enrolled in a maintenance care program and were provided with meticulous supportive periodontal therapy (SPT) 3-4 times per year. Sites that at a recall appointment bled on gentle probing and had a PPD value of > or =5 mm were exposed to renewed subgingival instrumentation. Comprehensive re-examinations were performed after 1, 3, 5 and 13 years of SPT. If a subject between annual examinations exhibited marked disease progression (i.e., additional PAL loss of > or =2 mm at > or =4 teeth), he/she was exited from the study and given additional treatment. RESULTS: It was observed that (i) surgical therapy (SU) was more effective than non-surgical scaling and root planing (SRP) in reducing the overall mean probing pocket depth and in eliminating deep pockets, (ii) more SRP-treated subjects exhibited signs of advanced disease progression in the 1-3 year period following active therapy than SU-treated subjects. CONCLUSION: In subjects with advanced periodontal disease, surgical therapy provides better short and long-term periodontal pocket reduction and may lead to fewer subjects requiring additional adjunctive therapy.     

Influence of splints and temporary crowns upon electric and thermal pulp-testing procedures

abstract – The influence of different splints and temporary crowns upon the reliability of electric and thermal pulp-testing procedures was examined in 10 patients with vital maxillary central incisors and 10 patients with unilateral pulp necrosis of a central incisor. The pulp-testing procedures were: (1) Bofors Pulp Tester®, (2) Siemens Sirotest®, (3) heated guttapercha, (4) ice, and (5) carbon dioxide snow (Odontotest®). The splints or temporary crowns were: (1) silver cap splint, (2) acrylic cap splint, (3) Hawley orthodontic plate, (4) Saur's arch bar, (5) orthodontic bands, (6) stainless steel crown, and (7) stainless steel crown with labial surface removed. A reliable electrometric pulp response could only be elicited if the pulp tester was applied directly upon enamel and preferably upon the incisal edge. In this instance metal splints or partial steel crowns applied to the tooth had no effect on the pain threshold. A false positive reaction in case of pulp necrosis was only elicited when the electrode was placed directly upon metal which contacted neighboring vital teeth. The use of ice and heated guttapercha appeared to be of limited value, due to inconsistent pulp responses. Carbon dioxide snow gave a reliable response, unless applied on the incisal edge.     

Signs and symptoms of temporomandibular disorders and the incidence of tinnitus

In a cross-sectional analysis of data from the Study of Health in Pomerania (SHIP 0), temporomandibular disorders (TMD) were the strongest predictors for tinnitus beside headache. The aim of this study was to investigate whether signs and symptoms of TMD can be identified as risk factors for developing tinnitus. The SHIP 1 is a population-based 5-year longitudinal study intended to systematically describe the prevalence of and risk factors for diseases common in the population of Pomerania in northern Germany. A total of 3300 subjects (76% response) were reevaluated after 5 years for tinnitus and signs and symptoms of TMD using the same questionnaires and examination tools as baseline. To estimate the relative risk (RR) appropriately, a modified Poisson regression was used. After exclusion of prevalent cases with diagnosed tinnitus, 3134 subjects were analysed. Among the 191 exposed subjects with palpation pain in the temporomandibular joint (TMJ), 24 subjects (12·6%) received diagnosed tinnitus after 5 years, whereas among the 2643 unexposed subjects 142 subjects (5·8%) received tinnitus yielding a risk difference of 7·7% (95% confidence interval [CI]: 3·0%-12·5%) and a risk ratio of 2·60 (95% CI: 1·7-3·9). The risk ratio was 2·4 (95% CI: 1·6-3·7) after adjustment for gender, age, school education and frequent headache. Pain on palpation of the TMJ, however, did not worsen the prognosis for tinnitus in prevalent tinnitus cases (RR = 0·8, P = 0·288). Signs of TMD are a risk factor for the development of tinnitus.