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Papers by Bur Han

Research paper thumbnail of Tooth Preparation: A Study on the Effect of Different Variables and a Comparison Between Conventional and Channeled Diamond Burs

Journal of Prosthodontics, 2004

Purpose: The purpose of this study was to evaluate the different variables involved in tooth cutt... more Purpose: The purpose of this study was to evaluate the different variables involved in tooth cutting to characterize intrapulpal temperature generation, cutting efficiency, and bur durability when using conventional and channeled diamond burs.Materials and Methods: Forty premolars and 60 molars were selected for the study. Four diamond burs were paired according to grit size: 125-μm grit: Brasseler Coarse (Control 1) and TDA System (Test 1) burs; and 180-μm grit: Brasseler CRF (Control 2) and NTI Turbo Diamond (Test 2) burs. Each bur was used twice when cutting the premolar teeth, whereas it was used for 60 cuts when cutting the molar teeth. The data were analyzed to compare the correlation of bur design, grit and wear, amount of pressure, advancement rate, revolutions per minute, cutting time and rate, and proximity to the pulp chamber with intrapulpal temperature generation, cutting efficiency, and bur longevity. The mean values of test and control burs in each group were compared using an ANOVA (p < 0.05 for significant differences) for temperature generation and an ANOVA and the Tukey multiple range test (p≤ 0.05) for cutting efficiency and bur longevity.Results: No significant difference was found in intrapulpal temperature generation while cutting premolar and molar teeth with conventional and channeled diamond burs. In both groups, the mean temperature recorded during and after the cutting procedure was lower than the baseline temperature. For premolar teeth, no significant difference was established for control and test burs for the load required to cut into the tooth and the cutting rate. However, both test burs showed significantly fewer revolutions per minute when compared to their control counterparts. For the molar teeth, the Brasseler CRF bur required a significantly lower cutting load when compared to the NTI bur, whereas no difference was noted between the other pair of burs. The cutting rate was significantly higher for both control burs, whereas revolutions per minute (rpm) were greater for control coarser burs only. Overall, channeled burs showed a significantly lower cutting efficiency when compared to conventionally designed burs.Conclusion: Within the limitations of this study, channeled burs showed no significant advantage over conventional diamond burs when evaluating temperature generation and bur durability. Moreover, the cutting efficiency of conventional burs was greater than that of channeled burs.

Research paper thumbnail of Conformational Analysis of 1,2:3,4-Diepoxides:Ab Initio and semiempirical molecular-orbital calculations

Helvetica Chimica Acta, 1992

Using semiempirical and ab initio procedures, the most stable conformations of meso- and rac-biox... more Using semiempirical and ab initio procedures, the most stable conformations of meso- and rac-bioxirane and of some substituted 1,2:3,4-diepoxides were calculated. For threo-diepoxides (having the same relative configurations as rac-bioxirane, 3), two stable conformations with CCCC dihedral angles of ca. 90 and ca. 270° were found. For erythro-diepoxides (derivatives of meso-bioxirane, 4) the calculations suggest three preferred conformations with corresponding dihedral CCCC angles of ca. 90°, ca. 180°, and ca. 270°. The calculations are in fair agreement with the experimental data available for the unsubstituted compounds 3 and 4.

Research paper thumbnail of Einfache methode fur den nachweis von Staphylokokken-Enterotoxin-B in vanillepudding mittels ELISA-test

European Food Research and Technology, 1981

The ELISA for the detection of staphylococcal enterotoxin type B (SEB) was employed to demonstrat... more The ELISA for the detection of staphylococcal enterotoxin type B (SEB) was employed to demonstrate SEB in Dutch Vanilla custard. Due to the sensitivity of the ELISA the extraction procedure, which is necessary when the Ouchterlony test is used, can be abbreviated to a great extent. Two successive extractions at pH 7.4 and pH 4.5 followed by a concentration (1:20) was sufficient to detect 0.1 mcg SEB in 100 g custard. Für den holländischen Vanillepudding (Vla) wurde der ELISA-Test zum Nachweis von Staphylokokken-Enterotoxin-B (SEB) geprüft. Dabei zeigte sich, daß die fur einen serologischen Nachweis (Ouchterlony-Test) notwendige Aufarbeitung weitgehend verkürzt, and damit der erforderliche Arbeitsaufwand entscheidend reduziert werden kann. Die Empfindlichkeit des ELISA-Tests reicht aus, um nach zwei aufeinanderfolgenden Extraktionen bei pH 7,4 und pH 4,5 and anschließender Konzentrierung (1:20) noch 0,1 mcg SEB in 100 g Probe nachzuweisen.

Research paper thumbnail of Phenol as an adjuvant for local control in the treatment ofgiant cell tumour of the bone

Ejso, 1999

Intralesional treatment of giant cell tumour (GCT) of the bone may result in a high rate of local... more Intralesional treatment of giant cell tumour (GCT) of the bone may result in a high rate of local recurrence. The introduction of local adjuvant therapy, such as cementation or phenolization, has lead to a significant reduction in recurrence rates. Due to the combined use of phenol and cementation in most studies, the effect of phenol alone is described in this study. Methods: Twenty primary and nine recurrent surgical procedures in 26 patients with GCT of the bone with a median follow-up of 61 months were reviewed retrospectively. The mean age was 33.5 years (range 13.5-76.5 years). Eighteen curettages and 11 resections were performed. For the curettages, a large bone window was cut followed by high speed burring and bone graft reconstruction. In 11 of 18 curettages and three of 12 resections, phenol was additionally applied. Results: Four patients showed pulmonary metastasis. Three of these four cases also experienced local recurrences. Three patients died due to metastatic disease. In total, five patients developed local recurrence (17.2%); three in the first 2 years and one after 4 years. Four of 18 curettages recurred (22.2%), compared to one of 11 resections (9.1%). Only one of 11 patients (9.1%) treated with curettage and adjuvant phenol recurred, whereas three of seven patients (42.9%) treated with curettage alone recurred. Conclusion: Phenolization is an effective and safe local adjuvant therapy for GCT. We did not observe any significant differences in recurrence rates for curettage, phenolization and bone grafting compared to most published results using cryosurgery or cementation alone. We recommend adjuvant phenolization in the treatment of GCT of the bone after careful curettage in applicable cases, regardless of whether additional cementation is used.

Research paper thumbnail of De Novo Design, Synthesis, and In Vitro Evaluation of a New Class of Nonpeptidic Inhibitors of the Malarial Enzyme Plasmepsin II

Research paper thumbnail of Hamstring graft fixation in MPFL reconstruction at the patella using a transosseous suture technique

Knee Surgery Sports Traumatology Arthroscopy, 2010

Controversy still exists about fixation methods of a hamstring graft to the patella in case of me... more Controversy still exists about fixation methods of a hamstring graft to the patella in case of medial patellofemoral ligament (MPFL) reconstruction. This article presents a surgical technique of hamstring tendon graft fixation to the anatomical MPFL insertion on the patella using transosseous sutures. A superficial bony sulcus is created at the anatomical MPFL insertion site on the medial patellar rim with a bur. A looped hamstring tendon graft is fixed to this superficial sulcus by a pair of nonresorbable transosseous sutures passed across the patella. The retinaculum is sutured on top of the hamstring tendon graft at the level of the patella for additional fixation. The technique avoids bone tunnels as well as hardware at the patella. It reduces the risk of intraoperative or postoperative patella fracture or implant-related complications. The stable transosseous fixation technique allows for early rehabilitation.

Research paper thumbnail of Tooth Preparation: A Study on the Effect of Different Variables and a Comparison Between Conventional and Channeled Diamond Burs

Journal of Prosthodontics, 2004

Purpose: The purpose of this study was to evaluate the different variables involved in tooth cutt... more Purpose: The purpose of this study was to evaluate the different variables involved in tooth cutting to characterize intrapulpal temperature generation, cutting efficiency, and bur durability when using conventional and channeled diamond burs.Materials and Methods: Forty premolars and 60 molars were selected for the study. Four diamond burs were paired according to grit size: 125-μm grit: Brasseler Coarse (Control 1) and TDA System (Test 1) burs; and 180-μm grit: Brasseler CRF (Control 2) and NTI Turbo Diamond (Test 2) burs. Each bur was used twice when cutting the premolar teeth, whereas it was used for 60 cuts when cutting the molar teeth. The data were analyzed to compare the correlation of bur design, grit and wear, amount of pressure, advancement rate, revolutions per minute, cutting time and rate, and proximity to the pulp chamber with intrapulpal temperature generation, cutting efficiency, and bur longevity. The mean values of test and control burs in each group were compared using an ANOVA (p < 0.05 for significant differences) for temperature generation and an ANOVA and the Tukey multiple range test (p≤ 0.05) for cutting efficiency and bur longevity.Results: No significant difference was found in intrapulpal temperature generation while cutting premolar and molar teeth with conventional and channeled diamond burs. In both groups, the mean temperature recorded during and after the cutting procedure was lower than the baseline temperature. For premolar teeth, no significant difference was established for control and test burs for the load required to cut into the tooth and the cutting rate. However, both test burs showed significantly fewer revolutions per minute when compared to their control counterparts. For the molar teeth, the Brasseler CRF bur required a significantly lower cutting load when compared to the NTI bur, whereas no difference was noted between the other pair of burs. The cutting rate was significantly higher for both control burs, whereas revolutions per minute (rpm) were greater for control coarser burs only. Overall, channeled burs showed a significantly lower cutting efficiency when compared to conventionally designed burs.Conclusion: Within the limitations of this study, channeled burs showed no significant advantage over conventional diamond burs when evaluating temperature generation and bur durability. Moreover, the cutting efficiency of conventional burs was greater than that of channeled burs.

Research paper thumbnail of Conformational Analysis of 1,2:3,4-Diepoxides:Ab Initio and semiempirical molecular-orbital calculations

Helvetica Chimica Acta, 1992

Using semiempirical and ab initio procedures, the most stable conformations of meso- and rac-biox... more Using semiempirical and ab initio procedures, the most stable conformations of meso- and rac-bioxirane and of some substituted 1,2:3,4-diepoxides were calculated. For threo-diepoxides (having the same relative configurations as rac-bioxirane, 3), two stable conformations with CCCC dihedral angles of ca. 90 and ca. 270° were found. For erythro-diepoxides (derivatives of meso-bioxirane, 4) the calculations suggest three preferred conformations with corresponding dihedral CCCC angles of ca. 90°, ca. 180°, and ca. 270°. The calculations are in fair agreement with the experimental data available for the unsubstituted compounds 3 and 4.

Research paper thumbnail of Einfache methode fur den nachweis von Staphylokokken-Enterotoxin-B in vanillepudding mittels ELISA-test

European Food Research and Technology, 1981

The ELISA for the detection of staphylococcal enterotoxin type B (SEB) was employed to demonstrat... more The ELISA for the detection of staphylococcal enterotoxin type B (SEB) was employed to demonstrate SEB in Dutch Vanilla custard. Due to the sensitivity of the ELISA the extraction procedure, which is necessary when the Ouchterlony test is used, can be abbreviated to a great extent. Two successive extractions at pH 7.4 and pH 4.5 followed by a concentration (1:20) was sufficient to detect 0.1 mcg SEB in 100 g custard. Für den holländischen Vanillepudding (Vla) wurde der ELISA-Test zum Nachweis von Staphylokokken-Enterotoxin-B (SEB) geprüft. Dabei zeigte sich, daß die fur einen serologischen Nachweis (Ouchterlony-Test) notwendige Aufarbeitung weitgehend verkürzt, and damit der erforderliche Arbeitsaufwand entscheidend reduziert werden kann. Die Empfindlichkeit des ELISA-Tests reicht aus, um nach zwei aufeinanderfolgenden Extraktionen bei pH 7,4 und pH 4,5 and anschließender Konzentrierung (1:20) noch 0,1 mcg SEB in 100 g Probe nachzuweisen.

Research paper thumbnail of Phenol as an adjuvant for local control in the treatment ofgiant cell tumour of the bone

Ejso, 1999

Intralesional treatment of giant cell tumour (GCT) of the bone may result in a high rate of local... more Intralesional treatment of giant cell tumour (GCT) of the bone may result in a high rate of local recurrence. The introduction of local adjuvant therapy, such as cementation or phenolization, has lead to a significant reduction in recurrence rates. Due to the combined use of phenol and cementation in most studies, the effect of phenol alone is described in this study. Methods: Twenty primary and nine recurrent surgical procedures in 26 patients with GCT of the bone with a median follow-up of 61 months were reviewed retrospectively. The mean age was 33.5 years (range 13.5-76.5 years). Eighteen curettages and 11 resections were performed. For the curettages, a large bone window was cut followed by high speed burring and bone graft reconstruction. In 11 of 18 curettages and three of 12 resections, phenol was additionally applied. Results: Four patients showed pulmonary metastasis. Three of these four cases also experienced local recurrences. Three patients died due to metastatic disease. In total, five patients developed local recurrence (17.2%); three in the first 2 years and one after 4 years. Four of 18 curettages recurred (22.2%), compared to one of 11 resections (9.1%). Only one of 11 patients (9.1%) treated with curettage and adjuvant phenol recurred, whereas three of seven patients (42.9%) treated with curettage alone recurred. Conclusion: Phenolization is an effective and safe local adjuvant therapy for GCT. We did not observe any significant differences in recurrence rates for curettage, phenolization and bone grafting compared to most published results using cryosurgery or cementation alone. We recommend adjuvant phenolization in the treatment of GCT of the bone after careful curettage in applicable cases, regardless of whether additional cementation is used.

Research paper thumbnail of De Novo Design, Synthesis, and In Vitro Evaluation of a New Class of Nonpeptidic Inhibitors of the Malarial Enzyme Plasmepsin II

Research paper thumbnail of Hamstring graft fixation in MPFL reconstruction at the patella using a transosseous suture technique

Knee Surgery Sports Traumatology Arthroscopy, 2010

Controversy still exists about fixation methods of a hamstring graft to the patella in case of me... more Controversy still exists about fixation methods of a hamstring graft to the patella in case of medial patellofemoral ligament (MPFL) reconstruction. This article presents a surgical technique of hamstring tendon graft fixation to the anatomical MPFL insertion on the patella using transosseous sutures. A superficial bony sulcus is created at the anatomical MPFL insertion site on the medial patellar rim with a bur. A looped hamstring tendon graft is fixed to this superficial sulcus by a pair of nonresorbable transosseous sutures passed across the patella. The retinaculum is sutured on top of the hamstring tendon graft at the level of the patella for additional fixation. The technique avoids bone tunnels as well as hardware at the patella. It reduces the risk of intraoperative or postoperative patella fracture or implant-related complications. The stable transosseous fixation technique allows for early rehabilitation.