Influence of thermal and mechanical fatigue on the shear bond strength of different all-ceramic systems.

BACKGROUND: To evaluate the influence of thermal and mechanical fatigue on the shear bond strength of different all-ceramic cores and veneering porcelain interfaces. MATERIAL AND METHODS: All-ceramic systems tested were lithium disilicate and zirconia veneered by layering technique. Sixty specimens (n=20) were subjected to shear bond strength. Ten of them were thermal and mechanical cycled. Fracture analysis was performed with stereomicroscopy and scanning electron microscopy. Energy dispersive X-ray spectroscopy analysis was performed across core/veneer interfaces. RESULTS: Thermal and mechanical cycling did not influence on bond strength. However, there was significant difference among systems (<0.01). CoCr group presented the highest values, followed by lithium disilicate, and zirconia. Failure modes were predominantly adhesive for CoCr, cohesive in core for lithium disilicate, and cohesive in veneer for zirconia. Energy dispersive X-ray showed interaction zone for CoCr and lithium disilicate groups and was inconclusive for zirconia. Fatigue had no influence on bond strength of groups tested. CONCLUSIONS: The results suggest that there is a chemical bond between core and veneer materials for CoCr and lithium disilicate groups. Key words:Ceramics, electron microscopy, fatigue, mechanical stress, shear bond strength.

Does hybridized dentin affect bond strength of self-adhesive resin cement?

BACKGROUND: Evaluate the influence of different hybridization bonding techniques of a self-adhesive resin cement. MATERIAL AND METHODS: 30 human health molars were divided into six groups (n=10). The specimens received three longitudinal sections, allowing insertion of central cuts in PVC matrices. Each group received a different dentin pretreatment according to the manufacturer's recommendations, except the control group (G1), as follows. G2 - a 3-step total-etch adhesive system (Optibond™ FL, Kerr); G3 - a 3-step total-etch adhesive system (Adper™ Scotchbond™ Multi-Purpose, 3M ESPE); G4 - a 2-step total-etch adhesive system (Adper™ Single Bond 2, 3M ESPE); G5 - a single-step self-etching system (Bond Force, Tokuyama); and G6 - universal bonding system (Single Bond Universal, 3M ESPE). Then, cylinders made of self-adhesive resin cement with polypropylene matrix was cemented in all groups (RelyX U200, 3M ESPE). Bond strength was assessed by submitting the specimens to micro-shear test and was characterized according to the fracture pattern observed through optical microscopy. RESULTS: The results were submitted to the Kruskal-Wallis test, which indicated a statistically significant difference between the groups (p=0.04), and Tukey's multiple comparisons, which indicated a statistically significant difference between G1 and G3 (p<0.05). The microscopic analysis revealed a high prevalence of adhesive failures, followed by mixed fractures, and cohesive failures in the dentin. CONCLUSIONS: The use of a previous dentin hybridization protocol is able to increase adhesive bonding resistance of self-adhesive resin cement, especially when used Adper™ Scotchbond™ Multi-Purpose system. Key words:Bonding, self-adhesive resin cement, adhesive systems, microshear.

Effect of silorane-based adhesive system on bond strength between composite and dentin substrate.

CONTEXT: The complexities of the oral environment, the dentin substrate, and the different bond and composite resin systems represent a challenge to the maintenance of reasonable bond between the composite resin and the tooth structure. AIMS: To evaluate the effect of the adhesive system on bond strength between silorane-based composite resin and dentin. MATERIALS AND METHODS: Fourteen human molars extracted were selected and vertically cut into 3 dentin fragments, randomly divided among the experimental groups and restored with Z250 and P90 composite resin using different adhesive protocols (Adper Single Bond 2, Silorano primer, Adper SE Plus, and Scotchbond Multiuse). Two composite resin cylinders were built up on each dentin surface (n = 10) and subjected to a micro-shear bond strength test. STATISTICAL ANALYSIS USED: Kruskal-Wallis one-way analysis of variance and Tukey test (P = 0.05). RESULTS: According to the results, Kruskal-Wallis test evidenced at least one statistical significant difference (P = 0.001). The Tukey test showed statistically significant differences among the group (P < 0.05). Group PSM8 (P90 + SM) showed statically significant higher results when compared with groups PSP4 (P90 + SP), PSB2 (P90 + SB), and ZSE5 (Z250 + SE). CONCLUSION: The results evidenced that the monomer of the adhesive system has an effect on bond strength between the composite resin and dentin.

The effect of post material on the characteristic strength of fatigued endodontically treated teeth.

STATEMENT OF PROBLEM: The biomechanical properties of post systems may become more important as the amount of remaining tooth structure decreases, thus different materials may influence the characteristic strength of fatigued endodontically treated teeth. PURPOSE: The purpose of this study was to assess the characteristic strength and probability of survival of endodontically treated teeth restored with different intraradicular post systems. MATERIAL AND METHODS: Forty human maxillary canines with similar root lengths were randomly divided into 4 groups (n=10): cast post and core, stainless-steel prefabricated post, carbon-fiber post, and glass-fiber post. Cores and metallic crowns were fabricated for all specimens. Restored teeth were exposed to mechanical fatigue (250,000 cycles) in a controlled chewing simulator. Each intact specimen was mounted in a special device and aligned at a 45-degree angle to the long axis of the tooth. A universal testing machine was used to apply a static load at a crosshead speed of 0.5 mm/min until specimen failure. The maximum value was recorded in newtons (N). Probability Weibull curves (2-sided 90% confidence bounds) were calculated for each group, and a probability of survival as a function of load at failure was plotted for the groups. RESULTS: A significantly higher characteristic strength was observed for groups carbon-fiber post (755.82 N) and cast post and core (750.6 N) (P<.05) compared with glass-fiber post (461.35 N) and stainless-steel prefabricated post (524.78 N) groups. All the roots in the cast post and core group demonstrated catastrophic fracture, whereas the remaining groups had no root fractures. CONCLUSIONS: Prefabricated posts made of glass fiber and stainless steel showed significantly lower characteristic strength and probability of survival than cast post and core, whereas crowns with carbon-fiber posts presented a single load similar to the fracture values of cast posts.

A method of assessing the effectiveness of the friction fit interface by measuring reverse torque.

STATEMENT OF THE PROBLEM: The connection between abutments and implants is fundamental to successful prosthetic rehabilitation, and the loosening or fracture of the parts are undesirable outcomes. PURPOSE: The purpose of this study was to measure the reverse torque values of 2 different types of Morse taper implants. MATERIAL AND METHODS: Ten Morse taper implants were used, with their respective abutments. They were divided into 2 groups (n = 5): Group DH, implant interface with a double hexagon and Group OI, octagonal implant interface. Each abutment received 2 consecutive insertion torques (32 Ncm) at a 10-minute interval and 1 reverse torque after 5 minutes. The data were analyzed with the Student t test (α= .05). RESULTS: The Student t test demonstrated no significant differences between the values of the insertion and removal torques of the 2 groups (Group DH, P= .22 and Group OI, P= .42) or the removal torque values of the groups (P= .12). CONCLUSION: The results suggest that the strength required to loosen the abutment screws as measured by reverse torque is similar for both a double hexagon interface (DH) and an octagonal interface (OI).

The influence of different cements on the pull-out bond strength of fiber posts.

STATEMENT OF PROBLEM: Glass fiber posts are commonly used to provide adequate support and retention for the restoration of endodontically treated teeth, but their resistance to dislodgement depends on their adhesion to root dentin. PURPOSE: The purpose of this study was to assess the effect of cement type on the pull-out bond strength of fiber posts. MATERIAL AND METHODS: Seventy maxillary canines were endodontically treated and then divided into 7 groups according to the cement used for fiber post cementation as follows (n = 10): RelyX Unicem, BisCem, RelyX Luting 2, RelyX ARC, Panavia F, Enforce, and Allcem. The specimens were subjected to a pull-out bond strength test in a universal testing machine at a crosshead speed of 0.5 mm/min. The results, in newtons, were analyzed with 1-way ANOVA and the Tukey post hoc test (α = .05). RESULTS: RelyX Unicem (472.3 ± 8.9 N), BisCem (506.6 ± 9.2 N), RelyX ARC (498.0 ± 8.2 N), Panavia F (502.3 ± 7.0 N), and Allcem (470.0 ± 11.3 N) presented significantly higher bond strength than RelyX Luting 2 (241.8 ± 9.70 N) and Enforce (309.5 ± 6.3 N) cements (mean ± SD; P < .05). CONCLUSIONS: Except for Enforce, all resin cements produced pull-out bond strength values twice that of resin modified glass ionomer cement. However, all cements promoted adequate retention to fiber posts to withstand functional loads.

Thermo and mechanical cycling and veneering method do not influence Y-TZP core/veneer interface bond strength.

OBJECTIVES: The purpose of this study was to evaluate the influence of thermal and mechanical cycling and veneering technique on the shear bond strength of Y-TZP (yttrium oxide partially stabilized tetragonal zirconia polycrystal) core-veneer interfaces. MATERIALS AND METHODS: Cylindrical Y-TZP specimens were veneered either by layering (n=20) or by pressing technique (n=20). A metal ceramic group (CoCr) was used as control (n=20). Ten specimens for each group were thermal and mechanical cycled and then all samples were subjected to shear bond strength in a universal testing machine with a 0.5mm/min crosshead speed. Mean shear bond strength (MPa) was analysed with a 2-way analysis of variance and Tukey's test (p<0.05). Failure mode was determined using stereomicroscopy and scanning electron microscopy (SEM). RESULTS: Thermal and mechanical cycling had no influence on the shear bond strength for all groups. The CoCr group presented the highest bond strength value (p<0.05) (34.72 ± 7.05 MPa). There was no significant difference between Y-TZP veneered by layering (22.46 ± 2.08 MPa) or pressing (23.58 ± 2.1 MPa) technique. Failure modes were predominantly adhesive for CoCr group, and cohesive within veneer for Y-TZP groups. CONCLUSIONS: Thermal and mechanical cycling, as well as the veneering technique does not affect Y-TZP core-veneer bond strength. CLINICAL SIGNIFICANCE: Different methods of veneering Y-TZP restorations would not influence the clinical performance of the core/veneer interfaces.

Tensile resistance of mineralized and demineralized rat bones in different regions (calvarial and femur).

The aim of this study was to evaluate the tensile resistance of mineralized and demineralized bones. Twelve mice were used. Specimens were collected and divided into groups 1 and 2, mineralized and demineralized calvarial bone, and groups 3 and 4, mineralized and demineralized femoral bone. There was not a statistically significant difference (analysis of variance) between the regions; however, when comparing the demineralized and mineralized groups, a statistically significant difference (Student test) for the mineralized group was noticed.

Gingival recession in individuals with cleft lip and palate: prevalence and severity.

OBJECTIVE: To analyze the prevalence and severity of gingival recession in individuals with cleft lip and alveolus with or without cleft palate. DESIGN: Cross-sectional. SETTING: Tertiary referral hospital. PARTICIPANTS: A total of 400 individuals with cleft lip and alveolus with or without cleft palate, aged 15 to 49 years, without any previous periodontal treatment. MAIN OUTCOME MEASURES: Gingival recession was evaluated by measuring the distance from the cementoenamel junction to the most coronal point on the gingival margin, analyzing the prevalence and scoring its severity as mild (<3 mm), moderate (3 to 4 mm), or severe (4 mm). The prevalence and severity of gingival recession was compared between sextant 2 (cleft sextant) and the mean of the other sextants (1, 3, 4, 5, and 6: noncleft sextants). The relationship between gingival recession in the cleft area and gender was evaluated and data were analyzed statistically. The correlation between gingival recession and age was assessed also. RESULTS: There was no statistically significant gender difference in gingival recession. The prevalence and severity of gingival recession increased with age, and most of the affected teeth were premolars and molars. The cleft area did not present a higher prevalence and severity of gingival recession. CONCLUSIONS: Individuals with cleft lip and alveolus with or without cleft palate presented the same prevalence and severity of gingival recession compared with other populations. The area adjacent to the cleft (sextant 2) did not show greater risk of gingival recession than other areas (sextants 1, 3, 4, 5, and 6).

Effect of carbon and glass fiber posts on the flexural strength and modulus of elasticity of a composite resin.

The aim of this study was to evaluate the effect of prefabricated fiber posts on the flexural strength and modulus of elasticity of a composite resin. Thirty bar-shaped specimens measuring 25 x 2.0 x 2.0 mm were made, containing posts that were 1.3 mm in diameter and 20 mm long. Each group contained 10 specimens: Group 1, resin without post; Group 2, resin with carbon fiber post; Group 3, resin with glass fiber post. The samples were immersed in water at 37 degrees C until the three-point loading test was performed at a speed of 1.0 mm/minute. The results were statistically analyzed by ANOVA and Tukey's test (P = 0.05). Both fiber posts were similar in strength and both were stronger than the control. Group 3 obtained a higher mean modulus of elasticity than Groups 1 and 2, which were similar. The results of this study demonstrated that the presence of a fiber post significantly raised flexural strength values and the glass fiber post significantly increased the modulus of elasticity of the evaluated composite resin.

Correlation between margin fit and microleakage in complete crowns cemented with three luting agents.

UNLABELLED: Microleakage can be related to margin misfit. Also, traditional microleakage techniques are time-consuming. This study evaluated the existence of correlation between in vitro margin fit and a new microleakage technique for complete crowns cemented with 3 different luting agents. Thirty human premolars were prepared for full-coverage crowns with a convergence angle of 6 degrees, chamfer margin of 1.2 mm circumferentially, and occlusal reduction of 1.5 mm. Ni-Cr cast crowns were cemented with either zinc phosphate (ZP) (S.S. White), resin-modified glass-ionomer (RMGI) (Rely X Luting Cement) or a resin-based luting agent (RC) (Enforce). Margin fit (seating discrepancy and margin gap) was evaluated according to criteria in the literature under microscope with 0.001 mm accuracy. After thermal cycling, crowns were longitudinally sectioned and microleakage scores at tooth-cement interface were obtained and recorded at x100 magnification. Margin fit parameters were compared with the one-way ANOVA test and microleakage scores with Kruskal-Wallis and Dunn's tests (alpha=0.05). Correlation between margin fit and microleakage was analyzed with the Spearman's test (alpha=0.05). Seating discrepancy and marginal gap values ranged from 81.82 microm to 137.22 microm (p=0.117), and from 75.42 microm to 78.49 microm (p=0.940), respectively. Marginal microleakage scores were ZP=3.02, RMGI=0.35 and RC=0.12 (p<0.001), with no differences between RMGI and RC scores. The correlation coefficient values ranged from -0.27 to 0.30 (p>0.05). CONCLUSION: Margin fit parameters and microleakage showed no strong correlations; cast crowns cemented with RMGI and RC had lower microleakage scores than ZP cement.

Palpation of the lateral pterygoid area in the myofascial pain diagnosis.

OBJECTIVES: To evaluate the diagnostic value of intraoral palpation at the lateral pterygoid (LP) area as part of the physical examination to detect myofascial pain, according to modified research diagnostic criteria for temporomandibular disorders. STUDY DESIGN: Forty-four women composed the myofascial pain group, and 33 symptom-free age-matched were the control group. One examiner calibrated and blinded to group distribution performed 2 intraoral bilateral palpations of the lateral pterygoid. RESULTS: The LP area palpation showed sensitivity and specificity values of 79.55% and 77.27%, respectively, and positive and negative likelihood ratios of 3.50 and 0.26, respectively. CONCLUSIONS: Palpation at the LP area did not reach acceptable values of specificity, and care must be taken when judging positive response to this procedure.

Fracture resistance of weakened roots restored with composite resin and glass fiber post.

This study evaluated the fracture resistance of weakened roots restored with glass fiber posts, composite resin cores and complete metal crowns. Thirty maxillary canines were randomly divided into 3 groups of 10 teeth each: teeth without weakened roots (control); teeth with partially weakened roots (PWR) and teeth with and largely weakened roots (LWR). The control group was restored with glass fiber posts and a composite resin core. Teeth in the PWR and LWR groups were flared internally to standardized dimensions in order to simulate root weakness. Thereafter, the roots were partially filled with composite resin and restored in the same way as in the control group. The specimens were exposed to 250,000 cycles in a controlled chewing simulator. All intact specimens were subjected to a static load (N) in a universal testing machine at 45 degrees to the long axis of the tooth until failure. Data were analyzed by one-way ANOVA and Dunnett's test for multiple comparisons (p=0.05). There were statistically significant difference differences (p<0.01) among the groups (control group = 566.73 N; PWR = 409.64 N; and LWR = 410.91 N), with significantly higher fracture strength for the control group. There was no statistically significant difference (p>0.05) between the weakened groups. The results of this study showed that thicker root dentin walls significantly increase the fracture resistance of endodontically treated teeth.

Fracture strength of teeth with flared root canals restored with glass fibre posts.

OBJECTIVE: To investigate the fracture strength and pattern of failure of teeth with weakened roots reconstructed by different procedures. METHODS: In an in vitro study root posts were placed in 50 endodontically treated canines, divided into 5 groups (n=10) as follows: cast metallic post; glass fibre post with smaller diameter than the root canal; glass fibre post with smaller diameter than the root canal + glass fibre strips; glass fibre post with smaller diameter than the root canal + accessory glass fibre posts; anatomical post (glass fibre post with smaller diameter than the root canal, relined with low viscosity composite resin). Posts were luted with resin cement and the coronal portion of posts was constructed with composite resin. Metallic crowns were cemented on the posts. Specimens were submitted to compressive load in a universal testing machine. Fracture strength values of each group were compared. RESULTS: Fracture strength values were for Groups 1-5 respectively: 1087.06; 745.69; 775.41; 920.64; 876.12kgf, with significant differences between Groups 1 and 2 and between Groups 1 and 3 (p<0.05). Observed patterns of fracture were: Group 1 - 100% of roots fractured; Groups 2 and 4 - variable fracture modes; Group 3 - 60% of fractures occurred in the cervical root third; Group 5 - 50% of failures occurred in the coronal portion of the post. CONCLUSIONS: The fracture strength of teeth with cast metallic posts, teeth with anatomical posts or teeth with glass fibre posts combined with accessory posts was similar. All teeth restored with cast metallic posts presented fractures and were unfavourable to maintenance of the remaining tooth structure. Teeth with fibre posts (Groups 2 to 5) presented variable fracture modes; however, the maximum percentage of unfavourable fractures was 30%.

Tensile bond strength of glass fiber posts luted with different cements.

Proper selection of the luting agent is fundamental to avoid failure due to lack of retention in post-retained crowns. The objective of this study was to investigate the tensile bond strength and failure mode of glass fiber posts luted with different cements. Glass fiber posts were luted in 40 mandibular premolars, divided into 4 groups (n = 10): Group 1--resin-modified glass ionomer RelyX Luting; Group 2--resin-modified glass ionomer Fuji Plus; Group 3--resin cement RelyX ARC; Group 4--resin cement Enforce. Specimens were assessed by tensile strength testing and light microscopy analysis for observation of failure mode. The tensile bond strength values of each group were compared by ANOVA and Tukey test. The significance level was set at 5%. The failure modes were described as percentages. The following tensile strength values were obtained: Group 1--247.6 N; Group 2--256.7 N; Group 3--502.1 N; Group 4--477.3 N. There was no statistically significant difference between Groups 1 and 2 or between Groups 3 and 4, yet the resin cements presented significantly higher tensile bond strength values than those presented by the glass ionomer cements. Group 1 displayed 70% of cohesive failures, whereas Groups 2, 3 and 4 exhibited 70% to 80% of adhesive failures at the dentin-cement interface. We concluded that resin cements and glass ionomer cements are able to provide clinically sufficient retention of glass fiber posts, and that glass ionomer cements may be especially indicated when the application of adhesive techniques is difficult.

Comparative study of ceramic-to-metal bonding.

Dentists and technicians have used dental ceramics associated with different types of alloys without taking into account the characteristics of compatibility of these materials. Knowing the properties of the alloy and ceramic used in metal/ceramic restorations is a key factor for treatment success. The purpose of this study was to evaluate the bond strength of a palladium-silver alloy (Pors-on 4) to 3 ceramics (Ceramco, Noritake and Vita VMK-68) using shear forces at the metal-ceramic interface. A stainless steel cylindrical matrix was used for preparation of the metal dies, application of ceramic and shear strength testing. Thirty palladium-silver alloy cylinders received two layers of opaque and two layers of body porcelain, and shear tests were performed in a universal testing machine at a cross-head speed of 0.5 mm/min. Shear bond strength means (in MPa) were: 28.21(Ceramco), 28.96 (Noritake) and 24.11 (Vita VMK-68). One-way ANOVA did not show statistically significant differences (p>0.05) among the materials. The results of this study indicate that the three evaluated ceramic systems are suitable to be used in combination with the tested palladium-silver alloy.

Assessment of the prevalence index on signs of combination syndrome in patients treated at Bauru School of Dentistry, University of Sao Paulo.

A group of destructive changes occurring in jaws in patients with maxillary complete dentures and mandibular removable partial dentures (bilaterally) has been described in the literature as the combination syndrome. However, this condition is not clinically observed in all patients. The aim of this study was to establish the prevalence index on signs of combination syndrome and to verify whether these changes also occurred in patients rehabilitated with a mandibular removable partial denture (unilaterally). Sample was composed of 44 patients, completely edentulous in the maxilla. Thirty-two patients had a Kennedy Class I removable partial denture and 12 a Kennedy Class II. Three major alterations were observed in 20.5% of the studied population. Nevertheless, these changes were present only in 25% of patients with Kennedy Class I removable partial denture. Based on the findings of this study, it can be concluded that patients with Kennedy Class II removable partial denture do not have similar signs that lead to the combination syndrome's condition.

Comparison of the fracture resistance of endodontically treated teeth restored with prefabricated posts and composite resin cores with different post lengths.

OBJECTIVE: This study evaluated the fracture strengths of endodontically treated teeth restored with prefabricated posts with different post lengths. MATERIAL AND METHODS: Thirty freshly extracted canines were endodontically treated. They were randomly divided into groups of 10 teeth and prepared according to 3 experimental protocols, as follows; Group 1/3 PP: teeth restored with prefabricated post and composite resin core (Z250) with post length of 5.0mm; Group 1/2 PP and Group 2/3 PP: teeth restored with prefabricated post and composite resin core (Z250) with different combinations of post length of 7.5mm and 10mm, respectively. All teeth were restored with full metal crowns. The fracture resistance (N) was measured in a universal testing machine (crosshead speed 0.5mm/min) at 45 degrees to the tooth long axis until failure. Data were analyzed by one-way analysis of variance (alpha=.05). RESULTS: The one-way analysis of variance demonstrated no significant difference among the different post lengths (P>.05) (Groups 1/3 PP = 405.4 N, 1/2 PP = 395.6 N, 2/3 PP = 393.8 N). Failures occurred mainly due to core fracture. CONCLUSIONS: The results of this study showed that an increased post length in teeth restored with prefabricated posts did not significantly increase the fracture resistance of endodontically treated teeth.

Influence of the final temperature of investment healting on the tensile strength and Vickers hardness of CP Ti and Ti-6Al-4V alloy.

The aim of the work was to evaluate the influence of the temperature of investment healting on the tensile strength and Vickers hardness of CP Ti and Ti-6Al-4V alloy casting. Were obtained for the tensile strength test dumbbell rods that were invested in the Rematitan Plus investment and casting in the Discovery machine cast. Thirty specimens were obtained, fifteen to the CP Titanium and fifteen to the Ti-6Al-4V alloy, five samples to each an of the three temperatures of investment: 430 degrees C (control group), 480 degrees C and 530 degrees C. The tensile test was measured by means of a universal testing machine, MTS model 810, at a strain of 1.0 mm/min. After the tensile strength test the specimens were sectioned, embedded and polished to hardness measurements, using a Vickers tester, Micromet 2100. The means values to tensile tests to the temperatures 430 degrees C, 480 and 530: CP Ti (486.1 - 501.16 - 498.14 -mean 495.30 MPa) and Ti-6Al-4V alloy (961.33 - 958.26 - 1005.80 - mean 975.13 MPa) while for the Vickers hardness the values were (198.06, 197.85, 202.58 - mean 199.50) and (352.95, 339.36, 344.76 - mean 345.69), respectively. The values were submitted to Analysis of Variance (ANOVA) and Tukey Test that indicate differences significant only between the materials, but not between the temperature, for both the materials. It was concluded that increase of the temperature of investment its not chance the tensile strength and the Vickers hardness of the CP Titanium and Ti-6Al-4V alloy.

Surgical crown lengthening: a 12-month study - radiographic results.

OBJECTIVE: The purpose of this study was to perform a radiographic follow-up evaluation after a 12-month healing period, following crown lengthening surgery. MATERIAL AND METHODS: Twenty-three periodontally healthy subjects (mean age 32.5 years) that required crown lengthening surgery in premolars were recruited. In a total of 30 premolars, full thickness flaps, osseous resection, and flap suturing were performed. The restorative margin was defined in the pre-surgical phase and maintained unaltered during the healing period, serving as a reference point. Standardized bitewing radiographs were taken before and after osseous reduction, and at 2, 3, 6, and 12-month healing periods. RESULTS: Intact lamina dura was observed at both mesial and distal alveolar crests only from the 3rd month. At 12-months, all alveolar crests presented lamina dura. The overall mean distance from the restorative margin to the alveolar crest achieved after osseous resection was 3.28+/-0.87 mm at mesial and 2.81+/-0.51 mm at distal sites. No significant radiographic changes in the bone crest were observed during a 12-month healing period. CONCLUSION: The findings of this study suggest that the radiographic proximal bone level observed on bitewing radiographs following crown lengthening surgery can be used as a reference to predict the future level of the healed alveolar crest.