A critical analysis of research methods and experimental models to study apical extrusion of debris and irrigants.

During root canal treatment, intra-canal content as well as irrigants and root filling materials may be extruded into the periapical tissues, leading to undesirable consequences such as delay of healing and flare-ups. Although apical extrusion of debris is an inherent occurrence of root canal treatment and no instrument or technique has totally solved this problem, attempts are underway to minimize the harm exerted to periapical tissues with the development of new techniques. This has led researchers to continuously evaluate new instruments and methodologies in terms of apical extrusion. New research on extrusion is frequently published some of which utilize traditional experimental designs and others assessing extrusion using modified or innovative methodologies. This review focuses on the research methods and experimental models to study apical extrusion of debris and irrigants by making a critical analysis of each technique. A PubMed and Scopus search was conducted and 144 articles relevant to apical extrusion were retrieved from 1968 until 2021. The methodologies used in every research article were evaluated and a classification was created. Each methodology is described with the general outlines and advantages and drawbacks of each technique summarized with a critical approach. It appears that the collection of debris in a vial still serves as a method chosen by authors even in most recent studies. On the other hand, development of experimental models that include multiple factors considering the drawbacks of the existing study designs is essential to draw more reliable conclusions on the apical extrusion phenomenon.

Dental Education for Prevention of Oral Cancer in Turkey: Needs for Changing the Curriculum.

The aim of the present study is to evaluate the knowledge, attitudes, and behaviors of dental students on oral cancer in Istanbul, Turkey. A self-administered questionnaire adapted from Tanriover et al. consisting of 48 questions was distributed to 311 students enrolled in the fourth and fifth grades of a dental faculty in Istanbul, Turkey. Questions were grouped under 5 main headings: socio-demographic features, knowledge on risk factors and diagnostic procedures, history taking regarding to alcohol and smoking status, opinions and behaviors of oral cancer, and distribution of dental students according to diagnostic practice of oral cancer. The frequencies and percentages were calculated with descriptive analysis. The differences in distributions were analyzed using the chi-squared test. The p value was set at 0.05 for statistical significance. The overall response rate was 98% (305/311). The majority of the students identified tobacco and alcohol as risk factors (82% and 75.1%, respectively), while older age and inadequate consumption of fruits and vegetables were less likely to be known (60.2% and 52.8%, respectively). Almost one-fifth of the students stated that they have never performed oral cancer examinations during their first or subsequent dental examinations of their patients. Female students thought that dentists were authorized to make oral cancer examinations with a higher frequency compared to males (65.8% and 34.2%, respectively; p = 0.006). On the other hand, female students reported that they did not receive adequate education regarding cessation of smoking with a higher frequency compared with males (69.2% female and 30.8% male respectively; p = 0.0001). As this present study revealed that future dentists had insufficient knowledge in some of the main concepts on oral cancer risk factors, and they lacked the confidence in performing oral examinations in their patients, it is concluded that there is a need for a more structured teaching program with greater emphasis on the early signs and risk factors of OC. Reorganization of the dental curriculum, and courses which further draw attention on the responsibility of the dental practitioner in the detection of oral cancers will be beneficial for the creation of awareness on this significant topic among future dental workforce. Understanding the knowledge and perception of dental students on oral cancers is not only limited to a specific country but it is a worldwide critical issue in which information should be exchanged.

Effect of Premedication on the Success of Inferior Alveolar Nerve Block in Patients with Irreversible Pulpitis: A Systematic Review of the Literature.

BACKGROUND: Failure in the provision of inferior alveolar nerve block anesthesia (IANB) is a significant problem during endodontic treatment of irreversible pulpitis. Various methodologies have been advocated one of which is administration of premedication prior to anesthesia. Despite the considerable number of reports, the topic yet deserves more clarification. This systematic review was conducted to provide an oversight on the effectiveness of premedication prior to IANB in mandibular teeth. METHODS: A PubMed and Cochrane Database search was conducted by using MeSH terms inferior alveolar nerve block + pulpitis and mandibular anesthesia+pulpitis. Two reviewers independently performed the screening, selection of papers, and data extraction. Papers in English language that included randomized clinical studies on the impact of different medications on the success of inferior alveolar block anesthesia in irreversible pulpitis were included. Additionally, relevant supporting literature was also used where necessary. RESULTS: Initially, 118 papers were selected from PubMed and 68 were selected from Cochrane. Five additional articles were retrieved from Google Search. Following the elimination of duplicates and irrelevant articles, 35 studies were selected meeting the criteria. It was observed that there was moderate evidence to suggest that some premedications were partially effective for the enhancement of mandibular anesthetic effect in irreversible pulpitis. CONCLUSION: Though some medications appear to be promising, further supporting research will help highlight this significant topic which requires further clarification.

Evaluation of senior dental students' general attitude towards the use of rubber dam: a survey among two dental schools.

The purpose of this study was to evaluate the general attitude of senior dental students towards rubber dam use, specifically focusing on endodontic practices prior to starting to serve community. Questionnaires were distributed to senior year students of a private school and a state school in Istanbul. Questions were asked about areas where the students used rubber dam, its advantages and difficulties, and whether they agreed or disagreed with some aspects of the rubber dam. The private school students rated isolation whereas those of the state school selected prevention of aspiration which the top advantage rubber dam provides. Students of the state school agreed with the opinion that isolation cannot be achieved without rubber dam and it extended the procedure with a significantly higher ratio compared to the private school. Within the limitations of the present study, it can be concluded that the perceptions of dental students on rubber dam needs to be improved and strategies should be developed so that this valuable adjunct will comprise one of the indispensable elements of dental care.

Investigation of the effect of different prefabricated intracanal posts on fracture resistance of simulated immature teeth.

AIM: The aim of this study was to assess fracture resistances of simulated immature single-rooted teeth whose roots have been backfilled using 3 different post systems after a 4 mm apical mineral trioxide aggregate (MTA) placement. MATERIALS AND METHODS: Forty-eight maxillary anterior teeth were assigned into four groups. The lengths of each root were standardized by cutting off the coronal and apical portions to obtain 13 ± 1 mm samples and root canals were enlarged. The #6 Peeso reamers were allowed to protrude 1 mm beyond apex to simulate immature teeth. Apical 4 mm of each tooth was filled using MTA. The remaining portions were treated as follows: Group 1 (Control): AH Plus + Gutta-percha cold lateral compaction. Group 2: Glass fiber posts (FRC Postec Plus post) cemented using self-adhesive resin cement. Group 3: Quartz fiber posts (D.T. Light post) cemented using self-adhesive resin cement. Group 4: Zirconia posts (Cosmopost) were placed using self-adhesive resin cement. Specimens were embedded in self-curing acrylic. A compressive load was applied lingually at a crosshead speed of 1 mm/min at an angle of 45º until fracture in a universal testing machine. RESULTS: The mean fracture resistances were 823.17 ± 188.80, 1155.50 ± 190.37, 1208.00 ± 254.32, and 1153.25 ± 195.71 Newtons for Groups 1, 2, 3, and 4, respectively. All experimental groups had significantly higher fracture resistance compared with the control group (P < 0.01). No statistically significant difference was noted between the experimental groups (P > 0.05). CONCLUSIONS: All post systems exerted a similar reinforcing effect to a simulated immature tooth and may be preferred specifically in situations which require additional reinforcement.

Comparison of the radiopacities of different root-end filling and repair materials.

This study evaluated the radiopacity of 3 repair materials, Biodentine, MM-MTA, and MTA Angelus. Standardized cylindrical rings were prepared. Samples of Biodentine MM-MTA and MTA Angelus were prepared (n = 10 in each group), filled into the rings, and preserved at 37°C until setting. A 1 mm thick dentin slice was used as control. All set specimens were removed and radiographed along with the dentine slice and a graduated aluminium step wedge. Digital images were transferred to the computer using a software. The radiographic densities of the specimens were determined, and the values were converted into millimetres of aluminium (mm Al). One-way ANOVA was used for intergroup comparison, whereas Tukey HSD test was used for detecting the group with the difference. The mean radiopacities of Biodentine, MTA Angelus, and MM-MTA were 2.8 ± 0.48, 4.72 ± 0.45, and 5.18 ± 0.51 mm Al, respectively. The radiopacity of Biodentine was significantly lower compared to other materials (P = 0.001), whereas no significant difference was noted between MTA Angelus and MM-MTA (P = 0.109). All materials had significantly higher radiopacities compared to dentine. The relatively lower radiopacity of Biodentine can be improved to achieve more reliable results in procedures such as retrograde fillings.

An overview of clinical studies on fiber post systems.

Intraradicular posts are useful adjuncts in the restoration of endodontically treated teeth. These systems have undergone a significant evolution in recent years, and fiber-reinforced systems have started to be incorporated into routine clinical care more frequently. Despite the high number of laboratory studies pertaining to the characteristics of fiber posts, clinical studies evaluating their general success rates are rather limited. Since clinical investigations are reliable means to achieve information about the general behavior pattern of materials or techniques, assessment of this data will be beneficial to have a better understanding of fiber-reinforced intraradicular post systems. The purpose of this paper was to make a summary of clinical studies regarding various fiber posts. A PubMed search was conducted and articles dating back to 1990 were retrieved. The paper provides an overview of clinical studies on fiber posts specifically in the last decade as well as commentary analysis.

Assessment of root canal treatment outcomes performed by Turkish dental students: results after two years.

The aim of this study was to evaluate radiographically the periapical status and technical standard of root canal therapies performed by a group of undergraduate dental students in Turkey two years following completion of the treatments. A random sample of 264 patients who received root canal treatment from undergraduate students at the Yeditepe University Faculty of Dentistry in 2009 were recalled after two years. The study sample consisted of 319 root-filled teeth in 158 dental patients (females=97, males=61) who presented to the student clinics during that time frame. For each root-filled tooth, two periapical radiographs were examined to identify the periapical status, one showing pre-treatment and the other showing post-treatment status. The quality of endodontic treatment was examined according to the distance between the end of root filling and radiographic apex and the density of the obturation according to presence of voids within the root filling material. This examination found that 54.2 percent of roots had fillings of acceptable length, while 37.3 percent were short, 7.8 percent were overfilled, and 0.6 percent was unfilled; 2.5 percent of the teeth were observed with broken root canal instruments. After two years, PAI scores of teeth with acceptable length of root canal filling (0-2 mm from the radiographic apex) were found to be lower than those of the overfilling and short filling cases (>2mm) (p<0.01). Moreover, voids were detected in the root canal fillings of 52.7 percent of endodontically treated teeth. The PAI scores of root fillings with inadequate density were significantly higher than adequate ones (p<0.01). Although endodontic treatments performed by undergraduate students do not appear to be unqualified compared to those performed by general practitioners, more emphasis must be placed on the technical quality of endodontic treatment to obtain better results.

Antibacterial effects of two different types of laser and aqueous ozone against Enterococcus faecalis in root canals.

OBJECTIVE: The purpose of this study was to investigate the antibacterial effects of two different types of laser and aqueous ozone in human root canals infected by Enterococcus faecalis. BACKGROUND DATA: Many techniques have been developed to find an alternative to sodium hypochlorite as a disinfection agent for infected root canals. However, no study has evaluated the exactly the same antimicrobial agent with sodium hypochlorite (NaOCl). METHODS: Eighty mandibular premolar teeth with single roots and canals were selected. Following root canal preparation and irrigation, sterilization was performed in an autoclave. E. faecalis was incubated in the root canals and kept at 37°C for 24 h. The teeth contaminated with E. faecalis were divided into one negative control group (NaOCl) and three experimental groups; (Er:YAG laser, KTP laser, and aqueous ozone groups)(n=20). A disinfection procedure was performed for 3 min in order to standardize all groups. After this procedure, the microbial colonies were counted. RESULTS: The results indicated that whereas the NaOCl group exhibited the highest antibacterial effect among all groups, the aqueous ozone showed the highest antibacterial effect among the experimental groups. Whereas a statistically significant difference was noted between the aqueous ozone and laser groups (p<0.05), the difference between the Er:YAG and KTP lasers was not statistically significant (p>0.05). CONCLUSIONS: The results showed that when aqueous ozone was applied with the aim of disinfecting the root canals, it exhibited a higher antibacterial effect than the KTP and Er:YAG lasers. However, the antibacterial effect of the aqueous ozone was insufficient when compared with NaOCl.

Evaluation of dental students' perception and self-confidence levels regarding endodontic treatment.

OBJECTIVES: The aim of this study was to obtain information about senior dental students' perceptions and self-confidence levels regarding endodontic practice. MATERIALS AND METHODS: Anonymous survey forms were handed out to senior students at Yeditepe University, Faculty of Dentistry. The students were asked to score their level of confidence using a 5-point scale and comment about future practices. RESULTS: The response rate of the survey was 88%. 11.9% expressed endodontics as the first branch in terms of difficulty. The majority (90.5%) indicated they would perform root canal treatments within their expertise limit in the future but refer difficult cases to an endodontist. Bleaching of endodontically treated teeth, managing flare-ups, placement of a rubber dam were procedures in which students reported the lowest confidence (2.55 ± 1.17, 3.24 ± 0.96, 3.24 ± 1.19, respectively). On the other hand, students felt the lowest confidence in the treatment of maxillary molars followed by mandibular molars (3.43 ± 1.02 and 3.93 ± 0.97, respectively). Students also reported the lowest confidence in root resorptions, endo-perio lesions, traumas, retreatments and apexifications (2.93 ± 1.16, 3.07 ± 0.89, 3.24 ± 0.85, 3.33 ± 1.7 and 3.36 ± 1.1, respectively). CONCLUSIONS: The results showing students' lower confidence in more challenging aspects of dentistry may be related with the attitude of dental schools to refer these cases to post graduate students and instilling information about these cases on a theoretical basis only. Though there seems to be a tendency for students to refer challenging cases to a specialist in future, authorities should give priority to enhance the way information and experience is conveyed regarding various aspects of endodontic treatment.

Cross-sectional evaluation of post-operative pain and flare-ups in endodontic treatments using a type of rotary instruments.

AIM: The purpose of this clinical study was to evaluate the general incidence of post-operative pain and flare-ups in patients who were endodontically treated by two endodontics specialists using rotary instruments (Hero 642, Micro Mega, France) with the same treatment protocol. METHODS: Records of 382 teeth belonging to 268 patients treated by two endodontics specialists during a 6-month period were kept and evaluated. Post-operative pain between treatment visits was categorized using a pre-established scoring system. Ninety-five patients were males, whereas 173 were females. RESULTS: Pulpal necrosis without periapical pathosis was determined as the most common indication for endodontic treatment (21.7%) followed by irreversible pulpitis and re-treatment without periapical lesions (18.3%, 18.3%, respectively). The general prevalence of post-operative pain and flare-ups was determined as 8.1%, whereas cases that could be classified as real flare-ups which were severe and required an unscheduled visit (scores 2 and 3) comprised 3.4% of the cases. No statistically significant correlation was determined between gender and post-operative pain and flare-up (p = 0.05). There was a significant correlation between number of appointments and the presence of pain and flare-ups. Teeth undergoing multiple visits had a higher risk of developing post-operative pain and flare-ups compared to those with single appointments with a statistical significance (p = 0.03). CONCLUSIONS: Teeth with pre-operative pain were more prone to developing post-operative pain and discomfort with a statistically significant difference (p = 0.02). While no significant correlation was determined between tooth vitality and pain and flare-ups (p = 0.5), a statistically significant relationship existed between the presence of a periapical pathosis and post-operative pain and flare-ups. Cases with a periapical lesion had a higher risk of developing pain and flare-ups compared to those with no periapical involvement (p = 0.0001). Future studies may focus on the influence of rotary instrumentation systems in more specific groups of cases. Meanwhile; microbiological as well as psychological aspects of flare-ups are topics that warrant further investigation.

Photodynamic therapy in dentistry: a literature review.

OBJECTIVES: The purpose of this review was to summarize recent developments regarding photodynamic therapy (PDT) in the field of dentistry. MATERIALS AND METHODS: A review of pertinent literature was carried out in PubMED to determine the current position of PDT applications in dentistry. One hundred thirteen relevant articles were retrieved from PubMED by inserting the keywords "photodynamic therapy", "dentistry", "periodontology", "oral surgery", and "endodontics". It is anticipated that this overview will create a specific picture in the practitioner's mind regarding the current status and use of PDT. RESULTS: In spite of different results and suggestions brought about by different researchers, PDT can be considered as a promising and less invasive technique in dentistry. CONCLUSION: PDT seems to be an effective tool in the treatment of localized and superficial infections. Within the limitations of the present review, it can be concluded that although PDT cannot replace antimicrobial therapy at its current stage, it may be used as an adjunctive tool for facilitating the treatment of oral infections. CLINICAL RELEVANCE: Oral infections (such as mucosal and endodontic infections, periodontal diseases, caries, and peri-implantitis) are among the specific targets where PDT can be applied. Further long-term clinical studies are necessary in establishing a more specific place of the technique in the field of dentistry.

Evaluation of reasons for extraction of crowned teeth: a prospective study at a university clinic.

OBJECTIVE: The aim of this study was to determine and classify the major reasons for extraction of teeth with full crowns belonging to patients admitted to a university clinic within a specific time frame. METHODS: Two hundred and eight extracted teeth with full crown belonging to 75 patients were included. Apart from demographic information, reasons for presenting to the hospital, the major reason for extraction, the type of the crown (single crown, bridge abutment, abutment for removable prosthesis), presence of posts, age of restorations, presence of an endodontic treatment and quality were recorded. Comparable data were statistically analyzed using the chi-square test. RESULTS: Forty-three (57.3%) of the patients were females, whereas 32 (42.7%) were males with an average age of 63.21 ± 13.56. A statistically significant relationship was determined between age groups and rate of extractions, with the lowest extractions detected in the 35-44 years age group and the highest in the 55-64 years age group (p = 0.001). Tooth mobility was the predominant reason for patients' initial presentation (52.9%). The most encountered reason for extraction was periodontal reasons with a prevalence of 59.1%, followed by caries (26.9%) and periapical lesions (12%); 35.6% of extracted teeth had endodontic treatment. Sixty teeth (81.1%) had incomplete root fillings. There was a significant relationship between extractions and incomplete root fillings (p = 0.001). CONCLUSION: Studies comprising other faculty clinics as well as general practices will be complementary in making more generalized statements regarding the etiology of extractions of crowned teeth.

The status of mineral trioxide aggregate in endodontics education in dental schools in Turkey.

The aim of this study was to assess the current status of mineral trioxide aggregate (MTA) as an educational material in dental schools in Turkey. A survey was sent to senior members of the endodontic departments of seventeen dental schools; fourteen responded. All respondents reported that they used MTA in their clinical practice, with apexification, perforations, retrograde fillings, and root resorptions being the most frequently occurring treatment procedures. All reported that information was given to students regarding MTA mainly as part of the curriculum. The third and fourth years were the periods when MTA was introduced to students in most of the schools. Twelve schools reported that students had the opportunity to observe procedures in which MTA was used, but students had the chance to use the material in a very minor proportion of the schools, mainly under the supervision of clinical instructors. Ten schools agreed that MTA should be included in the regular endodontic curriculum. Financial constraints seemed to be the predominant reason for those who answered this question negatively, followed by difficult handling properties and low radiopacity of the material. Within the limitations of this study, it can be concluded that ways should be sought to prevent financial difficulties from depriving dental students of the opportunity to receive information about contemporary methodologies such as MTA utilization.

Demographic profile and future expectations of students enrolled in a Turkish private dental school.

The purposes of this study were to obtain information about the social and demographic profile of students enrolled in the first private Turkish dental school, to gather information regarding the reasons for their preferences, and to obtain data about their career expectations. Questionnaires were distributed to 278 students; 229 returned the survey for an overall response rate of 82 percent. Of the respondents, 145 (65.5 percent) were females and seventy-five (34.5 percent) were males; they had an average age of 21.62±1.58. First degree relative (mother, father, sibling) had the greatest influence on the students in choosing dentistry as a career. Fathers and mothers had similar impact on the students' choice of dental profession (45.9 percent and 46.6 percent, respectively). Humanistic feelings, desire to serve others, and reasonable working hours were the predominant reasons that motivated females to become a dentist (p<0.05). Also, academic interest and interest in a medical field were significantly influencing factors for female students (p<0.05 and p=0.001, respectively). One-hundred and ninety-seven students (86 percent) expressed a goal of specializing in a specific branch of dentistry; orthodontics and oral and maxillofacial surgery were the top-ranked specialties. Although only 41 percent of the students were of Istanbul origin, 82.5 percent reported that they wish to practice in Istanbul.

Comparison of the fracture resistance of simulated immature permanent teeth using various canal filling materials and fiber posts.

BACKGROUND: The purpose of this study was to compare the fracture resistances of immature teeth treated with MTA along with root canal obturation methods using AH Plus, MetaSEAL, MTA Fillapex sealers + lateral compaction technique, and Unicore quartz fiber posts. MATERIALS AND METHODS: Fifty single-rooted maxillary anterior teeth were divided into five groups. The crowns were dissected and root canals were enlarged. #6 Peeso reamers were allowed to protrude 1 mm. beyond the apex to simulate immature teeth. The apical 4-5 mm of each tooth was filled using Angelus white MTA. The remaining portions of canals were obturated as follows: Group 1: No backfilling (control), Group 2: AH Plus + gutta-percha, lateral compaction, Group 3: MetaSEAL + gutta-percha, lateral compaction, Group 4: MTA Fillapex + gutta-percha, lateral compaction, Group 5: UniCore Fiber posts luted using PermaFlo DC. The specimens were embedded into self-curing acrylic poured into identical cylinders which were mounted on a jig providing a 45° angle. A compressive load increasing at 1 mm min(-1) was applied and the maximum load at which fracture occurred was recorded. Statistical analysis was performed using Kruskal-Wallis and Dunn's multiple tests. RESULTS: The highest fracture resistance was obtained with Group 5 (Fiber posts) whereas Group 4 (MTA Fillapex) yielded the lowest values. The mean fracture resistance value of Group 2 (AH Plus) was significantly higher than Group 4 (MTA Fillapex) (P = 0.001). The mean fracture value of Group 5 (Fiber posts) was significantly higher than Group 2 (AH Plus), Group 3 (MetaSEAL), and Group 4 (MTA Fillapex) (P = 0.02, 0.004, and 0.0001, respectively). CONCLUSION: Within the limitations of this study, UniCore quartz fiber posts provided the highest resistance. This methodology may specifically be advantageous for teeth with arrest of development at early stages, as these teeth are more susceptible to fracture owing to their excessively weak dentinal walls.

Microleakage of various root filling systems by glucose filtration analysis.

OBJECTIVE: The aim of this study was to evaluate the microleakage of Resilon + Epiphany, EndoRez, Activ GP, and conventional AH Plus + gutta-percha technique using the glucose filtration model. STUDY DESIGN: One hundred twenty maxillary incisors were divided into 5 experimental and 2 control groups. After root canal shaping, the experimental groups were filled with AH Plus + gutta-percha (lateral compaction), Resilon + Epiphany (lateral compaction), AH Plus + Protaper's proprietory cone, EndoRez + sealer, or Activ GP + sealer). The specimens were mounted on a glucose model and samples were taken for 3 weeks for leakage measurement. RESULTS: No statistically significant difference was observed between the leakage of all groups at the 3 testing periods (P > .05). CONCLUSION: The filling materials with the monoblock concept do not seem to be superior to the conventional AH Plus + gutta-percha system regarding microleakage.

The effect of endodontic irrigants on the microtensile bond strength of dentin adhesives.

INTRODUCTION: The purpose of this study was to evaluate the microtensile bond strength of a total etch (XP-Bond) and a self-etch (Clearfil SE Bond) adhesive system to dentine surfaces treated using endodontic irrigants. METHODS: Twenty-four freshly extracted third molars were used. After creating a smear layer on the coronal midthird portion of the crowns, the teeth were divided into three groups and surfaces were irrigated with distilled water, 5.25% NaOCl + 17% EDTA, and 1.3% NaOCl + BioPure MTAD, respectively. Each group was divided into two subgroups, and a self-etching adhesive and an etch-and-rinse adhesive were applied respectively. The teeth were restored with a composite material and sectioned to produce sticks for microtensile bond testing. RESULTS: The microtensile bond strength of the MTAD + Clearfil SE group was found to be significantly lower than the microtensile bond strength of the distilled water + Clearfil SE Bond group and the NaOCl, EDTA, + Clearfil SE Bond group (p = 0.0001, p = 0.009). CONCLUSIONS: Because of the significant reduction of Clearfil SE Bond to coronal dentine after MTAD application, an etch-and rinse adhesive such as XP-Bond may be preferred if this irrigant has been chosen during endodontic treatment.

Endodontic and surgical management of a maxillary lateral incisor with type III dens invaginatus: a 12-month follow-up.

This article reports the endodontic and surgical management and 12-month follow-up of a maxillary lateral incisor diagnosed as type III dens invaginatus. A 21-year-old male patient presented to our clinics with complaints of pain and swelling in the right maxillary region. Intraoral and radiographical examination disclosed the presence of a peg-shaped maxillary right lateral incisor diagnosed as type III dens invaginatus. Root canal treatment combined with periapical surgery was initiated. After the completion of root canal treatment for both maxillary right central and lateral incisors, periapical surgery was scheduled. During the surgery, periapical granulation tissue was curreted and bovine-derived hydroxil apatite (Unilab-Surgibone, Mississauga, Ontario, Canada) covered with collagen membrane (Unilab-Surgibone) was placed in the resorptive areas. ProRoot MTA (Dentsply, Tulsa, OK) was placed as a root end filling material. Postoperative 12-month follow-up revaled a satisfactory healing process.

Evaluation of the effect of different ferrule designs on the fracture resistance of endodontically treated maxillary central incisors incorporating fiber posts, composite cores and crown restorations.

AIM: The purpose of this study was to evaluate the fracture resistance of endodontically treated maxillary central incisors restored with quartz fiber posts, composite cores, and crowns when different types of ferrule designs were incorporated. METHODS AND MATERIALS: Sixty maxillary incisors were divided into six groups: Group 1 (control): teeth with root canal treatments having a full crown prosthesis; Group 2: teeth with a 2 mm circumferential ferrule; Group 3: teeth with a 2 mm ferrule only in the vestibular region; Group 4: teeth with a 2 mm ferrule only in the palatal region; Group 5: teeth with a 2 mm ferrule in the vestibular and palatal region, having cavities in both proximal areas; and Group 6: teeth with no ferrule. The teeth in the experimental groups were restored with quartz fiber posts-composite cores and full metallic crowns. All experimental teeth were subjected to an increasing compressive force with a crosshead speed of 1 mm/min, until fracture occurred. RESULTS: The median fracture values of groups were as follows: Group 1: 574.4 N, Group 2: 472.4 N, Group 3: 474.3 N, Group 4: 480.7 N, Group 5: 463.1 N, and Group 6: 297.9 N. A statistically significant difference was found between Group 1 and Group 6 (p< 0.01). CONCLUSION: It was concluded different ferrule designs did not have any influence on the fracture resistance of teeth with fiber posts. The results of this study indicate fiber posts can safely be used for their reinforcing properties. Furthermore, there is no significant change in the resistance of teeth with fiber posts regardless of which ferrule design is incorporated. The property of these types of posts is an additional advantage in clinical practice.