Round Carbide Bur Research Articles

A novel 'stop-hole' strategy to extend the fatigue life of orthodontic thermoformed retainers: an in vitro study.

This study aimed to investigate the potential to limit crack propagation in thermoformed retainers (TRs) and extend their fatigue life by placing a 'stop-hole'. Thirty-two TRs, fabricated from 1mm thick, round polyethylene terephthalate glycol (PETG) blanks of ICONIC®, underwent testing within a custom-built fatigue tester. After initial crack growth of 3mm, the TRs were divided into three groups: a control group (C) and two experimental groups based on the stop-hole placement method. In the first experimental group, stop-holes were placed using a 1mm round carbide bur on a slow-speed handpiece (ES), while the second group utilized a heated 1-mm-width ball-ended CPITN probe (EH). Following the placement of a stop-hole at the crack-tip, all 32 TRs resumed testing until the final crack length of 10mm was reached. Stop-hole placement significantly prolonged the delay in crack re-initiation in both experimental groups compared to the control group (P < .001 for both). The mean re-initiation times for the ES and EH groups were 104.50 and 129.50min, respectively, whereas the control group was 28.94min. Consequently, this discrepancy was reflected in the total testing times, with both experimental groups requiring significantly longer time to reach the final crack length (P < .001). There was no significant difference in the testing times between the two experimental groups. This is an in vitro study. The stop-hole methodology significantly extended the fatigue life of a TR in a controlled laboratory environment.

Comparative evaluation of blood contamination on the push-out bond strength of mineral trioxide aggregate, Biodentine, and bone cement in furcation perforation repair: An in vitro study

ABSTRACT Aim: This in vitro study was designed to compare the effect of blood contamination on the push-out bond strength of mineral trioxide aggregate (MTA), Biodentine, and bone cement. Materials and Methods: Seventy-eight human mandibular molars with furcation were selected and decoronated at the cementoenamel junction. The samples were mounted 3 mm below the furcation area into the acrylic resin. A perforation in the center of the furcation was made using a round carbide bur size 3 with a diameter of 1.2 mm. Then, the perforation was enlarged up to a standardized diameter of 1.3 mm using a size 5 Gates-Glidden drill. The samples were randomly divided into three groups. Based on blood contamination status, each group (n = 26) was further subdivided into two subgroups (n = 13). Whole fresh human blood was obtained from the principal investigator of the research group. A 27-gauge syringe was used to inject blood into the perforated furcal area. A piece of gelatin was packed under the furcal area using a condenser. MTA, Biodentine, and bone cement were mixed according to the manufacturer’s recommendations and compacted into the perforation. A universal testing machine was used to evaluate the push-out bond strength. Statistical Analysis: The results were analyzed using one-way analysis of variance followed by Tukey’s post hoc test (P &lt; 0.05). Results: In the experimental groups with blood contamination, Group 2A exhibited statistically significant push-out bond strength values compared with Group 1A and Group 3A. In the groups without blood contamination, Group 2B showed statistically significant push-out bond strength values compared with Group 1B and Group 3B. Irrespective of the blood contamination status, Group 3 exhibited higher push-out bond strength values than Group 1, with no statistically significant difference between the groups. No significant difference was observed within the groups. Conclusion: Biodentine showed promising results as a better perforation repair material irrespective of the status of blood contamination. Bone cement can be a viable alternative material for furcation perforation repair compared with MTA.

Effect of Erbium, Chromium-doped: Yttrium, Scandium, Gallium and Garnet Laser Tooth Preparation on Gap Formation of Universal Adhesive Bonded to Enamel and Dentin: A Micro-CT and SEM Study.

Introduction: The presence of gaps at the bonding interface of resin composite restorations is known to have an impact on restoration longevity. This study aimed to evaluate the effect of erbium, chromium-doped yttrium, scandium, gallium, and garnet (Er, Cr:YSGG) laser irradiation on gap formation at the tooth-resin interface and to compare the reliability of micro-computed tomography (µCT) and scanning electron microscopy (SEM) scans for gap formation assessment. Methods: Thirty standardized non-retentive class V cavities were prepared on sound human premolars using either an Er,Cr:YSGG laser or a round carbide bur (n=15 for each). A universal adhesive and A nano-filled resin composite were applied in accordance with the manufacturer's recommendations. After water storage for 24 hours at 37°C, the teeth were subjected to thermocycling. Gap formation assessments were performed by µCT (Skyscan 1173 µCT, Brucker, Belgium) and SEM (JEOL JSM-6610LV, Japan), and SPSS version 24.0 (IBM Inc., Chicago, USA) was used to analyze the data at P value<0.05. Descriptive statistics were used to describe the gap formation percentages. To compare the impact of both preparation and assessment methods, a non-parametric Mann-Whitney U test was used. Results: In enamel, similar gap formation values were detected for the two preparation methods (bur and laser). However, the laser-prepared group showed higher gap formation values in dentin. Additionally, higher gap formation values were reported for both preparation methods when µCT was used for assessment. Conclusion: Cavity preparation using a Waterlase laser led to higher gap formation percentages at the dentin-resin interface. In addition, SEM assessment is more reliable for assessing the tooth-resin interface.

Push-Out Bond Strength of EndoSeal Mineral Trioxide Aggregate and AH Plus Sealers after Using Three Different Irrigation Protocols.

The current study was designed to assess the bonding strength of EndoSeal MTA and AH Plus sealers after using three irrigation protocols as follows: (1) 17% Ethylenediamine tetraacetic acid, (2) 7% maleic acid, and (3) 37% phosphoric acid. Push-out bond strength was evaluated for 60 middle root slices of 1-mm thickness each. They were horizontally cut from freshly extracted single-rooted human teeth. A hole in the root canal was made using a carbide round bur of 1.1 mm in diameter in a middle third root slice. Specimens were dipped in 2.5% NaOCl, and then they were grouped into three groups; G1: 17% EDTA, G2: 7% maleic acid, and G3: 37% phosphoric acid as a final irrigant for 3 minutes. Each group was subdivided into two subgroups, according to the type of sealer, either EndoSeal MTA or AH Plus. After the full set of the sealer, the bond strength was evaluated with the push-out test by applying a force to each slice using a plunger with a 1-mm diameter. The one-way Tukey's post hoc test, analysis of variance (ANOVA) test, and Student's t-test were utilized to gather data and statistically evaluate it. The irrigation protocol used exhibited significant influence on the bond strength of EndoSeal MTA and AH Plus sealers. AH Plus sealer subgroups showed the highest bond strength with 7% maleic acid, followed by 37% phosphoric acid, and 17% EDTA. While in the EndoSeal MTA sealer subgroups, the highest bond strength was shown with the 17% EDTA followed by 7% maleic acid and 37% phosphoric acid, respectively. The present study revealed that the type of the final irrigant significantly impacts the bond strength of the sealer used. The AH Plus sealer bond strength was improved by using the 7% maleic acid as a final irrigant. In contrast, the EndoSeal MTA sealer showed the best results with the 17% EDTA as a final irrigant.

Histological evaluation of the synergistic effect of chitosan and mineral trioxide aggregate on mechanically exposed dental pulp following pulp capping in dogs' teeth

Introduction: This work studied the synergistic effect of chitosan and mineral trioxide aggregate (MTA) on mechanically exposed dental pulp following pulp capping in dogs' teeth.Materials and Methods: Class V cavities were prepared in 60 teeth of 3 mongrel dogs. These cavities were prepared approximately 1 mm coronal to the gingival margin by using a round carbide bur #2 with water cooling. These teeth were divided according to the pulp capping material into 2 groups (30 teeth each); Group I: MTA and Group II: a combination of MTA and chitosan compound. The cavities were restored by self-curing glass ionomer cement, followed by varnish application to provide the suitable conditions for pulpal repair. Both groups were further subdivided according to the evaluation period into 3 subgroups (10 teeth each); subgroup A: 7 days, subgroup B: 21 days, and subgroup C: 60 days. Histological evaluation of dentin bridge formation was performed after pulp capping in all subgroups. Data were statistically analyzed by ANOVA, Tukey's post hoc, Kruskal–Wallis, and Mann–Whitney U-tests. The significance level was set at P ≤ 0.05.Results: No statistically significant difference was found between both groups at all evaluation times (P > 0.05). The combination of MTA and chitosan did not improve the quality of dentin bridge produced by the MTA alone.Conclusion: Mixing of chitosan and MTA as a direct pulp capping material has no synergistic odontogenic effect in dog's teeth.

HISTOLOGICAL ANALYSIS OF REPARATIVE DENTIN FORMATION USING BIO DENTINE AND MTA AS PULP CAPPING AGENT: AN IN VIVO STUDY

Aim: The study carried aim of comparing and evaluating the efficiency of Biodentine, MTA on pulp repair. Materials and method: 40 Dental patients between age group of 18yrs-26yrs which were scheduled for premolars extraction for orthodontic reason were selected. Specimens were allocated two groups. After Local anesthesia and complete isolation with rubber dam. Preparation of the ideal class I cavity by using sterile straight carbide bur (0.8mm) was done. an exposure of approximately 1.2 mm in diameter was done at center of the pulpal floor with round carbide bur of diameter of 1.2 mm was done Group I Exposed pulp of the teeth was capped with 2 mm of thick layer MTA ,Group II Exposed pulp of the teeth was capped with 2 mm thick layer of Biodentine. After 30 seconds Glass ionomer (GC Fuji II, Japan) restoration was done. Atraumatic extraction was conducted after 8 weeks. Specimens were prepared for histological analysis and Evaluated beneath light microscope at 4x and 400x magnification for inflammatory cell response, Tissue disorganization, and hard tissue formation. Results: Significance difference was seen in intensity and extensity of inflammatory cells, tissue disorganization and hard tissue formation among two groups (0.00

Spectrophotometric analysis evaluating apical microleakage in retrograde filling using GIC, MTA and biodentine: an in-vitro study

BackgroundThe present study compares the apical microleakage of three different root-end filling materials in which the retrograde cavity is prepared by two different burs.MethodsEighty extracted single rooted maxillary and mandibular premolars were taken. Root canal treatment was completed. Apical 3 mm of all the teeth were resected with diamond disk. The tooth were divided into four groups with two subgroups for each group containing 10 tooth (N = 10) as: Group IA (Negative Control and IB (Positive Control); Group IIA and IIB: Prepared with round carbide bur and round diamond bur respectively, filled with GIC; Group IIIA and IIIB: Prepared with round carbide bur and round diamond bur respectively, filled with MTA; Group IVA and IVB: Prepared with round carbide bur and round diamond bur, filled with Biodentine. After applying two coats of nail varnish leaving apical 3 mm (except for negative control group) all teeth were immersed in 2% methylene blue for 3 days and again in 65% nitric acid for next 3 days for extraction of dye. The obtained solution was then transferred to eppendorf tube and centrifuged in microcentrifuges at 14,000 revolution per minutes (RPM) for 5 min. Optical density or absorbance of the supernatant solution was measured with UV spectrophotometer at 550 nm.ResultsThe absorbance of the supernatant solution after dye extraction is decreasing in the order of positive control> GIC > MTA > Biodentine> negative control group. The significant difference was observed between GIC and MTA (p = 0.0001) and GIC and Biodentine (p = 0.0001) with two different burs but statistically non-significant difference was observed between MTA and Biodentine with Carbide bur (p = 0.127) and Diamond bur (p = 0.496) respectively.ConclusionsWithin the limitations of the present study, it can be concluded that Biodentine and MTA showed less microleakage as compared to GIC. There is no significant difference between mean microleakage of MTA and Biodentine. However, the mean OD of the Biodentine was least of all evaluated materials. Preparation of the root-end using round carbide bur as well as round diamond burs showed comparable microleakage for all three filling materials.

Comparative evaluation of occlusal pits and fissures morphology modification techniques before application of sealants: An In vitro study.

Pits and Fissures are recognized as being highly susceptible to caries. Pit and fissure sealants are one of the best methods of preventing caries as it occludes the fissures and pits from the accumulation of plaque and cariogenic microflora. There are different methods of cleaning and preparing occlusal pits and fissures for preventing caries which helps in alleviating oral health status of paediatric population. The aim of the present study was to evaluate and compare the microleakage of pit and fissure sealants after using five different preparation techniques, namely: A) Conventional technique using pumice prophylaxis, B) enameloplasty with round carbide bur, C) enameloplasty with fissurotomy bur, D) air polisher, and E) air abrasion. The study was conducted on 50 caries-free premolars extracted for orthodontic purpose. These teeth were randomly assigned to five groups, 10 teeth in each for receiving fissure sealant after different surface preparation; thermocycling and sectioning of samples were performed and microleakage was assessed under a stereomicroscope after methylene blue dye immersion. The results of air abrasion groups were significantly superior with "0" microleakage when compared to all other groups followed by round bur, fissurotomy bur, air polisher and pumice prophylaxis. To improve the marginal adaptation of the sealants, minimally invasive methods are the most favoured methods of occlusal preparation. This study promises to show positive results for fissure sealants which are likely to play an important role in caries prevention and techniques that are intended to protect caries susceptible surfaces.

Wear of nanohybrid and microfilled composite resin in occlusal restoration of first permanent molar tooth

This study compared the wear of nanohybrid and microfilled composite restorative material in occlusal restoration of first permanent molar tooth. In total, 60 first permanent molar teeth having carious lesion without any clinical and radiological indication of pulpal involvement, removal of carious dental hard tissues was performed using round carbide bur and a class I cavity was prepared, rinsed with water and then dried with gentle air. These cavities were filled with either nanohybrid or microfilled composite resin by simple random sampling by lottery method. All teeth were subjected to clinical qualitative and quantitative wear test at baseline, 3, 6 and 9 months observation period. The quantitative wear was analyzed by profile meter. The results showed that the wear depth of microfilled was significant than the nanofilled composite resin. It can be concluded that quantitative wear of microfilled had greater wear than that of nanohybrid composite restorations.

PAIN ASSESSMENT DURING THE REMOVAL OF INFECTED CARIOUS DENTIN USING CERAMIC BURS WITHOUT LOCAL ANESTHESIA IN CHILDREN

Negative dental experiences in childhood can lead to dental phobias in adult patients. The dentist’s role is to lessen dental anxiety by providing a pain-free procedure. This could be achieved by using painless procedures in caries removal such as air abrasion, laser, chemo-mechanical, enzymatic techniques, as well as the use of polymer or ceramic burs. Ceramic burs are rotary cutting instruments made of alumina-yttria stabilized zirconia round burs. They work by selective removal of carious infected dentin consequently avoiding pain which could be more appropriate for very young children.The aim of this study was to assess the extent of pain perception using ceramic burs during caries removal without local anesthesia in pediatric patients. This was performed on 51 patients between 4-8 years of age with 2 primary molars showing dentinal caries requiring class I restoration. The first visit (group I) caries was removed by ceramic bur on low speed hand-piece without administration of local anesthesia then the second visit (group II) caries was removed by carbide round bur on low speed hand-piece without administration of local anesthesia. During each procedure, objective assessment for pain was performed using FLACC scale. Upon completion, the pain threshold for caries removal was measured subjectively by Wong Baker faces pain rating scale. The various responses were gathered and subjected to statistical analysis. It was concluded that ceramic burs reduce the pain sensation during removal of infected dentin which ensures excellent patient comfort. There could be some advantages in using the ceramic bur: high acceptance by the patient, reduced pain response and sound pulp protection in deep caries lesions.

Comparative study of resin sealant and resin modified glass ionomer as pit and fissure sealant

The purpose of the present study was to compare the marginal integrity of resin modified glass ionomer cement with that of resin sealant, in vitro. Forty artificial pit and fissure cavities were prepared in occlusal surface of extracted premolar teeth by using ¼ round carbide bur. Cavities were condensed with artificial organic debris followed by cleaning with prophylaxis pumice brush and paste and then separated into two treatment groups. In Group A, 15 fissure cavities were sealed by resin sealant and in Group B, 15 fissure cavities were sealed by resin modified glass ionomer sealant. These specimens were subjected to thermo-cycling followed by dye penetration test. The remaining 5 cavities from each group were analyzed for debris score by the SEM. The results of the microleakage test showed that the efficacy of preventing microleakage of samples sealed by resin modified glass ionomer sealant was higher than the samples sealed by resin sealant. However, no significant differences were found. It can be concluded that use of resin modified glass ionomer sealant is a good alternative for sealing pits and fissures.

Dentinogenic Responses after Direct Pulp Capping of Miniature Swine Teeth with Biodentine

IntroductionThe aim of this study was to evaluate pulpal responses after experimental direct pulp capping of mechanically exposed teeth with a new calcium silicate–based dentin replacement material. MethodsThirty-four anterior and posterior teeth of 3 miniature swine were used. Class V or I cavities were prepared on the buccal or occlusal surfaces, respectively. Pulpal exposures were further performed using a round carbide bur 0.8 mm in diameter. Exposures were treated with white MTA Angelus (Angelus, Londrina, PR, Brazil) or Biodentine (Septodont, Saint Maur des Fosses, France), and the cavities were further restored with Biodentine. The pulpal tissue responses were histologically assessed at postoperative periods of 3 and 8 weeks. Data were statistically analyzed using the Kruskal Wallis and the Mann-Whitney U tests. ResultsInflammatory infiltration or pulp tissue necrosis was not found in any of the specimens. All teeth showed mineralized matrix formation in the form of a complete hard tissue bridge composed of osteodentin or osteodentin followed by a discontinuous or continuous reparative dentin zone. A significantly higher thickness of the hard tissue bridge was found in the group of teeth treated with Biodentine at both 3 and 8 weeks. A number of teeth, which were under root development at the onset of the experimental procedures, exhibited ectopic pulp calcification. ConclusionsThe application of both calcium silicate–based materials in direct contact with the mechanically exposed pulp of healthy miniature swine teeth led to pulp repair with complete hard tissue bridge formation. The thickness of hard tissue bridges was significantly higher after pulp capping with Biodentine.

Comparison of Pulp Stump Wounds Created by ProFile Rotary Root Canal Instruments and Small-diameter Fine Diamond Burs

IntroductionThe aim of this investigation was to evaluate and compare the pulp stump wounds created by the following root canal instruments: ProFile rotary files and small-diameter fine diamond burs. MethodsExtracted mandibular premolars from adult patients with vital pulps and fully formed root canals were collected and stored in formalin. Within 48 hours of extraction, the periapical tissue was fixated to the root with a double coating of ethyl cyanoacrylate, and the pulp chambers were accessed with a #4 round carbide bur and high-speed handpiece in a traditional fashion. The pulp tissue of 10 specimens per group was extirpated at a level approximately 5 mm from the apex by using standard endodontic techniques. The specimens were then examined at ×100 magnification under a digital microscope. Grading criteria were developed, and the wounds were scored. ResultsWounds created by diamond burs were significantly smoother that those created by ProFile rotary files; the mean wound score for diamond burs was 1.4 versus a mean wound score of 3 for ProFiles. After the author's scoring of the wounds, 2 endodontist graders were shown photos of each specimen in a double-blind fashion and instructed to score each specimen as being smooth or rough. To validate the developed scoring system and remove potential observer bias of the author, the data from the double-blind observations were used to complete a cross-tabulation for a Cohen kappa test. ConclusionsKappa values demonstrated substantial inter-rater agreement for both groups.

The Effect of Different Bracket Base Cleaning Method on Shear Bond Strength of Rebonded Brackets

To assess the effect of different bracket base conditioning method on shear bond strength (SBS) of rebonded brackets. Eighty brackets were bonded to freshly extracted premolar teeth using light cured composite adhesive. SBS was measured for 20 random samples as control group (G1). After debonding, 60 debonded brackets were allocated randomly into three groups of bracket base conditioning methods to remove the remaining adhesives. G2: bracket base cleaned with slow speed round carbide bur (CB), G3: cleaned with ultrasonic scaler (US), G4: cleaned with sandblasting (SB). After that, brackets were rebonded in the same manner as frst bonding and SBS was measured. Modifed adhesive remnant index (ARI) was recorded for all groups. SBS for new brackets was 11.95 MPa followed by 11.65 MPa for G2, 11.56 MPa for G4 and 11.04 MPa for G3 group. There were no statistically signifcant differences between all groups (p = 0.946). In all groups, failure mode showed that the majority of adhesive composite remained on the bracket base with ARI of 4. There was no statistically signifcant difference between all groups in ARI (p = 0.584). In-offce methods; slow speed CB and US are effective, quick and cheap methods for bracket base cleaning for rebonding.

A Comparative Histological Study of Bone Healing in Rat Calvarial Defect Using the Erbium-Doped Yttrium Aluminum Garnet Laser and Rotary Instruments

Erbium-doped yttrium aluminum garnet (Er:YAG) lasers have been used in dentistry for cutting bone and removal of caries. The purpose of this study was to evaluate the bone healing in a skull defect prepared in rats using various instruments including Er:YAG laser. The 7 mm calvarial defects were created in 45 rats and 45 rats were divided into three groups (n = 15): a high-speed rotation engine with carbide round bur (2-mm diameter), a low-speed rotation engine with carbide round bur (2-mm diameter), and an Er:YAG laser. Specimens obtained after 3 days or 4 or 8 weeks were submitted for histological analysis. Three days after surgery, no bone formation had occurred in any of the groups. Four weeks after surgery, 90 ±8.16% new bone formation was observed in the high-speed group, and 8 weeks after surgery, 100 ±0% new bone formation was observed in the low- and high-speed groups. There were significant differences among the periods after surgery, but no significant differences were observed among final results with in different device groups.

A comparative evaluation of dentin caries removal with polymer bur and conventional burs—An &amp;lt;i&amp;gt;in vitro&amp;lt;/i&amp;gt; study

Aim: To evaluate the comparative efficacy of Polymer bur (Smartprep) and Conventional burs (Carbide bur & Diamond Points) in selective Dentin caries removal. Materials and method: 15 freshly extracted carious human premolars and molars were selected for this study. These teeth were split in the center of carious lesion, in order to obtain two corresponding half. Thus 30 samples were prepared in this way. These were randomly divided in to 3 groups of 10 samples each. Group 1: The carious portion of these samples was excavated with the help of polymer bur Smartprep (SS White). Group 3: Prepared with Tungsten carbide round bur (No. 018). Group 3: Prepared with the help of Diamond points (No. 018). The period of time involved in this process is measured. After excavation of all carious lesions, a longitudinal section from mid most part of lesion was obtain with the help of diamond disc at slow speed. After staining with caries detector dye “Seek”, the sections were subjected to histological evaluation under stereomicro-scope. The thickness of remaining caries is measured in more or less than 1 mm. Results: The difference in grading of remaining carious dentin between Polymer bur and Conventional burs were statistically non- significant, but Polymer bur taken more time in comparison to Conventional burs. Conclusion: Smartprep bur is more conservative in selectively dentin caries removal than Conventional burs but same time it is more time consuming than Conventional burs.

Evaluation of the feasibility of bony window repositioning without using a barrier membrane in sinus lateral approach

Introduction: In the lateral window approach for a maxillary sinus bone graft, there has been considerable controversy regarding the placement of a barrier membrane over the osteotomy site. In particular, when there is no damage to the Schneiderian membrane, clinicians should decide whether to use a barrier membrane or not, considering the benefits and costs. This study presents the clinical cases to demonstrate that only repositioning the detached window can lead to satisfactory bony healing of the grafted material without using a barrier membrane in the lateral approach for a maxillary sinus bone graft. Materials and Methods: Five consecutive patients were treated with the same surgical procedures. After performing the antrostomy on the lateral maxillary wall using a round carbide bur and diamond bur, the bony window was detached by a gentle levering action. After confirming no perforation of the Schneiderian membrane, the grafting procedure was carried out the detached window of the lateral maxillary wall was repositioned over the grafted material without using a barrier membrane. A gross examination was carried out at the postoperative 6 month re-entry, and the the preoperative and postoperative dental computed tomography (CT) at re-entry were compared. Results: All the procedures in the 5 patients went on to uneventful healing with no complications associated with the bone graft. Satisfactory bone regeneration without the interference of fibrous tissue on the gap between the repositioned window and lateral wall of the maxillary sinus was observed in the postoperative 6 month re-entry. The CT findings at re-entry revealed the, reconstruction of the external cortical plate including repositioned bony window. In addition, the loss of the discontinuity of the lateral maxillary wall was confirmed. Conclusion: This preliminary report showed that the detached window, which was just repositioned on the grafted material, could function as a barrier membrane in the lateral approach for a maxillary sinus bone graft. Therefore additional morphometric and histologic studies will be needed.

Titanium-Reinforced Polytetrafluoroethylene Membrane Combined with Inorganic Polyphosphate Induces Exophytic Bone Formation in Rabbit Calvaria

The purpose of this study was to examine if the application of titanium-reinforced expanded polytetrafluoroethylene(TR-ePTFE) membrane combined with bovine bone mineral(BBM) soaked in inorganic polyphosphate promotes exophytic bone formation in rabbit calvaria. For this purpose, a total of 8 rabbits were used, and rectangular decorticated calvaria sites were created using a round carbide bur. In the control group, rectangular parallelepiped-shaped TR-ePTFE membranes (RPTPMs) were filled with BBM soaked in saline and placed on the decorticated sites and fixed with metal pins. In the experimental groups, RPTPMs were filled with BBM soaked in 4%, 8% and 16% inorganic polyphosphate prior to fixing with metal pins. Animals were sacrificed at 4 and 8 weeks after surgery, and new bone formation was assessed by histomorphometric as well as statistical analysis. The results indicated that at 8 weeks, all the experimental groups demonstrated exophytic bone formation. At 8 weeks, the 8% polyphosphate group revealed the most new bone formation (p&lt;0.05). On the basis of these findings, we conclude that inorganic polyphosphate has a promoting effect on bone regeneration, possibly by enhancing osteoinductivity of the decorticated wound area and osteoconductivity of the carrier material, but not much as we expected.

Porous Titanium Membranes Combined with Various Graft Materials Induce Exophytic Bone Formation in Rabbit Calvaria

The purpose of this study was to examine if the application of custom-made porous titanium membranes combined with bone graft materials promotes exophytic bone formation in rabbit calvaria. For this purpose, round decorticated calvaria sites were created using a round carbide bur. In the control group, rectangular parallelepiped-shaped porous titanium membranes (RPTMs) were placed on the decorticated sites and fixed with metal pins. In the experimental groups, RPTMs were filled with one of the following bone graft materials prior to fixing with metal pins: bovine bone mineral (BBM), demineralized freeze-dried human cortical bone (DFDB) or freeze-dried human cancellous bone (FDB). Animals were sacrificed at 8 and 12 weeks after surgery, and new bone formation was assessed by histomorphometric as well as statistical analysis. The results indicate that at 8 and 12 weeks, all the experimental groups demonstrated exophytic bone formation. At 12 weeks, DFDB group revealed the most new bone formation (p&lt;0.05) and resorption of grafted materials (p&lt;0.05). On the basis of these findings, we conclude that RPTMs may be used as an augmentation membrane for guided bone regeneration and DFDB as an effective bone-inducing graft material.

Retrospective Evaluation of Surgical Endodontic Treatment: Traditional versus Modern Technique

The aim of this retrospective study was to compare the outcome of surgical endodontic treatment preformed using the traditional versus modern techniques. There were 110 patients who were treated by surgical endodontic treatment between 2000 and 2002 and evaluated from their dental charts. The surgical endodontic treatment was preformed using a traditional or modern technique. The traditional technique included root-end resection with a 45 degrees bevel angle, and retrograde preparation using a carbide round bur. The modern technique included root-end resection with minimal or no bevel, and retrograde preparation using ultrasonic retro-tips with the aid of a dental operating microscope. The retrograde filling material for both techniques was intermediate restorative material. There were 71 patients with 88 treated teeth that were compatible with the inclusion criteria. Complete healing rate for the teeth treated with the modern technique (91.1%) was significantly higher than that for teeth treated using the traditional technique (44.2%) (p < 0.0001). In the traditional technique a significant (p = 0.032) negative influence of the tooth type was found. Modern surgical endodontic treatment using operative microscope and ultrasonic tips significantly improves the outcome of the therapy compared to the traditional technique.