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Periodontal reconstructive surgery procedures seek to correct mucogingival defects, including gingival recession. This case report describes the use of a subepithelial connective tissue graft (SCTG) associated with root-end fillings using mineral trioxide aggregate (MTA) for the treatment of Miller Class II recession with root apex exposure. A partial-thickness double pedicle flap was made, followed by root preparation with curette and bur finishing. The exposed root apex was removed and the canal was filled with MTA. An SCTG taken from the palate was placed over the root surface and covered with the double pedicle flap. Twelve months after treatment, a reduction from 11 mm to 1 mm in gingival recession was achieved, covering 91% of the root. Repair in the periapical region was determined with radiographs. A 1.0-mm probing depth was measured, and no bleeding was observed on probing. There was an adequate keratinized tissue band, along with esthetic tissue contour and coloration. This case report serves as an example of how the grafting of subepithelial connective tissue can be successfully accomplished in tandem with MTA for the treatment of isolated Miller Class II gingival recession with root apex exposure. (Int J Periodontics Restorative Dent 2009;29:445-449.). [ABSTRACT FROM AUTHOR]

A tridimensional surface roughness test evaluation is a non-destructive method that can be used to perform a topographic analysis of different surface treatments for glass and quartz fiber posts. This study divided 75 fiber posts into three groups according to their manufacturer. Each group was divided into five subgroups (n =5), according to the surface treatment each received: immersion in hydrofluoric acid, sandblasting, immersion in hydrogen peroxide, sandblasting followed by immersion in hydrofluoric acid, or sandblasting followed by immersion in hydrogen peroxide. Surface roughness was measured using a tridimensional surface roughness test and analyzed with three-dimensional analysis software. Results were statistically analyzed using Student's t-test. The only surface treatment to modify the surface topography of glass and quartz fiber posts and provide a significant increase in roughness was sandblasting airborne-particle abrasion with 50 µ alumina at a distance of 30 mm, using 2.5 bars of pressure for five seconds. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the clinical performance of two flowable composites based on methacrylate and one based on ormocer in treating non-carious cervical lesions (NCCLs) after 48-month evaluation in a split-mouth double-blind clinical study design., Methods: A total of 183 restorations were performed on NCCLs using a universal adhesive system (Futurabond U, Voco GmbH) with selective enamel etching on 27 participants: two participants received twelve restorations each, three received nine restorations each, and 22 participants received six restorations each. Three different flowable composites were employed (n = 61): a low-viscosity methacrylate-based composite (GrandioSO Flow, LVM), a high-viscosity methacrylate-based composite (GrandioSO Heavy Flow, HVM), and an ormocer-based flowable composite (Admira Fusion Flow, ORM). All restorations were evaluated using FDI and USPHS criteria after 48 months. Statistical analysis was conducted using Kaplan-Meier Survival analysis and Kruskal-Wallis analysis of variance rank (α = 0.05)., Results: After 48 months, 17 restorations were lost: LVM 6, HVM 9, ORM 2. The retention rates (95 % confidence interval) were 89.4 % for LVM, 80.4 % for HVM, and 95.6 % for ORM, with a significant difference between HVM vs. LVM and HVM vs. ORM (p < 0.05). Minor defects were observed in 30 restorations for marginal staining criteria (LVM 12, HVM 10, ORM 8) and in 71 restorations for marginal adaptation criteria (LVM 24, HVM 20, ORM 27) without significant difference between groups (p > 0.05). No restorations showed postoperative sensitivity or recurrence of caries., Significance: The increased viscosity of flowable composites could reduce the clinical longevity in NCCLs after 48 months. Ormocer-based and low-viscosity methacrylate-based flowable composites showed a successful clinical performance in NCCLs after 48 months., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Objectives: The aim of this study was to evaluate the clinical performance of surface sealants associated with a bulk-fill composite in posterior restorations after 4 years., Methods: A total of 174 posterior restorations were performed on 57 participants using a self-etch adhesive system and a bulk-fill composite. The groups were then divided into the following categories: 1) without surface sealant (NoS), 2) with surface sealant Biscover (Bisco, SBi), and 3) with surface sealant Permaseal (Ultradent, SPe). Restorations were evaluated using FDI criteria at baseline and after 1 and 4 years. Statistical analysis was conducted using Kaplan-Meier survival analysis and the Chi-square test (α = 0.05)., Results: After 4 years, only one restoration was lost (1 in the NoS group). The fracture/retention rate (with 95% confidence interval) was 98% for NoS and 100% for both SBi and SPe (p = 0.76). The majority of secondary outcomes showed minor defects, with no significant differences among the groups (p > 0.05). However, significant differences were observed among the groups in terms of marginal staining and marginal adaptation (p = 0.03). In both items, twelve restorations (nine in NoS, one in SBi, and two in SPe) showed minor marginal discrepancies favoring the sealant groups (SBi and SPe)., Significance: Regardless of the use of surface sealants, the bulk-fill composite restorations showed excellent clinical performance after 4 years. However, the groups that received sealants showed better marginal adaptation and less marginal discoloration compared to those that did not receive sealants., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Objectives: To evaluate the clinical performance of a universal adhesive system (Futurabond U, Voco) when applied following different adhesive strategies in non-carious cervical lesions (NCCLs) after 5 years., Methods: Fifty participants were included. Futurabond U (Voco) was applied in NCCLs using four adhesive strategies (n = 50 each): only self-etch (SE); selective enamel etching + self-etch (SET + SE); etch-and-rinse with dry dentin (ERD); and etch-and-rinse with wet dentin (ERW). All cavities were restored with Admira Fusion composite resin (Voco). Restorations were evaluated after 1, 3, and 5 years using the World Federation criteria (FDI) and the modified United States Public Health Service (USPHS) criteria., Results: After 5 years, retention rates were 81 % (65.8-90.5) for SE, 87 % (73.2-94.4) for SET + SE, 84 % (69.6-92.6) for ERD, and 78 % (63.6-88.9) for ERW (p > 0.05). Thirty-five restorations were considered to have minor discrepancies in marginal adaptation at the 5-year recall (14 for SE, 9 for SET + SE, 6 for ERD, and 6 for ERW; p > 0.05). Sixteen restorations were detected as a minor marginal discoloration (6 for SE, 4 for SET + SE, 1 for ERD, and 5 for ERW; p > 0.05) and one restoration showed a recurrence of caries (1 for ERW; p > 0.05) at the 5-year recall. No restorations showed postoperative sensitivity after 5 years., Significance: NCCLs restorations using a universal adhesive showed satisfactory clinical performance after 5 years, regardless of the adhesive strategy., (Copyright © 2023 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.)

Objectives: This is a double-blind, split-mouth, randomized clinical study that aims to evaluate the influence of bulk-fill composite packaging presented in syringes (BSy) and capsules (BCa), and the effect of selective enamel etching (SEE) on the clinical performance of class I and II bulk-fill resin composite restorations after 24 months., Methodology: A total of 295 class I or class II restorations were performed on 70 patients. One universal adhesive was applied in all restorations. SEE was used in 148 restorations and self-etching mode (SET) in 147 restorations. After the adhesive application, cavities were restored with Filtek Bulk-fill Posterior Restorative in syringes (BSy), Filtek One Bulk-fill in capsules (BCa), or Filtek Supreme Ultra in syringes with the incremental technique (In). All restorations were evaluated using the FDI criteria after one week and after six, 12, and 24 months. Kaplan-Meier survival analysis and Pearson's Chi-square test were used (α=0.05) for statistical analysis., Results: After 24 months, 62 patients were evaluated and four restorations were lost due to fracture (one for SEEBSy, two for SEEIn, and one for SETIn). No significant differences in the fracture and retention rate were found between groups (p>0.05). SEE showed significantly fewer marginal adaptation defects than SET (p<0.05). BCa and BSy groups showed fewer marginal discrepancies compared to In (p<0.05). Restorations performed with BCa showed less color mismatch than BSy or In (p<0.05)., Conclusion: Although all restorations exhibited satisfactory clinical performance after 24 months of clinical service, the clinical behavior of class I and II restorations' improved when performed with a bulk-fill composite in capsules, mainly when associated with a universal adhesive applied with SEE.

Objectives: To evaluate the clinical performance of a new dual-cure universal adhesive system (Futurabond U, Voco) when applied using different application strategies in non-carious cervical lesions (NCCLs) after 36 months., Material and Methods: Futurabond U was applied in NCCLs of 50 subjects using four adhesion strategies (n = 50 restorations per group): only self-etch (SEE); selective enamel etching + self-etch (SET); etch-and-rinse with dry dentin (ERDry); and etch-and-rinse with wet dentin (ERWet). All cavities were restored using Admira Fusion composite resin (Voco). Restorations were evaluated after 36 months using the World Federation criteria (FDI) and the modified United States Public Health Service (USPHS) criteria., Results: The after 36-month retention rates were 87% (75-92%) for SEE, 94% (83-98%) for SET, 91% (80-97%) for ERDry, and 94% (83-98%) for ERWet. Forty-three restorations were considered to have minor discrepancies in marginal adaptation at the 36-month recall (18 for SEE, 12 for SET, 7 for ERDry, and 6 for ERWet; p > 0.05). One restoration was detected as a minor marginal discoloration at the 36-month recall (1 for SET; p > 0.05). No restorations showed postoperative sensitivity and caries recurrence at 36 months., Conclusion: The clinical performance of the Futurabond U did not depend on the employed bonding strategy, and it was considered reliable after 36 months of clinical evaluation. However, greater marginal discrepancy was observed in the self-etch groups., Clinical Relevance: NCCLs restorations using a dual-cure universal adhesive in self-etch and etch-and-rinse modes showed satisfactory clinical performance after 36 months., (Copyright © 2022. Published by Elsevier Ltd.)

Objectives: To evaluate the influence of different application strategies on the clinical behavior of an MDP-free universal adhesive placed in non-carious cervical lesions (NCCLs) over the course of 36 months., Materials and Methods: Thirty-one patients participated in this study (N = 31). One hundred twenty-four restorations were assigned to four groups: We used the self-etch strategy on groups with (SE-et) and without (SET) selective enamel etching, and the etch-and-rinse strategy on groups with dry (ER-D) and moist (ER-M) dentin. After applying the MDP-free universal adhesive (Xeno Select universal adhesive, Dentsply Sirona), cavities were filled using EvoluX composite resin (Dentsply Sirona). The restorations were evaluated at baseline and after 36 months according to World Dental Federation (FDI) and US Public Health Service (USPHS) criteria. Friedman's repeated-measures analysis of variance rank (α = 0.05) was used for statistical analysis., Results: We evaluated the 31 patients after 36 months. Forty-two restorations were lost (ER-D = 5, ER-M = 7, SE-et = 14, SET = 16). The 36-month retention/fracture rates (95% confidence interval) were 83.9% for ER-D, 77.4% for ER-M, 54.9% for SE-et, and 48.4% for SET. ER strategy showed better retention rate than SE strategy (p < 0.05). Thirty-four restorations (ER-D = 6, ER-M = 10, SE-et = 10, SET = 8) showed marginal staining per FDI criteria and 15 restorations (ER-D = 1, ER-M = 2, SE-et = 6, SET = 6) showed marginal staining per USPHS criteria. No restorations showed postoperative sensitivity or recurrence of caries., Conclusion: The retention rate of Xeno Select universal adhesive was poor, mainly in the self-etch strategy., Trial Registration: REBEC clinical registry under protocol RBR-4wh4sh., Clinical Relevance: MDP-free universal adhesive behavior depends on the bonding strategy used., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objectives: To evaluate the 5-year clinical performance of two-step etch-and-rinse adhesives in noncarious cervical lesions (NCCL)., Methods and Materials: The sample comprised 35 adults with at least two similar-sized NCCL. Seventy restorations were placed, according to one of the following groups: Adper Single Bond 2 (SB) and Ambar (AM). The restorations were placed incrementally using a resin composite (Opallis). The restorations were evaluated at baseline and after 6 and 18 months and 5 years using some items of the FDI criteria. The differences in the ratings of the two materials after 6 months, 18 months, and 5 years were performed with Friedman repeated measures ANOVA by rank and McNemar test for significance in each pair (α=0.05)., Results: Five patients did not attend the 60-month recall. No significant differences were observed between the materials for any criteria evaluated. Twenty-one restorations failed (12 for SB and 9 for AM) after 60 months. Thus, the retention rate for SB at 60 months were 55.6% for SB and 71% for AM (p=0.32). After 60 months, 12 restorations (6 for SB and 6 AM) showed some loss of marginal adaptation (p=1.0). Slight marginal discoloration was observed in 10 restorations (6 for SB and 4 AM; p=0.91). Five restorations (2 for SB and 3 for AM) showed recurrences of caries (p=1.0)., Conclusions: Both two-step etch-and-rinse adhesives-Adper Single Bond 2, a polyalkenoic acid-containing adhesive, and Ambar, a 10-methacryloyloxydecyl dihydrogen phosphate (MDP)-containing adhesive-showed acceptable clinical performance after 60 months., (©Operative Dentistry, 2022.)

Clinical Relevance: The use of filled adhesive systems does not influence the clinical performance of the adhesive restoration in noncarious cervical lesions., (©Operative Dentistry, 2021.)

Objective: A systematic review and a meta-analysis were performed to answer the following research question: Are there differences in the color match and surface texture of nanofilled/nanohybrid and hybrid composite in patients with direct posterior restorations?, Data: Randomized clinical trials that compared nanofilled/nanohybrid and hybrid composite in direct restoration in posterior teeth were included. For the analysis of the bias the risk of bias tool (RoB) was used. Meta-analyses of different pairs (nanofilled vs. hybrid and nanohybrid vs. hybrid composite) were conducted for surface texture and color match and other secondary outcomes at different follow-ups, using a random effects model. Heterogeneity was assessed with the Cochran Q test and I 2 statistics. GRADE was used to assess the quality of the evidence., Sources: A search was performed in PubMed, Scopus, Web of Science, LILACS, BBO, Cochrane Library and SIGLE, without restrictions. IADR abstracts (2001-2019), unpublished and ongoing trials registries, dissertations and theses were also searched., Study Selection: 28 studies remained. No study was considered to be at low RoB; four studies were judged to have high RoB, and the remaining were judged to have unclear RoB., Results: For the primary and secondary outcomes variables no significant differences were detected between nanofilled/nanohybrid restorations and hybrid composite restorations in any of the study follow-ups (p > 0.08). The body of evidence for surface texture and color match was classified as moderate or low., Conclusion: No evidence of difference was found between nanofilled/nanohybrid and hybrid composite in any of the clinical parameters evaluated., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The objectives of this double-blind randomized clinical trial were to compare (a) the clinical times and (b) the occurrence and severity of postoperative sensitivity, of posterior restoration that used a universal adhesive, in a self-etch or selective enamel-etching technique, along with incremental or bulk-fill composites (presented in syringes or capsules). A total of 295 posterior restorations were placed according to the following groups: SETB - self-etch/bulk-fill in syringe; SETC - self-etch/bulk-fill in capsules; SETI - self-etch/incremental; SEEB - selective enamel-etching/bulk-fill in syringe; SEEC - selective enamel-etching/bulk-fill in capsules; and SEEI - selective enamel-etching/incremental. Clinical time was assessed by a reason (s/mm3) between the total volume of resin inserted and the total time required to perform the restorations. Postoperative sensitivity was evaluated using two scales (Numeric Rating Scale and Visual Analogue Scale). Mean clinical time results, analyzed by Wald's Chi-square, showed significant statistical differences among all groups (p<0.001), indicating that the restorative strategy affected the time required for the restoration. A generalized estimating equation model statistical analysis, performed to compare postoperative sensitivity, showed that neither the restorative technique, the adhesive strategy nor the presentation mode of the bulk-fill composite affected the overall risk of postoperative sensitivity (4.06 [2.22-6.81]). The use of bulk-fill composite, presented in capsules or syringes, is less time consuming and does not increase the risk or intensity of postoperative sensitivity relative to the traditional incremental technique.

Objectives: This study evaluated the effect of the administration of pre-operative dexamethasone on tooth sensitivity stemming from in-office bleaching., Materials and Methods: A triple-blind, parallel-design, randomized clinical trial was conducted on 70 volunteers who received dexamethasone or placebo capsules. The drugs were administered in a protocol of three daily 8-mg doses of the drug, starting 48 h before the in-office bleaching treatment. Two bleaching sessions with 37.5% hydrogen peroxide gel were performed with a 1-week interval. Tooth sensitivity (TS) was recorded on visual analog scales (VAS) and numeric rating scales (NRS) in different periods up to 48 h after bleaching. The color evaluations were also performed. The absolute risk of TS and its intensity were evaluated by using Fisher's exact test. Comparisons of the TS intensity (NRS and VAS data) were performed by using the Mann-Whitney U test and a two-way repeated measures ANOVA and Tukey's test, respectively., Results: In both groups, a high risk of TS (Dexa 80% x Placebo 94%) was detected. No significant difference was observed in terms of TS intensity. A whitening of approximately 3 shade guide units of the VITA Classical was detected in both groups, which were statistically similar., Conclusions: It was concluded that the administration pre-operatively of dexamethasone, in the proposed protocol, does not reduce the incidence or intensity of bleaching-induced tooth sensitivity., Clinical Relevance: The use of dexamethasone drug before in-office bleaching treatment does not reduce incidence or intensity of tooth sensitivity., Clinical Trial Registration Number: NCT02956070.

The dental profession is still pursuing the most effective way to treat white-spot lesions in order to produce a sound and esthetically pleasing enamel surface. The aim of the present research was to evaluate in vitro the effects of a dentifrice with nanohydroxyapatite (nano-HAp) on the roughness, color, lightness, and brightness (gloss) of bovine enamel subjected to pH cycling. Twelve enamel discs prepared from bovine incisors were divided into 2 experimental groups: dentifrice with sodium fluoride (Colgate Total 12 Clean Mint) and dentifrice with nanoHAp (Megasonex). For 14 days, the specimens were subjected to 30 cycles of simulated brushing twice a day as well as to a pH cycling model (6 hours of demineralization and 18 hours of remineralization daily). The roughness, color, lightness, and brightness of all specimens were evaluated at baseline (immediately after specimen preparation) and after 7 and 14 days of treatment. A Tukey test demonstrated that there were no statistically significant differences in the effects of the dentifrices on any parameter after 7 days (P > 0.05). After 14 days, however, there was a statistically significant increase in mean roughness in the group brushed with fluoride dentifrice (P < 0.05). Thus, the nanoHAp containing dentifrice promoted less superficial roughness after 14 days, but both dentifrices were similar in relation to color variation, lightness, and brightness., Competing Interests: Disclaimer: The authors report no conflicts of interest pertaining to any of the products or companies discussed in this article.

In this in vitro study, 3 experiments were conducted to evaluate the influence of customizing the apical portion on the characteristics of fiber posts. In the first experiment, 4 fiber posts were submitted to different custom adaptations (no customization, industrial shaping tool, diamond bur, or paper disc) and were observed with a scanning electron microscope to evaluate the micromorphologic changes. In the second experiment, 60 posts of different sizes were divided into 6 groups (n = 10): 0 (No. 0.5), 1 (No. 1), 2 (No. 2), 3 (No. 3), 4 (No. 4), and 5 (paper disc-remodeled No. 4). The posts were submitted to a 3-point bending test. In the third experiment, the crowns of 20 extracted, healthy permanent human canines were removed, and the teeth were endodontically treated, embedded in acrylic resin, and divided into 2 groups (n = 10): I (control), No. 4 posts cemented into post spaces prepared with a No. 4 drill; and II (test), remodeled No. 4 posts cemented into root spaces prepared with No. 2 and 4 drills. The posts were cemented with self-adhesive dual resin cement, and the specimens received direct resin crowns. Fracture strength was measured with a universal testing machine at 45 degrees until fracture. Results were submitted to analysis of variance (P ≤ 0.05). Customization of fiber posts with diamond burs or paper discs produced acceptable micromorphologic changes. Custom adaptation of fiber posts reduced their flexural strength, which remained at acceptable values. Teeth restored with customized fiber posts had greater fracture strength than those restored with intact posts. The results of this study indicated that post remodeling is a safe means to facilitate adaptation to root walls and preserve tooth structure.

Gingival biotype is a clinical term used to describe the thickness of the gingiva. It has been classified as being thick or thin and may be related to the clinical outcome of root coverage procedures. This study evaluated the impact of gingival biotype on the clinical outcome of root coverage procedures following subepithelial connective tissue graft plus coronally positioned flap. A total of 19 patients, 10 with thin and 9 with thick gingival biotype, were treated for localized Miller Class I or II gingival recessions. After 6 months, 14 patients achieved complete root coverage, 7 from each group. The overall mean pooled root coverage rate was 90.93%. The thin biotype cases yielded a reduced mean root coverage of 88.51% compared with 93.63% for patients who had the thick biotype classification. Although the thin gingival biotype may impair the clinical outcome of root coverage procedures, this limitation does not appear to have a strong influence on the success of the root coverage therapy when subepithelial connective tissue graft was associated with the coronal positioning of the flap.

The objective of this in vitro study was to compare the microleakage of a flowable low-shrinkage-stress resin composite--in a Class II fatigue-loading design when used as a 4 mm dentin replacement--to a conventionally layered silorane-based resin composite. Eighty standardized 4 mm deep cavities, divided into 4 subgroups, were restored with the 2 tested materials. Half of the restorations were submitted to mechanical loading, and all of the restorations were prepared for microleakage evaluation. The evaluation of the marginal adaptation to dentin was performed with scanning electron microscopy. The results showed that both silorane-based composite groups had higher rates of microleakage in comparison to the low-shrinkage-stress resin composite groups.

The absence of interdental papillae can be a negative influence in aesthetics. Periodontal biotype (PB) is one of the factors that can possibly influence this relation and has to be considered in periodontal diagnosis and treatment planning. The objective of this study was to evaluate the influence of the periodontal biotype on the presence and absence of interdental papillae. Forty-seven patients were included in this transversal clinical study. The PB, presence and height of interdental papilla, loss of papillary height, and the distance between the base of the contact point and bone crest (CP-BC) were evaluated. The chi-square test was used to verify the significance level of the PB distribution frequency between groups. The Mann-Whitney test was used to compare the CP-BC measures between the different PB groups, and the correlation test was used to verify the relation between the CP-BC distance and the presence of papillae. The thin PB group presented a significantly higher presence of papillae (71.1%) than did the thick PB group (59.6%, P < 0.05). An inverse and proportional correlation between the CP-BC distance and the presence of papillae was found. The authors concluded that the PB influenced the presence and height of interdental papillae.

Dentinal surfaces prepared with air abrasion have considerably different characteristics from those prepared with conventional instruments. Different hybrid layer morphology and thickness occur, which can result in differences in the quality of restorations placed on dentinal surfaces prepared with a diamond bur compared to surfaces prepared using air abrasion. The objective of this study was to compare the hybrid layer thickness and morphology formed utilizing Scotchbond Multi-Purpose Plus (SBMP) on dentin prepared with a diamond bur in a high-speed handpiece and on dentin prepared using air abrasion. Flat dentin surfaces obtained from five human teeth were prepared using each method, then treated with the dentin adhesive system according to manufacturer's instructions. After a layer of composite was applied, specimens were sectioned, flattened, polished, and prepared for scanning electron microscopy. Ten different measurements of hybrid layer thickness were obtained along the bonded surface in each specimen. SBMP produced a 3.43 ± 0.75 µm hybrid layer in dentin prepared with diamond bur. This hybrid layer was regular and found consistently. In the air abrasion group, SBMP produced a 4.94 ± 1.28 µm hybrid layer, which was regular and found consistently. Statistical ANOVA (P = 0.05) indicated that there was a statistically significant difference between the groups. These data indicate that the air abrasion, within the parameters used in this study, provides a thick hybrid layer formation.

Dentinal surfaces prepared with an Er:YAG laser have distinctly different characteristics compared to those prepared with conventional instruments. The objective of this study was to evaluate the shear bond strength of a total-etch adhesive system and a self-etch adhesive system to dentin, prepared conventionally or with an Er:YAG laser. Specimens that were prepared with a diamond bur and treated with the total-etch adhesive showed the highest mean bond strength, followed by specimens prepared with the laser and treated with the total-etch adhesive, specimens prepared with a diamond bur and treated with the self-etch adhesive, and specimens prepared with the laser and treated with the self-etch adhesive, but there were no differences among the groups (P > 0.05). These data indicate that the tested adhesive systems promote similar shear bond strengths, whether the dentin is prepared with a diamond bur or an Er:YAG laser, and that an Er:YAG laser is a suitable cavity preparation method that promotes an adequate surface for a posterior adhesive procedure.

The objective of this study was to evaluate the effect of storage in deionized water at room temperature, for seven days and six months, on the flexural strength of a repaired photocured microhybrid composite resin, using different surface treatments. After each surface treatment, the adhesive interface was analyzed with a surface roughness tester. The flexural strength of samples from each group was determined by three-point bending in a testing machine at a crosshead speed of 0.5 mm/min with a 50 N load cell. Data were analyzed using ANOVA (p=0.0001) and compared with the Newman-Keuls multiple comparison test. It was verified that flexural strength of the unrepaired specimens, after both seven days and six months, was similar (p>0.05) and was in accordance with ISO specifications (minimum of 50 MPa), with values ranging from 52-63 MPa. The authors concluded that the use of an unfilled resin agent is necessary prior to the repair to increase the adhesive strength. Further, the use of a silane agent prior to use of the unfilled resin agent is unnecessary, since it does not increase the adhesive strength.

This study compared the thickness of the hybrid layer formed using Scotchbond Multi-Purpose Plus, Single Bond 2, Prime & Bond 2.1 and Xeno III on a dentin surface prepared with a diamond bur in a high speed handpiece or prepared with an Er:YAG laser used with two parameters of pulse energy (200 and 400 mJ) and two parameters of frequency (4 and 6 Hz). Flat dentin surfaces obtained from 20 human third molars were treated with the two methods and were then prepared with the dentin adhesive systems according to the manufacturers' instructions. After a layer of composite was applied, the specimens were sectioned, flattened, polished and prepared for Scanning Electronic Microscopy observation. Five different measurements of the hybrid layer thickness were obtained along the bonded surface in each specimen. The results were statistically analyzed using Analysis of Variance and Student-Newman-Keuls tests (p < or = 0.05). When analyzing the hybrid layer thickness and comparing the cavity preparation method, four groups were formed: Group I (diamond bur) > Group II (Laser 200 mJ/4 Hz) = Group III (Laser 200 mJ/6 Hz) > Group IV (Laser 400 mJ/4 Hz) > Group V (Laser 400 mJ/6 Hz). When comparing the dentin adhesive systems, there were no statistically significant differences. These results showed that the four tested dentin adhesive systems produced a 2.90 +/- 1.71 microm hybrid layer in dentin prepared with a diamond bur. This hybrid layer was regular and routinely found. In the laser groups, the dentin adhesive systems produced hybrid layers ranging from 0.41 +/- 1.00 microm to 2.06 +/- 2.49 microm, which were very irregular and not routinely found. It was also concluded that the Er:YAG laser, with the parameters used in this experiment, has a negative influence on the formation of a hybrid layer and cavity preparation methods influence formation of the hybrid layer.