Biomedical subjects

Simone Grandini

Publications and source records attributed to Simone Grandini.

At least 19 recordsLinked to original sources

PubMed2006

Immediate and 24-hour evaluation of the interfacial strengths of fiber posts.

This study examined the contribution of testing time on the interfacial strengths of fiber posts to radicular dentin. Twenty-five fiber posts were luted to root segments with resin cements and a zinc phosphate cement. Immediately upon setting of the materials, the roots were sectioned into slices and randomly divided into two subgroups, depending on testing time (immediate vs. 24-hours), for push-out test. The results showed an improvement on the interfacial strength after 24 hours of storage. When data were pooled for each cement, the interfacial strengths (MPa) were: Optibond Solo Plus/Nexus: 10.3+/-3.8a; zinc phosphate cement: 10.1+/-2.7a; Multilink: 9.6+/-3.8ab; RelyX Unicem: 7.1+/-4.9bc; AllBond 2/Duolink: 6.7+/-3.5c (groups with same superscript letter were not statistically significant). It is concluded that bond strength can increase during the first 24 hours and that the interfacial strength is predominantly contributed by frictional retention.

Analysis of Variance↗

PubMed2006

Reduction in antimicrobial substantivity of MTAD after initial sodium hypochlorite irrigation.

Potential intrinsic tetracycline staining of intraradicular dentin has been observed when BioPure MTAD was employed as the final irrigant after initial rinsing with NaOCl. This study examined the effect of NaOCl-MTAD interaction on the antimicrobial substantivity of MTAD in dentin. Dentin cores previously irrigated with either MTAD, or in conjunction with 1.3% NaOCl as an initial irrigant were placed on blood agar plates inoculated with Escherichia faecalis at 10(5) cfu/ml. Dentin cores irrigated with 1.3% NaOCl only, and autoclaved dentin disks were used as the respective positive and negative controls. After anaerobic incubation, the mean diameter of bacterial inhibition zones formed around the MTAD group was significantly larger than the NaOCl/MTAD group, which, in turn, was not significantly different from the NaOCl positive control. Oxidation of MTAD by NaOCl resulted in the partial loss of antimicrobial substantivity in a manner similar to the peroxidation of tetracycline by reactive oxygen species.

Anti-Bacterial Agents↗

PubMed2006

Effect of dentin adhesives used as sealers and provisional cementation on bond strength of a resin cement to dentin.

PURPOSE: To evaluate the effects of dentin adhesives employed as resin sealers and provisional cementation on the bond strengths of a resin cement to dentin. METHODS: A two-step etch-and-rinse adhesive (Excite DSC--Group 1) and two-step self-etch adhesive (AdheSE--Group 2) were applied to exposed dentin surfaces prepared from human molars (N=4). Water was used instead of a resin sealer in control Groups 3 and 4. A eugenol-free provisional cement (except for Group 4) was applied to the treated surfaces. After storing in distilled water for 1 week, the provisional cement was removed and cylindrical composite blocks were luted with a resin cement (Variolink II). 0.9 x 0.9 mm sticks were produced from these luted specimens for microtensile bond testing and SEM examination. RESULTS: One-way ANOVA revealed that neither the resin sealer nor the temporary eugenol-free cement had a negative effect on the final bond strength (P> 0.05). Mixed failures were predominantly identified from SEM.

Acrylic Resins↗

PubMed2006

Whitening effect by stain inhibition from a chewing gum with sodium hexametaphosphate in a controlled twelve-week single-blind trial.

OBJECTIVE: A twelve-week clinical study was conducted to assess the effect of a chewing gum containing sodium hexametaphosphate (4%) on the inhibition of stain formation. METHODOLOGY: Fifty-four subjects were entered and completed all aspects of the study. Twenty-seven of the subjects were smokers, and the other half did not smoke. Subjects were randomly assigned to the test gum or no-gum group. Each participant received a full oral prophylaxis at the beginning of each period of observation. Those chewing the test gum agreed to chew four times a day, for five minutes each time, over twelve weeks. Those assigned to the no-gum group agreed not to chew any gum. After twelve weeks, participants were scored for stain deposits (Lobene Index), received a second oral prophylaxis, and joined the alternate group in this cross-over format. At the end of the twenty-fourth week, all subjects were again scored for stain deposits and the study was completed. In order to enhance stain formation during the entire 24-week study period, all participants received a supply of a chlorhexidine (0.12%) dentifrice without anionic agents to use three times a day. Stain levels were scored by the same examiner for all measurements and recorded on computer. The examiner was blinded to all treatment assignments. RESULTS: There were no reported problems associated with the chewing gum. The Lobene Index mean score for stain extent was 0.54 +/- 0.36) in the test-gum group and 0.81 +/- 0.47) for the no-gum group. The difference between the mean scores was highly significant with paired sample t-test (p < 0.001). Mean stain intensity was 0.57 +/- 0.38) in the test group and 0.95 (+/- 0.72) in the control group, with a statistically significant difference at p < 0.01. CONCLUSION: The results indicated that chewing gum containing sodium hexametaphosphate reduced induced stain formation by 33% compared to a no-gum treatment.

Adolescent↗

PubMed2005

Fatigue resistance and structural characteristics of fiber posts: three-point bending test and SEM evaluation.

OBJECTIVES: The aim of the present study was to assess the fatigue resistance of different types of fiber posts, and to observe their ultrastructure through scanning electron microscopy (SEM) before and after undergoing the fatigue test. METHODS: Eight types of fiber posts were selected for this study. Easypost (Group 1), Para Post Fiber White (Group 2), FibreKor (Group 3), Ghimas White (Group 4), DT Light-Post radiopaque (Group 5), FRC Postec (Group 6), Luscent Anchors (Group 7), Snowpost (Group 8). Ten out of fifteen posts in each group were used for the fatigue test, and the other five were processed for SEM. A three-point bending machine, loading at an angle of 90 degrees and a frequency of 3 Hz was employed for fatigue testing. The test was carried out until two million cycles were completed or until fracturing of the post. SEM evaluation was performed using a three-step scale method to assess the fiber/resin ratio and fiber dimension. RESULTS: The fatigue test showed statistically significant differences among the different posts. Groups 5 and 6 performed better than all the other groups, withstanding practically all the stipulated number of load cycles. All the other posts fractured before the end of the test. SEM observations of the surface integrity of the fiber posts showed that Groups 4-6 obtained better scores for both longitudinal sections and cross-sections. SIGNIFICANCE: There was a large variation in the response of different kinds of fiber posts a fatigue resistance test. The absence of correlation between results of fatigue testing and parameters of structural integrity suggests that the latter mostly reflect random variations in the fiber post manufacturing process.

Composite Resins↗

PubMed2005

Scanning electron microscopic evaluation of fiber post-resin core units built up with different resin composites.

PURPOSE: To microscopically evaluate the structural characteristics of post-and-core units made of a fiber post and of different types of resin-based composites used as core materials. METHODS: 55 endodontically treated human maxillary incisors were prepared for receiving a fiber post (AEsthetic Post Plus). One-Step and C&B resin cement were used for luting the post. Samples were randomly divided into 11 groups. Eleven different composite materials were selected to build-up the abutment. The materials on trial were: Group 1: Z100; Group 2: Light-Core; Group 3: Lumiglass; Group 4: Gradia Direct; Group 5: Build-It!; Group 6: Tetric Ceram; Group 7: Biscore self-curing; Group 8: Unifil Flow; Group 9: Definite Flow; Group 10: Tetric Flow; Group 11: AEliteFlo. All the post-and-core specimens were cut perpendicularly to their long axis and processed for SEM observations. The presence of voids/bubbles within the resin abutment and of defects at the interface between the post surface and the core material was scored. These aspects were quantified with reference to a predefined index. The differences among the scores were tested for statistical significance (P< 0.05). RESULTS: Cores built up with flowable composites showed the highest integrity and the best adaptation onto the post.

Analysis of Variance↗

PubMed2005

In vitro evaluation of wall-to-wall adaptation of a self-adhesive resin cement used for luting gold and ceramic inlays.

PURPOSE: This in vitro study evaluated the wall-to-wall adaptation of a new self-adhesive resin-based cement (RelyX Unicem) in comparison with that of other cements when luting gold and porcelain inlays in standardized Class II cavities in extracted teeth. MATERIALS AND METHODS: In each experimental group (n = 10), a different combination of inlay and luting material was tested. Group 1: Porcelain Empress II (Ell) and RelyX Unicem (U); group 2: Ell and resin-based cement Variolink II in combination with primer and bonding Excite DSC; group 3: gold inlays (G) and U; group 4: G and Harvard zinc-oxy-phosphate cement; group 4: G and glass-ionomer cement Fuji Cem. After storage and thermocycling, microleakage testing was carried out and dye penetration was examined at the occlusal and cervical margins of each inlay. The differences in microleakage score were tested for statistical significance first comparing all groups, then pooling the groups for inlay material (Kruskal-Wallis nonparametric ANOVA and Mann-Whitney U test, p < 0.05). SEM observations of the tooth/cement/restoration interfaces were also made in each group. RESULTS: Harvard cement had the highest microleakage. The sealing ability exhibited by RelyX Unicem was satisfactory with both gold and porcelain inlays, and comparable to that of Fuji Cem and Variolink II. CONCLUSION: RelyX Unicem achieved an adequate seal on both enamel and dentin when used to lute in vitro gold and porcelain inlays.

Dental Cavity Preparation↗

PubMed2005

SEM evaluation of the cement layer thickness after luting two different posts.

PURPOSE: To verify with SEM the cement layer thickness and uniformity of resin-relined translucent fiber posts (anatomic posts) and standard translucent fiber posts. MATERIALS AND METHODS: On 20 extracted maxillary anterior teeth, the roots were endodontically treated and prepared for the insertion of a fiber post. Translucent fiber posts (DT) were luted with a dual-curing resin cement (Duo-Link) in 10 specimens (group 1) after the canal walls had been treated with the One-Step bonding system. In the other 10 specimens (group 2), experimental anatomic posts (Anatomic Post'n Core) were tested. To these posts, a layer of light-curing resin is added to allow for a pre-cementation relining of the post, aimed at improving its fit into the endodontic space. For luting, the same adhesive-resin cement combination of group 1 was used. All the roots were sectioned and prepared for SEM observations. At the 1-mm, 4.5-mm, and 8-mm level of each root, cement thickness was measured, and the presence of gaps or voids within the luting material or at its interfaces was evaluated. A statistical analysis was performed to test the significance of differences in the cement layer thickness around the two types of post and at different levels of the same type of post. RESULTS: In the presence of anatomic posts, the cement layer was significantly thinner and more uniform at the coronal and middle level of the root. In both groups, voids and bubbles were detected within the luting material, within the abutment material, and between fiber post and cement. Gaps were also visible between post and relining material. CONCLUSIONS: The resin cement thickness was significantly lower in the anatomic post group than in the control group (standardized posts), except at the apical third of the canal, where there was no statistically significant difference. A good adaptation of anatomic posts was evident in all of the specimens.

Analysis of Variance↗

PubMed2003

A six-week study to evaluate the anti-calculus efficacy of a chewing gum containing pyrophosphate and tripolyphosphate.

OBJECTIVE: A six-week, double-blind, cross-over clinical study was conducted to compare the effect of a new chewing gum containing pyrophosphate (1%) and tripolyphosphate (1%), versus a control chewing gum on supragingival calculus deposits. METHODOLOGY: Twenty-eight adult subjects (mean age 34 +/- 8 years) who entered the study were given a full oral prophylaxis and were assigned to chew two pieces of gum, four times a day for five minutes. The gum, either a test chewing gum or placebo chewing gum, was randomly assigned and the subjects were directed to chew their assigned gum for six weeks. All participants also received a 12-week supply of a sodium fluoride (0.32%) dentifrice (Colgate). They were then scored for calculus deposits using the modified Volpe-Manhold Calculus Index (VMI) by the same two examiners. At the end of the first six weeks, the subjects received a second oral prophylaxis and used the alternate chewing gum for a second six-week period of time. The subjects were again scored for calculus deposits and the study was completed. RESULTS: The results demonstrated a mean VMI of 3.65 +/- 2.82 for the test group, and a mean of 4.24 +/- 3.25 for the placebo group. This difference was significant with paired sample t-test (p < 0.001). CONCLUSION: These results indicated that chewing gum containing pyrophosphate and tripolyphosphate reduced supragingival calculus formation by 13.9%, compared to the placebo chewing gum.

Adult↗

PubMed2003

Anticalculus efficacy of a chewing gum with polyphosphates in a twelve-week single-blind trial.

OBJECTIVE: A twelve-week clinical study was conducted to evaluate the effect of a chewing gum containing pyrophosphate (1%) and tripolyphosphate (1%) on controlling supragingival calculus deposits. METHODOLOGY: One-hundred and seventeen subjects enrolled in the study were randomly assigned to either a test gum or no gum group. Each participant received a full oral prophylaxis. Those chewing the test gum agreed to chew four times a day for five minutes each time over twelve weeks. Those assigned to the no gum group agreed not to chew any gum. After twelve weeks, participants were scored for calculus deposits using the modified Volpe-Manhold Calculus Index (VMI), received a second oral prophylaxis and entered the alternate group in this cross-over format. At the end of the twenty-fourth week, all subjects were again scored for calculus deposits and the study was completed. All participants received a supply of a sodium fluoride (0.32%) dentifrice for the study period. Calculus levels were scored by the same examiner for all measurements and recorded on computer. He was blinded to all treatment assignments. RESULTS: One-hundred and eleven participants completed the study. Six participants left the study but none reported problems linked to the pyrophosphates in the chewing gum. The VMI mean score for the test gum group was 2.55 (+/- 2.50) and the mean score for the no gum group was 4.09 (+/- 3.18). The difference between the mean scores was highly significant with paired sample t-test (p < 0.0001). CONCLUSION: The results indicated that a chewing gum containing tripolyphosphate and pyrophosphate reduced calculus formation by 37.6% compared to a no gum treatment.

Adult↗

PubMed2003

Use of anatomic post and core for reconstructing an endodontically treated tooth: a case report.

A clinical case is presented in which a new type of fiber post was used in combination with the proprietary dual-curing resin cement to bond in a wide, nonrounded root canal. The anatomic post was inserted and the relining resin photopolymerized. The anatomic post was then removed and a luting procedure was performed, as for any other translucent post. The clinical procedure was simple, and a superior fit to the root canal walls was achieved, thus reducing the amount of cement needed. The luting procedure described can be proposed as a clinical technique for routine use when the prepared root canal is too wide or not perfectly round.

Child↗

PubMed2002

An SEM evaluation of several adhesive systems used for bonding fiber posts under clinical conditions.

OBJECTIVES: The objective of this investigation was to evaluate the effectiveness of three 'one-bottle' and two 'three step' adhesive systems (as controls) in the formation of resin tags, adhesive lateral branches and a resin dentin interdiffusion zone (RDIZ) when used to bond fiber posts under clinical conditions. This study was performed using standardized SEM observations and scoring resin tag formation and density. METHODS: Fifty root canal treated teeth, already scheduled for extraction for endodontic or periodontal reasons, were selected for this study. The patients were informed and their written consent was obtained. The samples were randomly allocated to five groups of ten samples each. Group 1: All Bond 2 with C & B (Bisco); Group 2: Scotchbond Multipurpose Plus with Opal Luting Composite (3M); Group 3: Scotchbond 1 in combination with Rely X ARC resin cement (3M); Group 4: One-step with C & B resin cement (Bisco); Group 5: All Bond Experimental with Post Cement HI-X (Bisco). The adhesive systems and resin cements were used strictly according to the manufacturers' instructions. The priming-adhesive solution of each 'one-bottle' system was light-cured before placing the resin cement and the post. Fifty Aestheti-Plus posts (white quartz fiber posts, RTD, France) were used. A week later, the roots were extracted and processed for SEM observations. RESULTS: All the adhesive systems showed a RDIZ and resin tag and adhesive lateral branch formation. Microscopic examination of the restored interfaces of Groups 1 and 2 showed a higher percent of RDIZ than those found in samples of Groups 3, 4 and 5. RDIZ morphology was easily detectable and uniform in the first two thirds of the root canals, whilst in the apical third the RDIZ was not uniformly present. Resin tag morphology and formation were significantly more detectable in the cervical and middle areas than in the apical zone. No statistically significant differences were found among the five groups coronally, while in the apical and middle thirds two 'one-bottle' systems (Groups 3 and 4) showed significantly less resin tags than the control Groups 1, 2 and the experimental Group 5. No statistically significant differences were found among the three 'one-bottle' systems in the three evaluated areas. The standardization of SEM observations and scoring resin tag formation allowed statistical evaluation. CONCLUSIONS: The 'three step' adhesive systems can create a wider micromechanical interlocking between adhesive materials and etched dentin than 'one-step' systems.

Dental Bonding↗

PubMed2002

Influence of a microbrush on bonding fiber post into root canals under clinical conditions.

OBJECTIVE: The objective of this clinical report was to evaluate the effectiveness of a microbrush as a carrier of priming-adhesive solution in formation of resin tags, adhesive lateral branches, and resin-dentin interdiffusion zone (RDIZ) when the brush was used to bond fiber posts under clinical conditions. STUDY DESIGN: Twenty endodontically treated teeth, already scheduled for extraction for endodontic or periodontal reasons, were selected for this study. The patients were informed, and their written consent was obtained. The samples were randomly divided into 2 groups of 10 samples each. In group 1, One-Step (Bisco, Schaumburg, Ill) was applied with a brush with Duo-Link resin cement (Bisco). In group 2, One-Step was applied with a microbrush with Duo-Link resin cement (Bisco). Use of the adhesive systems and resin cements was strictly according to manufacturers' instructions. The priming-adhesive solution was light-cured before the dual resin cement and the post were placed. Twenty Aestheti-Plus posts (white quartz fiber posts; RTD, St. Egreve, France) were used. A week after application, the root samples were extracted and processed for SEM observations. RESULTS: Both adhesive systems showed RDIZ and resin tag and adhesive lateral branch formation. In Group 2 samples, RDIZ morphology was easily detectable and uniform along root canals. Also, resin tag formation was well represented in all thirds. In group 1 samples, resin tag formation at the apical third and RDIZ formation was less evident. Statistically significant differences were found among the two groups at the apical third. CONCLUSION: The microbrush permitted a more uniform RDIZ and resin tag formation along the entire length of the canal than did the standard brush. The microbrush can be routinely used for bonding fiber posts into root canal preparations.

Adhesives↗

PubMed2002

Evaluation of Glyde File Prep in combination with sodium hypochlorite as a root canal irrigant.

The purpose of this study using a scanning electron microscope was to investigate the efficacy of four different irrigation techniques after canal preparation with Profile Ni-Ti rotary instruments. A modified technique for the use of Glyde File Prep is proposed. Forty anterior teeth were divided into four groups, instrumented, and irrigated as follows: physiological solution (group A), 2.5% sodium hypochlorite (group B), 2.5% sodium hypochlorite and Glyde File Prep (group C), and 2.5% sodium hypochlorite and Glyde File Prep applied at the end of the preparation with sterile paper points (group D). After scanning electron microscopic evaluation at three different levels, debris, smear layer, and dentinal tubules were scored. Groups A and B had significantly more smear layer and less open tubules on the canal walls compared with the group C and group D samples. Differences in the mean amount of debris between group A samples and other irrigation regimes were statistically significant.

Chelating Agents↗

PubMed2002

Comparison between two clinical procedures for bonding fiber posts into a root canal: a microscopic investigation.

The purpose of this study was to evaluate the influence of two brushes used as carriers of a primer-adhesive solution as to the formation of resin tags, adhesive lateral branches, and a hybrid layer when used to bond translucent fiber posts. Twenty endodontically treated teeth, extracted for periodontal reasons, were used. The samples were randomly divided into two groups of 10 samples each (Group 1: Microbrush + Scotchbond 1 + Rely X ARC resin cement; Group 2: small plastic brush + Scotchbond 1 + Rely X ARC resin cement). The adhesive system and resin cement were used strictly following manufacturers' instructions. The priming-adhesive solution of the one-bottle system was light-cured before placing the resin cement and the post. Twenty translucent fiber posts were used. After luting procedures, root samples were processed for SEM observations. The adhesive system showed a resin dentin interdiffusion zone (RDIZ), resin tag, and adhesive lateral branch formation. Microscopic examination of restored interfaces of group 1 showed a higher percentage (p < 0.05) of RDIZ than those found in samples of group 2. In group 1 samples, RDIZ morphology was well detectable and uniform in all thirds of the root canals. In group 2, RDIZ was not visible in the apical third. No statistically significant differences were found among the two groups coronally and at the middle third, but the apical third of group 1 showed significantly more resin tag formation than group 2. The characteristic reverse cone shape of resin tags was always noted in the coronal and middle third of the root canals of both groups and in the apical third of group 1. In the apical third of group 2 root canals, the resin tags showed a less uniform morphology and a shorter length than those found in the other observed thirds.

Cementation↗

PubMed2002

Scanning electron microscopic investigation of the surface of fiber posts after cutting.

This study evaluated the surface of different types of fiber posts after cutting and investigated whether different cutting procedures can affect the integrity of the posts. Six types of fiber posts were selected for this study (Carbon Fiber Posts, Quartz Fiber Posts, Aesthetic Posts, Aesthetic Plus Posts, Translucent Posts, Dentatus, FRC Postec Posts). Fifteen posts of each type were studied. All posts had a diameter of 1.2 to 1.4 mm and were between 14 and 16 mm long. Each group was divided into three subgroups (n = 5) according to cutting method: diamond bur, carborundum disk, or scissors. The samples were then processed for scanning electron microscopic investigation. At low magnifications, no microscopic differences were found among the samples of groups 1-4 and 6. Surfaces from group 5 were more irregular, but only when cut using rotating instruments. All groups showed differences between surfaces cut with scissors and those cut with either diamond bur or carborundum disk. Posts displayed regular surfaces after cutting with a diamond bur. Cutting with a carborundum disk produced a mostly regular surface but sometimes produced irregularities close to the surface borders. The surfaces cut with scissors showed two plane and convergent flanges, and because of the formation of fracture lines these posts lost their integrity not only at the cutting surface but also along their length. The results of this study indicated that fiber posts can be cut using a diamond bur mounted in a handpiece under copious water coolant. Although the carborundum disk cutting procedure showed a less regular post surface, it can be speculated that it might be clinically acceptable. The cutting procedure using scissors should be avoided.

Alloys↗

PubMed2002

Influence of microbrush on efficacy of bonding into root canals.

PURPOSE: Recently, several 'one-bottle' systems have been introduced for bonding into root canals. This study evaluated the influence of two brushes used as carriers of a primer-adhesive solution in the formation of resin tags, adhesive lateral branches and hybrid layer when used to bond fiber posts. MATERIALS AND METHODS: Twenty root canal treated teeth, extracted for periodontal reasons, were selected for this study. The samples were randomly divided into two groups of 10 samples each: Group 1: Microbrush + One Step + Dual Link resin cement; Group 2: One Step + Dual Link resin cement. The adhesive system and resin cement were used strictly following manufacturers' instructions. The priming-adhesive solution of the 'one-bottle' system was light-cured before placing the resin cement and the post. Twenty translucent fiber posts were used. Then, root samples were processed for SEM observation. RESULTS: The adhesive system showed resin dentin interdiffusion zone (RDIZ), resin tag and adhesive lateral branch formation. Microscopic examination of restored interfaces of Group 1 showed a higher % (P < 0.05) of RDIZ than those found in samples of Group 2. In Group 2 samples RDIZ morphology was well detectable and uniform in the first two thirds of root canals while in the apical third the RDIZ was not uniformly present while in Group 1 RDIZ was visible at the apical third too. No statistically significant differences were found among the two groups coronally and at the middle third, while the apical third of Group 1 showed significantly more resin tags than in Group 2. The characteristic reverse cone shape of resin tags was always noted in the coronal and middle third of the root canals of both groups and at the apical third of Group 1. In the apical third of Group 2 root canals, the resin tags showed a less uniform morphology and a shorter length than those found in the other observed thirds.

Dental Bonding↗

PubMedDate not supplied

Clinical behavior of translucent-fiber posts: a 2-year prospective study.

PURPOSE: This study prospectively evaluated the clinical performance of three types of translucent posts over a follow-up period of between 2 and 3 years. MATERIALS AND METHODS: Selected were 225 patients with one premolar in need of endodontic treatment, followed by restoration with a fiber post and porcelain crown. The sample was randomly divided into three groups of 75 patients each. The same type of post was used in all patients within a group: group 1 = Aesthetic Plus; group 2 = DT; and group 3 = FRC Postec. For bonding the post, a light-curing adhesive (One-Step) and a dual-curing resin cement (Duo-Link) were applied in group 1 and 2 roots, whereas self-curing materials (Excite DSC as adhesive and MultiLink as resin cement) were used in group 3. After 6, 12, and 24 months, patients were recalled, and a clinical and radiographic examination was performed. For some patients, 30-month follow-up data were also collected. RESULTS: Debonding of the post occurrred in eight cases (3.5%); in another six cases, a recurrence of the periapical lesion was reported. CONCLUSION: The statistical analysis did not reveal any significant difference in the survival rate of the tested posts, suggesting that all are equally and sufficiently reliable for clinical use.

Adolescent↗