Contact Angle Measurement of Dental Restorative Materials by Drop Profile Image Analysis

The capability of initial microbial adhesion to dental restorative composites surface is influenced by the surface wettability of the materials. The common method to evaluate surface wettability of materials is contact angle measurement. The existing conventional method to measure contact angle is by means of a contact angle (CA)-Goniometer device, which is less practically applicable in clinical circumstances. Therefore, a more practical and applicable method is needed to measure contact angle in clinical circumstances. This research was performed to compare between contact angles measured by means of a CA-Goniometer device and a new practical method of drop profile image analysis. In addition, since there were two different formulas that can be used to calculate contact angle value from a drop profile image, then we also need to evaluate which formula is more reliable to be used. Tests were carried out using three composite discs (Clearfill-Kuraray Medical, Inc.) sample and deionised water for different measurement procedures. One drop of 3µl liquid was dropped onto the surface of the composite discs, and the drop profile image was captured by means of a customized home-made device connected to a digital camera. Two different formulas were used to calculate the contact angle value from the drop profile image, namely the “linier gradient equation” and the “tangential line”. The contact angle values obtained from the two different formulas were compared with the value obtained from the conventional method descriptively. Tests were carried out using three composite discs (Clearfill-Kuraray Medical, Inc.) sample and deionised water for different measurement procedures. One drop of 3µl liquid was dropped onto the surface of the composite discs, and the drop profile image was captured by means of a customized home-made device connected to a digital camera. Two different formulas were used to calculate the contact angle value from the drop profile image, namely the “linier gradient equation” and the “tangential line”. The contact angle values obtained from the two different formulas were compared with the value obtained from the conventional method descriptively. The differences in percentage between the contact angle value calculated by the “linier gradient equation” and “tangential line” formulas, and those calculated by means of the CA-Goniometer are 20,56% and 3,51%, respectively. It is obviously demonstrated that the value obtained by the “tangential line” formula has a smaller difference compared to those obtained by the “linier equation gradient” formula. Among the two different formulas, it is confirmed that the contact angle value calculated with the “tangential line” formula has closer similarity with the value obtained from the CA-Goniometer. This result confirms that the new practical method of drop profile image analysis is promising for measuring contact angle values in clinical circumstances. Related to the drop profile image analysis, the “tangential line” formula is more accurate compared to the “linier gradient equation” formula

Effect of nanofilled self-adhesive protective coating on color changes and surface roughness of composite resin

Background: Discoloration of composite restorations may affecting aesthetic appearance. The aging-process and surface roughness may influence color changes. A nanofilled self-adhesive protecting coating has been developed for coating tooth restoration and expected to prolong the longevity of restoration. To evaluate the effect of nanofilled self-adhesive protective coating on the surface roughness and color-changes of flowable and packable composite after aging condition. Methods: The total of 40 discs (15x2mm) and 60 boxes (20×10× 2mm) specimens from flowable and packable composite were used. A half of the specimens was coated by using protective-coating. The reflectance chromameter was used to measure the color baseline. Afterward, the specimens were subjected into aging process by immersing in artificial saliva and carbonated drink (37oC,7d). The color changes were calculated based on the [CIE L*a*b*].For surface roughness, box-shaped specimens were measured in fresh condition, after aging conditions. Results: The color change ranged from 0.49 to 2.31. Applying protective-coating was associated with a significant decrease in the color-changes and surface roughness after aging. The changes of three color coordinates resulted in significant differences for both composite, with and without protective coating application. Conclusion: The application of protective-coating decrease the color-changes and surface roughness of flowable and packable composite-resin

Comparison of fracture resistance of teeth with prepared protaper next, protaper gold, and hyflex CM rotary files

Preparation of the root canal system is a crucial step in root canal treatment. Endodontically treated teeth differ structurally from healthy, untreated teeth. This can lead to root cracking by creating pressure on the canal wall, reducing the fracture resistance of the tooth. Different designs, including cross-sectional shape, tip, taper, flute, radial land, helix angle, rake angle, and pitch, can influence the outcome of the root canal preparation and the risk of root fracture. The purpose of this study was to evaluate the fracture resistance of teeth after root canal preparation using three different NiTi rotary files: ProTaper Next (PN), ProTaper Gold (PG), and HyFlex CM (HC). Thirty premolars with a single and straight root canal were decoronated at the cementoenamel junction, leaving 14 mm of the root. The subjects were divided into 3 groups. Group 1 (n = 10) was prepared using PN, group 2 (n = 10) was prepared using PG, and group 3 (n = 10) was prepared using HC. After instrumentation and irrigation, the specimens were subjected to a continuous vertical compressive force (crosshead-speed of 2.28 mm/sec) in order to record the force (in newtons) until root fracture. To describe the surface characteristic of the dentinal root after the preparation, a section fragment from the apical third of the specimens was observed using a scanning electron microscope (SEM) at 2500x magnification. The micrographs were analyzed according to the Hulsman’s method. The results demonstrated that there was a statistically significant difference in root fracture resistance among the three groups. (p = 0.043). The LSD post hoc test indicated that HC showed a higher root fracture resistance (p < 0.05) compared to both PN and PG. In conclusion, the different file systems of PN, PG, and HC instruments generate different root fracture resistance of teeth. In comparison to PN and PG, HC instruments tend to result in increased fracture resistance

CONTACT ANGLE MEASUREMENT OF DENTAL RESTORATIVE MATERIALS BY DROP PROFILE IMAGE ANALYSIS

The capability of initial microbial adhesion to dental restorative composites surface is influenced by the surface wettability of the materials. The common method to evaluate surface wettability of materials is contact angle measurement. The existing conventional method to measure contact angle is by means of a contact angle (CA)-Goniometer device, which is less practically applicable in clinical circumstances. Therefore, a more practical and applicable method is needed to measure contact angle in clinical circumstances. This research was performed to compare between contact angles measured by means of a CA-Goniometer device and a new practical method of drop profile image analysis. In addition, since there were two different formulas that can be used to calculate contact angle value from a drop profile image, then we also need to evaluate which formula is more reliable to be used. Tests were carried out using three composite discs (Clearfill-Kuraray Medical, Inc.) sample and deionised water for different measurement procedures. One drop of 3µl liquid was dropped onto the surface of the composite discs, and the drop profile image was captured by means of a customized home-made device connected to a digital camera. Two different formulas were used to calculate the contact angle value from the drop profile image, namely the “linier gradient equation” and the “tangential line”. The contact angle values obtained from the two different formulas were compared with the value obtained from the conventional method descriptively. Tests were carried out using three composite discs (Clearfill-Kuraray Medical, Inc.) sample and deionised water for different measurement procedures. One drop of 3µl liquid was dropped onto the surface of the composite discs, and the drop profile image was captured by means of a customized home-made device connected to a digital camera. Two different formulas were used to calculate the contact angle value from the drop profile image, namely the “linier gradient equation” and the “tangential line”. The contact angle values obtained from the two different formulas were compared with the value obtained from the conventional method descriptively. The differences in percentage between the contact angle value calculated by the “linier gradient equation” and “tangential line” formulas, and those calculated by means of the CA-Goniometer are 20,56% and 3,51%, respectively. It is obviously demonstrated that the value obtained by the “tangential line” formula has a smaller difference compared to those obtained by the “linier equation gradient” formula. Among the two different formulas, it is confirmed that the contact angle value calculated with the “tangential line” formula has closer similarity with the value obtained from the CA-Goniometer. This result confirms that the new practical method of drop profile image analysis is promising for measuring contact angle values in clinical circumstances. Related to the drop profile image analysis, the “tangential line” formula is more accurate compared to the “linier gradient equation” formula

PRA PERANCANGAN PABRIK DIMETIL FORMAMIDA DARI METIL FORMAT DAN DIMETILAMINA KAPASITAS 14.500 TON/TAHUN

Pabrik dimetil formamida dengan bahan baku metil format dan dimetilamina dirancang dengan kapasitas 14.500 ton/tahun akan didirikan di Kecamatan Manyar, Kabupaten Gresik dengan luas lahan 7,74 hektar. Waktu operasi pabrik selama 330 hari/tahun. Proses pembuatan dimetil formamida terdiri dari 3 tahapan, yaitu proses persiapan bahan baku, proses reaksi, dan proses pemisahan. Bahan yang digunakan dalam pembuatan dimetil formamida adalah metil format dengan kemurnian 97% dan dimetil amin yang menggunakan proses kontinyu. Proses reaksi yang terjadi antara metil format dan dimetilamin bersifat eksotermis dan irreversible. Pada proses reaksi digunakan Reaktor Alir Tangki Berpengaduk (RATB) yang bekerja pada suhu 110˚C dan tekanan 3,46 atm dengan konversi reaksi sebesar 90%. Pemisahan dilakukan sebanyak 2 kali, dimana yang pertama untuk mendapatkan produk samping berupa metanol dengan sisa bahan metil format, dan yang kedua untuk menghasilkan produk utama Dimetil formamide dengan kemurnian 99,7%. Total karyawan yang dibutuhkan untuk mengoperasikan pabrik ini berjumlah 218 orang dengan tiga shift. Berdasarkan Analisa ekonomi didapat laju pengembalian modal atau Pay Out Time (POT) selama 2,52 tahun dengan presentase Break Even Point (BEP) sebesar 40%. Kata kunci Dimetil Formamida, Metil Format, Dimetilamin

Impregnation of various fiber tapes toward mechanical properties of dental fiber-reinforced composites

Synthetic dental fiber tape for fiber reinforcement (FRC) restoration is relatively costly and its availability is still limited in Indonesia, so natural dental fibers have been used as an alternative material. The aim of this study was to assess the effect of impregnation of various fiber tape toward the flexural strength and hardness of FRC. The materials used were natural Bombyx mori silk fibers (Indonesia), dental polyethylene tape (Construct Kerr, USA), dental Quartz tape (Quartz Splint UD, France), dental E-glass tape (Everstick TM, GC, Japan), silane coupling agent (Ultradent, Jordan), and composite resin (Denfil-Flow, USA). Five groups of samples consisted of FRC with various fiber tapes were prepared: unidirectional-silk, braided-silk, quartz, polyethylene, and E-glass. The five groups of FRC were tested to determine the flexural strength and hardness. The results were analyzed by one-way ANOVA, followed by LSD test. The results showed that the highest flexural strength was in the quartz group (496.84 ± 109.14 MPa), while the lowest was in the braided-silk group (139.39 ± 4.30 MPa). The highest hardness property was in the unidirectional-silk group (141.29 ± 25.17 VHN), while the lowest was in the braided-silk group (139.39 ± 4.30 VHN). The ANOVA showed that various fiber tapes significantly influenced the flexural strength and hardness of FRC (p < 0.05). The LSD showed that the unidirectional-silk, braided-silk, and polyethylene groups demonstrated no significant difference. The LSD for hardness showed that the unidirectional-silk group had a significant difference with the other groups (p < 0.05). It can be concluded that various fiber tapes influenced the flexural strength and hardness of FRC. Natural silk fibers showed comparable flexural strength and hardness with the other fiber tapes

THE EFFECT SODIUM HYPOCHLORITE 2,5% AND SODIUM THIOSULPHATE AS IRRIGATION ON THE CLEANLINESS OF THE APICAL THIRD ROOT

Background: Sodium hypochlorite produces free oxygen and free radicals that cause damage to dentin collagen. Combination with Sodium thiosulfate with the aim of improving root canal hygiene and restoring the oxidizing effect on the dentin surface.The apical third of the root canal is the most difficult part, due to its narrower anatomy, curvature and frequent branching of the root canal. Method: The study used 30 specimens which were divided into 3 groups, group I was irrigated with 2.5% NaOCl, 5% sodium thiosulfate and saline, group II was irrigated with 2.5% NaOCl, 10% sodium thiosulfate and saline and group III was irrigated with 2.5% NaOCl and saline. The tooth length 14 mm measured from apical to crown. The crown down technique was prepared using the M3 Pro gold file. Observation of the level of cleanliness of the root canal was carried out using a Scanning Electron Microscope (SEM) with 5000x magnification at apical third . The results of micrographic photographs are then given a score of 1-4.Result: Irrigated with 5% and 10% sodium thiosulfate showed no significant difference.Conclusion: The differences is not significant, 2,5% irrigation with sodium thiosulfate resulted in a higher cleanliness apical third of the root canalthan 2,5% NaOCl irigation with salin

Pengaruh pasta gigi fluorida dan low-abrasive fluoridated terhadap kekasaran permukaan gigi pasca home bleaching karbamid peroksida 20%

Bleaching merupakan prosedur pemutihan gigi yang pada saat ini banyak diminati oleh masyarakat. Salah satu efek bleaching adalah terjadinya peningkatan porusitas email sehingga gigi lebih rentan terhadap terjadinya karies. Remineralisasi diperlukan untuk meningkatkan kekerasan email, salah satunya dengan pemberian pasta gigi. Terdapat beberapa jenis pasta gigi yang beredar di pasaran, namun belum diketahui pasta gigi manakah yang terbaikuntuk digunakan pada pasien pasca bleaching. Penelitian ini bertujuan untuk mengetahui pengaruh penggunaan pasta gigi fluorida dan pasta gigi low-abrasive fluoridated terhadap karakteristik permukaan gigi pasca aplikasi home bleaching menggunakan karbamid peroksida 20%. Penelitian ini menggunakan spesimen berupa 20 gigi premolar rahang atas yang sudah dilakukan ekstraksi, kemudian diberi perlakuan penyikatan dengan akuades, pasta giginonfluorida, pasta gigi fluorida, dan pasta gigi low-abrasive fluoridated. Uji kekasaran permukaan dilakukan sebelum bleaching, setelah bleaching, serta penyikatan setelah bleaching. Hasil uji ANAVA dua jalur menunjukkan nilai p < 0,05 maka terdapat perbedaan yang signifikan pada kelompok perlakuan penyikatan gigi dan kelompok waktu pengujian kekasaran permukaan. Uji post-hoc multiple comparison test LSD menghasilkan terdapat perbedaaan kekasaran permukaan gigi yang bermakna antara kelompok penyikatan gigi dengan pasta gigi fluorida dan pastagigi low-abrasive fluoridated. Proses bleaching pada penelitian ini menunjukkan peningkatan kekasaran permukaan email gigi secara signifikan. Perlakuan penyikatan gigi menurunkan kekasaran permukaan email secara bermakna. Berdasarkan hasil penelitian dapat diambil kesimpulan bahwa proses penyikatan dengan pasta gigi pasca bleaching dapat mengembalikan kondisi kekasaran permukaan email yang mendekati saat sebelum dilakukan bleaching.Penggunaan pasta gigi fluorida dan pasta gigi low-abrasive fluoridated direkomendasikan untuk digunakan pada pasien pasca perawatan bleaching