Quintessence International, 09/2009

This article describes a novel approach to treat smooth-surface white spot lesions microinvasively. The technique is based on the infiltration of enamel caries lesions with lowviscosity light-curing resins called infiltrants. After the surface layer is eroded, the lesions are desiccated and a resin infiltrant is applied. The resin penetrates into the lesion microporosities driven by capillary forces and is subsequently hardened. Infiltrated lesions lose their whitish appearance and look similar to sound enamel. Additionally, the treatment prevents lesion progression. The proposed technique might be an alternative to microabrasion and restorative treatment, in particular for white spot lesions of esthetically relevant teeth. Keywords: caries, infiltrant, infiltration, penetration, resin, white spot

Contact mucositis is an inflammatory mucosal reaction caused by many agents. A case of a 53-year-old man with contact-type allergy in oral mucosa due to cinnamon chewing gum is presented. This condition should be considered in the differential diagnosis of nonspecific oral lesions. Keywords: allergic reaction, cinnamic aldehyde, cinnamon, hypersensitivity, oral mucosa, oral mucositis

Among the factors that influence the success of treatment of a root perforation, its location and possibility of contamination are determinant because the interaction of these 2 factors may result in significant periodontal injury. The management of cases of hard-to-reach contaminated perforations depends on the choice of an adequate technique. In the case reported in this article, controlled orthodontic tooth extrusion was successfully performed to treat gingival recession secondary to root perforation. The outcomes showed that this technique preserves the zone of attached gingiva, maintains the crown height, and prevents the involvement of the supporting bone tissue. The favorable clinical and radiographic conditions after 7 years of follow-up demonstrate the viability of this treatment approach. Keywords: controlled tooth extrusion, endodontic treatment, integrated multidisciplinary approach, integrated treatment approach, orthodontics, root perforation

Objectives: To assess the influence of restorative materials and load cusps on the fatigue resistance of endodontically treated molars. Method and Materials: Thirty extracted molars received root canal treatment followed by a standardized tooth preparation (3-mm cuspal reduction and immediate dentin sealing). Twenty Cerec 3 overlays (Sirona Dental Systems) were milled in the ceramic Vita MKII block (Vident; groups MKIIGL and MKIIGL-Z, oven-glazed), and 10 restorations were duplicated with a composite resin (Miris 2, Coltène/Whaledent; group M2). The fitting surfaces of the restorations were hydrofluoric acid etched (porcelain only) and silanated. Preparations were airborne-particle abraded and etched. All restorations were luted with preheated Filtek Z100 (3M ESPE) and subjected to cyclic isometric chewing (5 Hz) starting at 200 N (5,000 cycles), followed by stages of 400, 600, 800, 1,000, 1,200, and 1,400 N at a maximum of 30,000 cycles each. A stainless steel load sphere was used for groups MKIIGL and M2, while a composite resin load sphere was used in group MKIIGL-Z. All samples were loaded until fracture or to a maximum of 185,000 cycles. Groups were compared using the Kaplan-Meier survival curves (P = .05). Results: None of the molars restored with porcelain withstood all 185,000 loading cycles (survival = 0%). The mean fracture load for MKIIGL was 1,060 N and for MKIIGL-Z, 1,280 N. In group M2, the survival rate was 50%. The rate of fracture below the CEJ was 40%, 30%, and 20% for MKIIGL, MKIIGL-Z, and M2, respectively. Conclusion: Miris 2 overlays showed higher fatigue resistance than MKII porcelain (P = .01) when loaded with a stainless steel antagonist. Keywords: Cerec, composite resin, endodontically treated molars, fatigue resistance, overlay restorations, porcelain

Objective: To describe an innovative endoscopic technique for root canal treatment. Materials and Methods: Root canal treatment was performed on 12 patients (15 teeth), using a newly developed endoscope (Sialotechnology), which combines an endoscope, irrigation, and a surgical microinstrument channel. Results: Endoscopic root canal treatment of all 15 teeth was successful with complete resolution of all symptoms (6-month follow-up). Conclusion: The novel endoscope used in this study accurately identified all microstructures and simplified root canal treatment. The endoscope may be considered for use not only for preoperative observation and diagnosis but also for active endodontic treatment. Keywords: endoscope, root canal treatment

Objectives: To investigate the effect of abutment finish line curvature on the fit of allceramic CAD/CAM crowns and metal-ceramic crowns. Method and Materials: Three types of finish line curvature abutments (1-, 3-, and 5-mm curvature) were prepared on typodont maxillary central incisors. For each type of abutment, 5 all-ceramic crowns (Cercon system, DeguDent) and 5 metal-ceramic crowns were fabricated. The marginal gaps of copings and veneered crowns were measured on a profile projector. The data were calculated and analyzed with 2-way ANOVA and Tukey HSD test (α = .05). Results: The mean labial, lingual, mesial, and distal marginal gaps (SD) of all-ceramic crowns were similar: respectively, 54 (10), 51 (11), 47 (13), and 49 (9) µm for 1-mm curvature; 49 (12), 53 (11), 54 (10), and 55 (12) µm for 3-mm curvature; and 57 (12), 54 (11), 53 (10), and 52 (9) µm for 5-mm curvature. The mean labial, lingual, mesial, and distal marginal gaps (SD) of metal-ceramic crowns were 36 (7), 41 (9), 26 (8), and 28 (10) µm, respectively, for 1-mm curvature. The mean labial and lingual marginal gaps (SD) of metal-ceramic crowns for 3-mm curvature were 45 (8) and 48 (9) µm, respectively-significantly larger than mesial (P = .01 and .007) and distal (P = .03 and .02) gaps. The mean labial and lingual marginal gaps (SD) of metal-ceramic crowns for 5-mm curvature were 76 (10) and 74 (15) µm, respectively-significantly larger than mesial (P = .001 and .001) and distal (P = .001 and .001) gaps. Conclusions: The abutment finish line curvature had no significant effect on the marginal fit of all-ceramic crowns, but had a significant effect on the marginal fit of metal-ceramic crowns. Keywords: all-ceramic CAD/CAM crowns, finish line curvature, fit, metal-ceramic crowns

Objectives: To evaluate the influence of furcation anatomy and bone defect morphology on the treatment of Class II proximal furcations treated with enamel matrix derivative (EMD) proteins. Method and Materials: Eighteen Class II proximal furcations were treated with open-flap debridement + 24% EDTA conditioning + EMD proteins. Probing depth, gingival margin position, relative vertical and horizontal clinical attachment level, and vertical and horizontal bone levels were evaluated immediately before and 6 months after the surgeries. The changes in these parameters were correlated with vertical defect depth, number of walls, depth defect, interdental distance, root divergence, furcation distance, horizontal measure, root trunk, and furcation height, using the Pearson and Spearman rank correlation tests (α = 5%). Results: The depth defect correlated with gingival margin position (r = 0.52; P = .03), probing depth (r = 0.63; P = .005), and horizontal bone level (r = -0.46; P = .05). The furcation height also correlated with gingival margin position (r = 0.53; P = .02) and horizontal bone level (r = -0.57; P = .01). Moreover, the number of walls of vertical defect positively influenced relative vertical clinical attachment level (r = 0.47; P = .05). Conclusions: Within the limits of this study, furcation anatomy and defect morphology influence the clinical response of EMD protein therapy in Class II proximal furcation involvements. Keywords: clinical trial, enamel matrix derivative proteins, furcation lesions, furcation treatment, periodontal regeneration

Objective: To evaluate the effect of adhesive agents and fissure morphology on the microleakage and penetrability of pit and fissure sealants. Method and Materials: Sealants used in this study included Aegis (Bosworth), conseal f (Southern Dental Industries), and Admira Seal (Voco). Adhesive agents included Optibond Solo Plus (sds/Kerr) and Clearfil S3Bond (Kuraray). Ninety extracted permanent molars were randomly assigned to 9 groups combining sealant and adhesive agent materials. A sealant and control group (phosphoric acid etch only) was also included. Dye penetration (microleakage), penetrability, and fissure morphology assessment was performed for the treatment groups through microscopic evaluation. Results: Significant (P = .003) differences in microleakage were exhibited, with the Aegis + control and Aegis + Optibond Solo Plus groups displaying less leakage, while significant (P = .03) differences were also noted between groups regarding penetrability. Fissure morphology was not a significant (P = .82) factor affecting microleakage; however, fissure type did significantly (P .001) impact penetrability. No correlation was found between the extent of microleakage and penetrability. Conclusion: Application of sealants using phosphoric acid as a conditioning agent revealed superior results, while the use of adhesives was found to be unnecessary. Keywords: adhesive, fissure morphology, microleakage, pit and fissure sealant

Objectives: To evaluate the effect of 2 polishing systems on surface roughness of toothcolored restorative materials. Method and Materials: The materials included 3 flowable resins (Admira Flow, Voco; Dyract Flow, Dentsply; Filtek Flow, 3M ESPE) and a microhybrid composite resin (Filtek Z250, 3M ESPE). Eighteen specimens of each material were prepared using a Plexiglas well covered by a Mylar strip (10 mm in diameter and 2 mm in depth). The Ra (baseline) was measured with a Mitutoyo Surftest-402 Surface Roughness Tester (Mitutoyo) with a standard cut-off value of 0.8 mm. Five tracings at different locations on each specimen were made. The specimens were then randomly divided into two finishing and polishing groups (n = 9): (1) Sof-Lex Pop-on disks (3M ESPE), and (2) Astropol and Astrobrush system (Ivoclar Vivadent). After finishing and polishing, surface roughness of the specimens was remeasured. Data were analyzed using 1- and 2-way ANOVA, at P .05. Results: The Mylar strip produced the smoothest surface in all restorative materials, while 2-way ANOVA demonstrated a significant difference for the finishing and polishing procedures (P = .000). The smoothest surface was generated with Sof-Lex Pop-on disks for all the materials tested. In procedure 2 (diamond bur/Astropol and Astrobrush system), Admira Flow group received the highest average surface roughness value, and a significant difference was revealed between Admira Flow and the other resins (P = .001). Conclusion: Sof-Lex Pop-on disks produced a smoother surface than Astropol and Astrobrush silicone polishers for microhybrid and flowable composites. Keywords: flowable resins, surface roughness

Objective: To test casting capacities of impression materials under dry and wet sulcular conditions in vitro. Method and Materials: An incisor with a circular shoulder preparation (1 mm) was inserted in a primary mold. A shiftable secondary mold allowed adaptation of sulcular depth (1 to 4 mm). An outer circular chamfer assured reproducible positioning of an impression material carrier. Tested materials were PVS of differing viscosities (extra low, Panasil Contact Plus [ELV]; low, Affinis Light Body [LV]; and medium, Virtual Monophase [MV]) and one polyether material of low viscosity (Permadyne Garant [PE]). Impressions were made with sulcular depths of 1 to 4 mm in wet and 1 and 4 mm in dry conditions, cut in half, and digitized with a light microscope (Stemi SV8). Surface area of the region of interest (ROI, at inner angle of preparation) was determined with Optimas 6.2. Medians were calculated, and statistical analysis was performed using the Mann-Whitney U test (P = .05). Results: Median values of the measurements under wet condition demonstrated the smallest ROI areas for the ELV (297- 330[pixel]) and the MV (253-421[pixel]) materials followed by the LV (582-745[pixel]) and the PELV (544-823[pixel]). All materials showed significantly higher values for the wet compared to dry sulcular conditions. Repeated measurements showed no significant differences to the corresponding first determined series. Conclusion: The sulcus model is applicable to assess casting abilities of impression materials in clinically approximated sulcular conditions. The PVS materials with extra low and medium viscosities showed the best properties in dry and wet conditions. Keywords: dental elastomer, gingival fluid, precision impression

Objective: Inconsistencies among dentists in matching natural tooth shades have been documented. This study examined the reliability of a spectrophotometer in shade selection compared to visual method. Method and Materials: Nine observers with normal color vision were asked to visually and digitally match shades of nine maxillary models with incisors being replaced by Vita Classical shade guide tabs. The same test was carried out in vivo on nine subjects' maxillary central incisors. Observers included prosthodontists, dental technicians, and postgraduate students. Results: No significant difference was found among observers in shade selection regardless of the selection method. However, there was a significant difference between digital and visual methods in shade selection. Digital method was five times more likely to match the original shade color compared to visual method. Conclusion: The system does not solve all problems involved in the determination of a tooth shade. Vita Easyshade spectrophotometer was more likely to match the shade compared to visual method. Nevertheless, this system needs further refinement, as well as software upgrades. Shade-matching devices could help clinicians and technicians achieve a better shade choice. The combination of visual shade analysis and digital shade measurement together lies in the precise predictability of the miscibility of shades. Keywords: color, digital, Easyshade, spectrophotometer, visual