Kerem Engin Akpınar

Apical extrusion of intracanal debris and irrigant following use of various instrumentation techniques

OBJECTIVE The purpose of this study was to compare in vitro the amount of debris and irrigant extruded apically from extracted teeth, using manual technique and crowndown pressureless technique by K3, RaCe, and FlexMaster instruments. STUDY DESIGN Sixty human single-rooted mandibular premolar teeth were randomly assigned to 4 groups, 15 teeth each. The teeth in 4 groups were instrumented until the working length with RaCe, K3, FlexMaster, and K-type stainless steel instruments respectively. Debris and irrigant extruded from the apical foramen were collected into vials and the amounts were determined. The data obtained were analyzed using Kruskal-Wallis 1-way analysis of variance and Mann-Whitney U tests, with alpha = 0.05 as the level for statistical significance. RESULTS No statistically significant difference was observed among the groups in terms of debris extrusion (P > .05). On the other hand, a statistically significant difference was observed between K3 and manual technique groups in terms of irrigant extrusion (P < .05). The difference between other groups was not statistically significant (P > .05). CONCLUSION Based on the results, all instrumentation techniques produced extruded debris and irrigant; however, the engine-driven nickel-titanium systems were associated with less apical extrusion and irrigant.

Apical extrusion of intracanal bacteria following use of various instrumentation techniques

AIM To evaluate the number of bacteria extruded apically from extracted teeth ex vivo after canal instrumentation using a manual technique and three engine-driven techniques utilizing nickel-titanium instruments (K3, RaCe, and FlexMaster). METHODOLOGY Seventy extracted human mandibular premolar teeth with similar dimensions were used. Access cavities were prepared and root canals were then contaminated with a suspension of Enterococcus faecalis and then dried. The contaminated roots were divided into four experimental groups of 15 teeth each and one control group of 10 teeth. G1. RaCe group: the root canals were instrumented using RaCe instruments. G2. K3 group: the root canals were instrumented using K3 instruments. G3. FlexMaster group: the root canals were instrumented using FlexMaster instruments. G4. Manual technique group: the root canals were instrumented using K-type stainless steel instruments. G5. CONTROL GROUP no instrumentation was attempted. Bacteria extruded from the apical foramen during instrumentation were collected into vials. The resultant microbiological samples were removed from the vials and then incubated in culture media for 24 h. The number of colony-forming units (CFU) was determined for each sample. The data obtained were analysed using the Kruskal-Wallis one-way analysis of variance and Mann-Whitney U-tests, with alpha = 0.05 as the level for statistical significance. RESULTS There was a significant difference between experimental-control and engine-driven-manual technique groups (P < 0.05). The manual technique was associated with the greatest extrusion of microorganism. CONCLUSIONS All instrumentation techniques extruded intracanal bacteria apically. No significant difference was found in the number of CFU among the engine-driven techniques; manual techniques extruded significantly more microorganisms.

Effect of gingiva on laser doppler pulpal blood flow measurements.

The purpose of this study was to evaluate the effect of labial and palatinal gingiva on laser Doppler pulpal blood flow measurements. Twenty upper central incisor teeth determined to be vital from 20 volunteers were included into the study. To stabilize the probe, a laboratory-made acrylic splint positioned the probe labially on the cervical third of the tooth crown. We collected measurements without any gingival covering, and under three conditions: after application of an opaque paste on the labial gingiva, the palatal gingiva, or both the labial and palatal gingiva. The measurement values decreased 46% when there was opaque paste on labial gingiva, 10% on palatinal gingiva, and 63% on both. The decrease in the values when there was an opaque paste on palatinal gingiva was not statistically significant (p > 0.05). The differences between all other groups were statistically significant (p < 0.05). In these measurements, the contribution of labial gingiva to laser Doppler pulpal blood flow measurements is more than that of palatinal gingiva.

The sources of laser Doppler blood-flow signals recorded from vital and root canal treated teeth

OBJECTIVES The aim was to determine the strength of signals derived from the dental pulp and those from the surrounding tissues in human teeth using the laser Doppler flowmetry (LDF). METHODS Twenty-six vital teeth (13 experimental and 13 controls) from 12 patients were used. Experimental teeth had root canal treatment in a single visit and their healthy antimeres were controls. Blood flow measurements were made before and after local anaesthesia, after root canal preparation, following root canal filling and coronal restoration. RESULTS Perfusion unit (PU) values recorded from empty pulp chamber were determined to be only 30% lower than the values recorded before anaesthesia from the experimental intact teeth. When the measurements in the group were compared with each other the values of variation in the both groups were not statistically significant. The variation between the groups when the measurement values before anaesthesia, 10min after anaesthesia and after coronal restoration were compared, it was not statistically significant (P>0.05). The variation between the groups after preparation and root canal filling in their values of measurements was important statistically (P<0.05). The measurement values of the study group were lower than that of the control group. CONCLUSIONS In pulpal, LDF a major portion of the signal comes from tissues other than pulp. Without taking precautions (such as rubber-dam application) in pulp blood flow measurements, the results may be inconsistent.

The efficacy of two rotary NiTi instruments and H-files to remove gutta-percha from root canals.

Objective: The aim of this study was to evaluate the efficacy of R-Endo® and K3® rotary nickel-titanium instruments compared with manual instrumentation with H-files, with use of a solvent, for removal of gutta-percha during retreatment. Study design: Forty five freshly extracted human single-rooted teeth, each with one root canal, were instrumented with K-files and filled using cold lateral compaction of gutta-percha and AH 26® sealer. The teeth were randomly divided into three groups of 15 specimens each. Removal of gutta-percha was performed with the following devices and techniques: Group 1 (H-files), Group 2 (R-Endo®), and Group 3 (K3®). The specimens were rendered transparent for the evaluation of the area of remaining gutta-percha/sealer in buccolingual and mesiodistal directions. Statistical analysis as performed by using one-way ANOVA and Kruskal-Wallis tests (p=0.05). Results: All retreatment techniques used in this study left some filling material inside the root canal. Images in buccolingual and mesiodistal directions showed no significant differences between the groups (p>0.05). Conclusions: Under the experimental conditions, the remaining filling material after retreatment was similar for each group. Key words:Gutta-percha removal, K3®, NiTi, R-Endo®.

MAXILLARY FIRST PREMOLARS WITH THREE ROOT CANALS: TWO CASE REPORTS

It is very important that the dentists have sufficient information about possible variations in the expected root canal configurations in order to achieve success in endodontic treatment. In addition to having adequate knowledge on the variations of the root canal anatomy, periapical radiographs from different angles, careful examination of the pulp chamber floor, and use of dental operation microscope during the procedure are also important factors that contribute to the diagnosis of the additional roots and canals. The aims of this article are to present the diagnostic approach and root canal treatments of two maxillary first premolar teeth with three canals in two patients.

Mtwo ve S5 NiTi döner kanal eğelerinin yapay kök kanalını şekillendirme etkinliklerinin karşılaştırılması

AMAC: Bu calismanin amaci, Mtwo ve S5 nikel-titanyum doner kanal egelerinin yapay egri kanallari sekillendirme etkinliklerinin karsilastirilmasidir. GEREC ve YONTEM: Kirk adet yapay kanal rastgele iki gruba ayrildi (n=20). Kanallar Mtwo ve S5 egelerle apikal cap 30’a kadar sekillendirildi. Dijital kamera kullanilarak elde edilen preoperatif ve postoperatif kanal goruntuleri birlestirildi ve normalden sapmalar kaydedildi. Madde kaldirma 5 farkli noktada olculdu. Istatistiksel degerlendirme 0.05 anlamlilik duzeyinde Kolmogorov-Smirnov testi, independent t-testi ve ki-kare testi kullanilarak yapildi. BULGULAR: Kanallarin ortalama toplam genislikleri, sekillendirmenin apikal son noktasi haric Mtwo grubunda S5 grubundan anlamli olarak daha fazlaydi (p 0.05). SONUC: Mtwo daha genis kanal sekli ortaya koydu. S5 daha merkezi bir apikal sekillendirme sagladi ve orijinal kanal seklini daha iyi korudu.

İki Farklı Döner Nikel-Titanyum Preparasyon Sistemi Ve İki Farklı El Preparasyon Sisteminin Eğimli Kök Kanallarının Şekillendirilmesindeki Etkinliklerinin Karşılaştırılması

Amac: Bu calismanin amaci, Quantec LX ve Profile 29 doner NiTi enstrumanlar ve Nitiflex ve paslanmaz celik el enstrumanlarinin egri kanallardaki etkinliginin karsilastirilmasidir. Gerec ve Yontem: Bu calismada 25-40° kurvatur acisina sahip 48 adet mandibular molar dise ait mesial kanallar, her biri 12 kanal icerecek sekilde 4 gruba ayrildi. Preparasyon gruplari olarak Nitiflex ve H tipi el enstrumanlari, Profile 29 ve Quantec LX doner NiTi enstrumanlar kullanildi. Calismanin sonunda kanal egiminde ve calisma boyunda meydana gelen degisiklikler, alet kiriklari ve perforasyonlar kaydedildi. Verilerinin istatistiksel olarak degerlendirilmesinde Wilcoxon eslestirilmis iki ornek testi, Kruskal-Wallis ve Mann Whitney-U testleri kullanildi. Bulgular: Doner NiTi preparasyon sistemlerinin kanal egiminde ve calisma boyunda paslanmaz celik kanal egelerine gore daha az degisime neden oldugu saptandi. Paslanmaz celik ve Nitiflex kanal egelerinde alet kirigi saptanmadi. Doner NiTi preparasyon sistemlerinde lateral perforasyonlar gorulurken, paslanmaz celik kanal egesi kullanilan grupta ise strip perforasyonlar saptandi. Sonuclar: Sonuc olarak, doner NiTi preparasyon sistemlerinin egri kok kanallarini, elle kullanilan preparasyon sistemlerine gore daha etkili bir sekil