Complete denture rehabilitation in the edentulous patient with severe mandibular bone resorption and vascular malformation using closed mouth impression and monoplane occlusion: A case report / 대한치과보철학회지

A patient failed to use conventional complete dentures due to severe mandibular bone resorption and soft tissue hyperplasia on lips, tongue and oral vestibule from vascular malformation. The treatment of choice would be an implant-retained overdenture, however, he refused owing to high cost. The closed mouth impression technique using BPS principle, CR record registration with gothic arch tracing and monoplane occlusion using non-anatomic teeth were used to fabricate complete dentures for this patient. Patient satisfaction, the retention and the stability of complete dentures were highly improved as a result.

Complete denture rehabilitation in the edentulous patient with severe mandibular bone resorption and vascular malformation using closed mouth impression and monoplane occlusion: A case report / 대한치과보철학회지

A patient failed to use conventional complete dentures due to severe mandibular bone resorption and soft tissue hyperplasia on lips, tongue and oral vestibule from vascular malformation. The treatment of choice would be an implant-retained overdenture, however, he refused owing to high cost. The closed mouth impression technique using BPS principle, CR record registration with gothic arch tracing and monoplane occlusion using non-anatomic teeth were used to fabricate complete dentures for this patient. Patient satisfaction, the retention and the stability of complete dentures were highly improved as a result.

Clinical study on screw loosening in dental implant prostheses: a 6-year retrospective study

Objectives@#In this study, we determined the incidence and pattern of screw loosening in patients who received dental implants. @*Materials and Methods@#Patients who received implants between January 2008 and October 2013 and completed their prosthetic rehabilitation were evaluated for the incidence, frequency, and onset of screw loosening using dental charts and radiographs. The association between each factor and screw loosening was analyzed using the chi-square test and a multivariate analysis with binary logistic regression models (P<0.05). @*Results@#Total 1,928 implants were placed in 837 patients (448 males, 389 females), whose follow-up period after loading varied from 0.25 to 70 months (mean period, 31.5 months). Screw loosening occurred in 7.2% of implants. Most cases occurred less than six months after loading. Among those, 22.3% experienced recurrent screw loosening. Screw loosening was most common in the molar region (8.5%) and frequently associated with an implant diameter of ≥5 mm (14.2%). External implant–abutment connections (8.9%) and screw-retained implant prostheses (10.1%) showed higher incidence of problems than internal implant–abutment connections and cement-retained implants, respectively. Screw loosening was most common in implant prostheses with single crowns (14.0%). @*Conclusion@#Within the limits of the current study, we conclude that the incidence of screw loosening differs significantly according to the position of implant placement, the type of implant and manufacturer, implant diameter, the type of implant–abutment connection, the type of retention in the implant prosthesis, and the type of implant prosthesis.

Comparison of marginal and internal discrepancies of zirconia crowns fabricated by various digital scan methods / 대한치과재료학회지

In this study, marginal and internal discrepancies of zirconia crowns fabricated with the CAD/CAM (computer aided design

Comparative evaluation of marginal and internal fit of metal copings fabricated by various CAD/CAM methods / 대한치과보철학회지

PURPOSE: The purpose of the present study was to compare the accuracy of four different metal copings fabricated by CAD/CAM technology and to evaluate clinical effectiveness. MATERIALS AND METHODS: Composite resin tooth of the maxillary central incisor was prepared for a metal ceramic crown and duplicated metal die was fabricated. Then scan the metal die for 12 times to obtain STL files using a confocal microscopy type oral scanner. Metal copings with a thickness of 0.5 mm and a cement space of 50 µm were designed on a CAD program. The Co-Cr metal copings were fabricated by the following four methods: Wax pattern milling & Casting (WM), Resin pattern 3D Printing & casting (RP), Milling & Sintering (MS), Selective laser melting (SLM). Silicone replica technique was used to measure marginal and internal discrepancies. The data was statistically analyzed with One-way analysis of variance and appropriate post hoc test (Scheffe test) (α=.05). RESULTS: Mean marginal discrepancy was significantly smaller in the Group WM (27.66 ± 9.85 µm) and Group MS (28.88 ± 10.13 µm) than in the Group RP (38.09 ± 11.14 µm). Mean cervical discrepancy was significantly smaller in the Group MS than in the Group RP. Mean axial discrepancy was significantly smaller in the Group WM and Group MS then in the Group RP and Group SLM. Mean incisal discrepancies was significantly smaller in the Group RP than in all other groups. CONCLUSION: The marginal and axial discrepancies of the Co-Cr coping fabricated by the Wax pattern milling and Milling/Sintering method were better than those of the other groups. The marginal, cervical and axial fit of Co-Cr copings in all groups are within a clinically acceptable range.

Retrospective study on marginal bone resorption around immediately loaded implants / 대한치과보철학회지

PURPOSE: Patients who treated implant immediate loading within a week after implant placement at Wonkwang University Dental Hospital Implant Center were evaluated marginal bone resorption. These retrospective analyses are intended to reinforce the clinical evidence for the implant immediate loading. MATERIALS AND METHODS: Medical history and radiographic data were investigated, which were the patients' who treated implant immediate loading and restoration with provisional prostheses between January 2005 and June 2016, at Wonkwang University Dental Hospital Implant Center. Total number of implants was 70, marginal bone resorption was measured according to implant length, diameter and connection type. To measure marginal bone resorption, periapical radiographs were taken when the implants were placed and after 6 month. Statistical analysis was done in Mann-whitney U test and Kruskal-wallis test with SPSS 22.0 software (P < .05). RESULTS: Mean marginal bone resorption around immediately loaded implants according to implant connection type was shown 1.24 ± 0.72 mm in internal hexagon connection type and 1.73 ± 1.27 mm in external hexagon connection type. There was no statically significant difference in marginal bone resorption with implant length and diameter. CONCLUSION: Implants with immediated loading in internal hexagon connection type showed less marginal bone resorption significantly than in external hexagon connection type.

Zirconia ceramic fixed dental prosthesis with all-on-4 concept implants for irradiated maxilla: A case report / 대한치과보철학회지

The implant-supported fixed dental prosthesis in irradiated maxilla needs meticulous treatment planning due to low bone healing capacity. All-on-4 concept implantation can reduce the number of implants to be placed avoiding bone grafting procedure. Conventionally, prefabricated angled abutments for tilted implants have been used. However, in this case, it was replaced with computer-aided design and computer-aided manufacturing (CAD/CAM) abutment. This case report described all-on-4 concept implantation and fabrication of CAD/CAM zirconia fixed dental prostheses using CAD/CAM titanium abutments.

Effects of abutment angulation and type of connection on the fracture strength of zirconia abutments / 대한치과보철학회지

PURPOSE: The purpose of this study was to evaluate the fracture strength of straight and angled zirconia abutments for internal hex and external hex implants. MATERIALS AND METHODS: Twenty internal hex implants and 20 external hex implants were prepared. The prefabricated straight zirconia abutments and 17-degree-angled zirconia abutments were connected to those 40 implants. The specimens were classified into 4 groups depending on the connection type and abutment angulation; internal hex implant/straight abutment, group INS; internal hex implant/angled abutment, group INA; external hex implant/straight abutment, group EXS; external hex implant/angled abutment, group EXA. All specimens were loaded at a 30-degree angle with a crosshead speed of 1 mm/min using universal testing machine. The fracture loads were analyzed using 2-way ANOVA and independent t-test (α= .05). RESULTS: The mean fracture load for INS was 955.91 N, 933.65 N for INA, 1267.20 N for EXS, and 1405.93 N for EXA. External hex implant showed a significantly higher fracture load, as compared to internal hex implant (P < .001). No significant differences in fracture loads were observed between the straight and angled abutment in internal hex implants (P = .747) and external hex implants (P = .222). Internal hexes of abutments were fractured horizontally in internal connection implants, while lingual cervical neck portions were fractured in external connection implants. CONCLUSION: The zirconia abutments with external hex implants showed significantly higher fracture strength than those with internal hex implants. However there was no difference in fracture strength between the straight and 17-degree-angled zirconia abutment connected to both implant systems.

Effect of abutment screw length and cyclic loading on removal torque in external and internal hex implants

PURPOSE: The purpose of this study was to evaluate the effects of abutment screw length and cyclic loading on the removal torque (RTV) in external hex (EH) and internal hex (IH) implants. MATERIALS AND METHODS: Forty screw-retained single crowns were connected to external and internal hex implants. The prepared titanium abutment screws were classified into 8 groups based on the number of threads (n = 5 per group): EH 12.5, 6.5, 3.5, 2.5 and IH 6.5, 5, 3.5, 2.5 threads. The abutment screws were tightened with 20 Ncm torque twice with 10-minute intervals. After 5 minutes, the initial RTVs of the abutment screws were measured with a digital torque gauge (MGT12). A customized jig was constructed to apply a load along the implant long axis at the central fossa of the maxillary first molar. The post-loading RTVs were measured after 16,000 cycles of mechanical loading with 50 N at a 1-Hz frequency. Statistical analysis included one-way analysis of variance and paired t-tests. RESULTS: The post-loading RTVs were significantly lower than the initial RTVs in the EH 2.5 thread and IH 2.5 thread groups (P<.05). The initial RTVs exhibited no significant differences among the 8 groups, whereas the post-loading RTVs of the EH 6.5 and EH 3.5 thread groups were higher than those of the IH 3.5 thread group (P<.05). CONCLUSION: Within the limitations of this study, the external hex implants with short screw lengths were more advantageous than internal hex implants with short screw lengths in torque maintenance after cyclic loading.

Comparison of micro CT and cross-section technique for evaluation of marginal and internal fit of lithium disilicate crowns / 대한치과보철학회지

PURPOSE: The purpose of this study was to evaluate the adaptation of lithium disilicate crowns fabricated by CAD-CAM (computer aided design-computer aided manufacturing) and heat-press technique to compare two different measurement methods in assessing fit of the ceramic crowns: micro CT and cross-section technique. MATERIALS AND METHODS: A prepared typodont mandibular molar for ceramic crown was duplicated and ten dies were produced by milling the PMMA (polymethylmethacrylate) resin. Ten vinyl polysiloxane impressions were made and stone casts were produced. Five dies were used for IPS e.max Press crowns with heat-press technique. The other five dies were used for IPS e.max CAD crowns with CAD-CAM technique. Ten lithium disilicate crowns were cemented on the resin dies using zinc phosphate cement with finger pressure. The marginal and internal fits in central buccolingual plane were evaluated using a micro CT. Then the specimens were embedded and cross-sectioned and the marginal and internal fits were measured using scanning electronic microscope. The two measurement methods and two manufacturing methods were compared using Mann-Whitney U test (SPSS 22.0). RESULTS: The marginal and internal fit values using micro CT and cross-section technique were similar, showing no significant differences. There were no significant differences in adaptation between lithium disilicate crowns fabricated with CAD-CAM and heat-press technique. CONCLUSION: Both micro CT and cross-section technique were acceptable methods in the evaluation of marginal and internal fit of lithium disilicate crown. There was no difference in adaptation between lithium disilicate crowns fabricated with CAD-CAM and heat-press technique except occlusal fit.

Comparison of marginal and internal fit of zirconia abutments with titanium abutments in internal hexagonal implants / 대한치과보철학회지

PURPOSE: The aim of this study was to evaluate the fit accuracy of two zirconia and titanium abutments in internal hexagonal implants. MATERIALS AND METHODS: One titanium abutment and two zirconia abutments were tested in internal hexagonal implants (TSV, Zimmer). Prefabricated zirconia abutments (ZirAce, Acucera) and customized zirconia abutments milled by the Zirkonzahn system (Zirkonzahn Max, Zirkonzahn) were selected and prefabricated titanium abutments (Hex-Lock, Zimmer) were used as a control. Eight abutments per group were connected to implants with 30 Ncm torque. The marginal gaps at abutment-implant interface, the internal gaps at internal hex, vertical and horizontal gaps between screws and screw seats in abutments were measured after sectioning the embedded specimens using a scanning electron microscope. Data analysis included one-way analysis of variance and the Scheffe test (n=16, α=0.05). RESULTS: The mean marginal gap of customized zirconia abutment was higher than those of two prefabricated zirconia and titanium abutments. The internal gaps at internal hex showed no significant differences between customized and prefabricated abutments and were higher than those of prefabricated titanium abutments. The mean vertical and horizontal gaps at screw in prefabricated zirconia abutment were higher than those of prefabricated titanium abutment. In the case of customized zirconia abutment, the mean horizontal gap at screw was higher than those of both the prefabricated zirconia and the titanium abutment but the mean vertical gap was not even measureable. The screw seats were clearly formed but did not match with abutment screws in prefabricated zirconia abutments. They were not, however, precisely formed in the case of customized zirconia abutments. CONCLUSION: Within the limitations of this study, the prefabricated titanium abutments showed better fit than the zirconia abutments, regardless of customized or prefabricated. Also, the customized zirconia abutments showed significantly higher marginal gaps and the fit was less accurate between screws and screw seats than the prefabricated abutments, titanium and zirconia.

Full mouth rehabilitation on the patient with class II jaw relation and posterior bite collapse using reestablishment of occlusal vertical dimension: a case report

Loss of molar support and abnormal jaw relationship lead to occlusal disharmony and cause pathologic signs. Full mouth rehabilitations with reestablishment of occlusal schemes are needed. In this case, the 75 year-old female patient showed posterior bite collapse, irregular occlusal plane and Class II jaw relationship. By observing her profile and interocclusal distance, she was diagnosed as loss of occlusal vertical dimension. Treatment plan is to restore maxillay class I removable partial denture and mandibular fixed prosthesis and to establish vertical dimension and harmonious occlusal plane. Occlusal vertical dimension of 19 mm, which is obtained by 7.5 mm increase between maxillary right lateral incisor and mandibular canine, was established using temporary prosthesis via diagnostic wax-up. Patient adaptation with newly formed vertical dimension was verified during 8 week follow-up period. Within the information of interim prostheses, final restoration was constructed and delivered. The patient showed sound occlusal scheme and esthetic profile.

Relationship between Perceived Patient Safety Culture and Patient Safety Management Activities among Health Personnel / 기본간호학회지

PURPOSE: This study was done to explore the relationship between perceived patient safety culture and patient safety management activities among health personnel. METHODS: This study was a cross-sectional survey. Participants were 342 health personnel working in two tertiary hospitals. Self-administered questionnaires were used to collect data from a convenience sample of 254 nurses and 88 doctors. RESULTS: Scores on participants' perceived patient safety culture and patient safety management activities were just over the mean. There were significant differences in patient safety management activities by type of occupation, nurses' position, length of service, and work week. Doctors scored perceived patient safety culture and patient safety management activities significantly lower than nurses. In addition, perceived patient safety culture was significantly related to patient safety management activities. Factors which influence participants' patient safety management activities were communication, type of occupation, overall evaluation of patient safety, supervisor/manager, frequency with which events were reported, and nurse's position. CONCLUSION: Findings provide significant evidence that patient safety management activities are associated with perceived patient safety culture. Therefore, to build a positive safety culture, health personnel, especially doctors and general nurses need to visibly commit to patient safety management activities and be role models to ensure patient safety.

The influence of surface conditioning on the shear bond strength of self-adhesive resin cement to zirconia ceramics / 대한치과보철학회지

PURPOSE: To evaluate the effect of surface conditioning on the shear bond strength of zirconium-oxide ceramic to 4 luting agents. MATERIAL AND METHODS: A total of 120 disk-shaped zirconium-oxide ceramic blocks (3Y-TZP, Kyoritsu, Japan) were treated as follows: (1) Sandblasting with 110 microm aluminum-oxide (Al2O3) particles; (2) tribochemical silica coating (Rocatec) using 110 microm Al2O3 particles modified by silica; (3) no treatment. Then zirconium-oxide ceramic blocks bonded with 4 luting cements (RelyX luting (3M ESPE), Maxcem (Kerr), Nexus3 (Kerr), Rely X Unicem (3M ESPE)). Each group was tested in shear bond strengths by UTM. A 1-way analysis of variance and 2-way analysis of variance was used to analyze the data (alpha = .05). RESULTS: RelyX unicem in combination tribochemical silica-coating produced a highest bond strength (P < .05). Air abrasion group and Rocatec treatment groups resulted in significantly higher than no conditioning group (P < .05). RelyX Luting groups showed lower bond strength than other groups. There were significant differences among groups (P < .05). CONCLUSION: Within the limitation of this study, RelyX Unicem cement provided the highest bond strength and Rocatec treatment enhanced the bond strength.

Aneurysm of the Proximal Subclavian Artery: A case report / 대한흉부외과학회지

Subclavian artery aneurysms are quite rare and they are known to be as only 1% of all peripheral aneurysms. Atherosclerotic disease is the most common cause of subclavian artery aneurysms. These aneurysms can cause rupture, thrombosis, embolisms or symptoms by local compression. Surgical operations are generally performed as treatment. We report here on a case of successful surgical treatment for a right proximal subcalvian artery aneurysm, and the surgery was performed via the medical exclusion method.

Effects of laser-irradiated dentin on shear bond strength of composite resin / 대한치과보철학회지

PURPOSE: This study was conducted to evaluate the shear bond strength of composite resin to dentin when etched with laser instead of phosphoric acid. MATERIAL AND METHODS: Recently extracted forty molars, completely free of dental caries, were embedded into acrylic resin. After exposing dentin with diamond saw, teeth surface were polished with a series of SiC paper. The teeth were divided into four groups composed of 10 specimens each; 1) no surface treated group as a control 2) acid-etched with 35 percent-phosphoric acid 3) Er:YAG laser treated 4) Er,Cr:YSGG laser treated. A dentin bonding agent (Adapter Single Bond2, 3M/ESPE) was applied to the specimens and then transparent plastic tubes (3 mm of height and diameter) were placed on each dentin. The composite resin was inserted into the tubes and cured. All the specimens were stored in distilled water at 37degree C for 24 hours and the shear bond strength was measured using a universal testing machine (Z020, Zwick, Germany). The data of tensile bond strength were statistically analyzed by one-way ANOVA and Duncan's test at alpha = 0.05. RESULTS: The bond strengths of Er:YAG laser-treated group was 3.98 +/- 0.88 MPa and Er,Cr:YSGG laser-treated group showed 3.70 +/- 1.55 MPa. There were no significant differences between two laser groups. The control group showed the lowest bond strength, 1.52 +/- 0.42 MPa and the highest shear bond strength was presented in acid-etched group, 7.10 +/- 1.86 MPa (P < .05). CONCLUSION: Laser- etched group exhibited significantly higer bond strength than that of control group, while still weaker than that of the phosphoric acid-etched group.

The study of shear bond strength of a self-adhesive resin luting cement to dentin / 대한치과보철학회지

PURPOSE: The objective of this study was to compare the bonding characteristics of a new self-adhesive resin cement to dentin, which does not require bonding and conditioning procedure of the tooth surface, and conventional resin cement. The effect of phosphoric acid etching prior to application of self-adhesive resin cement on the shear bond strength was also evaluated. MATERIAL AND METHODS: Fortyfive non-carious human adult molars extracted within 6 months were embedded in chemically cured acrylic resin. The teeth were ground with a series of SiC-papers ending with 800 grit until the flat dentin surfaces of the teeth were exposed. The teeth were randomly divided into 3 experimental groups. In group 1, self-adhesive resin cement, RelyX Unicem (3M ESPE, Seefeld, Germany) was bonded without any conditioning of teeth. In group 2, RelyX Unicem was bonded to teeth after phosphoric acid etching. For group 3, Syntac Primer (Ivoclar Vivadent AG, Schaan, Liechtenstein) was applied to the teeth before Syntac adhesive (Ivoclar Vivadent AG, Schaan, Liechtenstein) and Helibond (Ivoclar Vivadent AG, Schaan, Liechtenstein) followed by conventional resin cement, Variolink II (Ivoclar Vivadent AG, Schaan, Liechtenstein). To make a shear bond strength test model, a plastic tuble (3 mm diameter, 3 mm height) was applied to the dentin surfaces at a right angle and filled it with respective resin cement, and light-polymerized for 40 seconds. All the specimens were stored in distilled water at 37 degree C for 24 hours before test. Universal Testing Machine (Z020, Zwick, Ulm, Germany) at a cross head speed of 1 mm/min was used to evaluate the shear bond strength. The failure sites were inspected under a magnifier and Scanning Electron Microscope. The data was analyzed with One way ANOVA and Scheffe test at alpha = 0.05. RESULTS: (1) The shear bond strengths to dentin of RelyX Unicem was not significantly different from those of Variolink II/Syntac. (2) Phosphoric acid etching lowered the shear bond strength of RelyX Unicem significantly. (3) Most of RelyX Unicem and Variolink II showed mixed fractures, while all the specimens of RelyX Unicem with phosphoric acid etching demonstrated adhesive failure between dentin and resin cement. CONCLUSION: Shear bond strength to dentin of self-adhesive resin cement is not significantly different from conventional resin cement, and phosphoric acid etching decrease the shear bond strength to dentin of self-adhesive resin cement.

Long-term Outcome of Trigeminal Nerve Block with Alcohol for the Treatment of Trigeminal Neuralgia / 대한통증학회지

BACKGROUND: Recently trigeminal nerve block with alcohol (TnbA) for the treatment of trigeminal neuralgia (TN) has come to be known as a procedure with a short-term effect and high complications. There has been none of report about long-term outcome of TnbA for TN. The objective of this prospective study for the long-term results of TnbA was to analyse the pain free duration and complication after the administration of blocks and compare them in the first block and subsequent blocks. METHODS: From March 1996 to May 2005, 304 consecutive patients with primary trigeminal neuralgia were treated with TnbA including supraorbital nerve block, infraorbital nerve block, maxillary nerve (V2) block, mandibular nerve (V3) block, and V2 and V3 at the same time and were prospectively followed up every two months for 10 years. RESULTS: The mean value of pain free duation of 1st, 2nd and 3rd TnbA were 43, 38 and 48 months, respectively using Kaplan-Meier analysis. The probability of pain recurrence in 1 and 3 years after the 1st, 2nd and 3rd blocks were 25%, 25%, 20% and 53%, 54%, 34%, respectively. The pain free durations of first and subsequent blocks were not statistically different. Complications were reported at 36 (11.8%), 5 (4.2%), and 0 in 1st, 2nd and 3rd blocks. CONCLUSIONS: TnbA showed the relatively long duration of pain free and low incidence of complications. Repeated TnbA has pain free duration as long as the 1st block and less complications as well. TnbA is a valuable treatment of TN as a percutaneous procedure.

The fitness of adjustable dental impression trays on the Koreans / 대한치과보철학회지

Purpose: this study was to evaluate the fitness of adjustable dental impression trays on the Koreans : the trays used in the previous study by Kim et al. as part of the dental adjustable tray development project were improved and modified. Material and method: The patterns of tray were made through CAD-CAM process, and a simple silicone-base molds were made from them. The trial products were reproduced by pouring polyurethane into these molds. 30 male students(Wonkwang University, Dental College) and 30 female students (Wonkwang Health Science College, Department of Dental Hygiene) were selected and Reversible hydrocolloid impression materials were used for this study. The fitness of the trays was evaluated by measuring the width and length of impression materials of each measurement sites. Results and conclusion: 1. In adapting the trays inside the mouth, a uniform width of impression material(3.6mm) was obtained in most sites due to the tooth stops and the inclined planes accommodating the width of the tray. 2. The thickness of impression material in the central part of the palate was a mean 9.8 mm, which turned out to be somewhat thick. 3. In the mandible, the thickness of the impression material in the lingual side inferior to the contact point of the 1st and 2nd molars was 2.7mm, and the thickness of the material in the lingual side of the rearmost margin was 2.5 mm. The thickness of the impression material of these areas was relatively thin.

The Effects of Intrathecal Midazolam Added to Bupivacaine Spinal Anesthesia / 대한마취과학회지

BACKGROUND: Intrathecal additives are often used to enhance spinal anesthesia. Midazolam has been reported to have a spinally mediated antinociceptive effect. The aim of this study was to evaluate the effect of midazolam in addition to hyperbaric bupivacaine in spinal anesthesia. METHODS: Sixty ASA 1 or 2 adult patients scheduled for lower extremity surgery under spinal anesthesia were studied. Patients were allocated randomly to one of four groups to receive 2.8 ml of one of either of the following intrathecal solutions: hyperbaric bupivacaine 12 mg and normal saline 0.4 ml (group 1; n = 15), hyperbaric bupivacaine 12 mg, midazolam 0.5 mg and normal saline 0.3 ml (group 2; n = 15), hyperbaric bupivacaine 12 mg, midazolam 1 mg, and normal saline 0.2 ml (group 3; n = 15), or hyperbaric bupivacaine 12 mg and midazolam 2 mg (group 4; n = 15). The level, onset, and duration of spinal anesthesia as well as hemodynamic changes and side effects were assessed. RESULTS: The duration of spinal anesthesia was increased in the midazolam addition groups. The duration of anesthesia was significantly increased in group 4 compared to the other 3 groups (P<0.05). The onset, blood pressure, heart rate, and levels of sedation were no different between the 4 groups. No neurological deficit or other significant adverse effects were recorded. CONCLUSIONS: The addition of intrathecal midazolam to hyperbaric bupivacaine significantly improve the duration of spinal anesthesia without significant adverse effects. Therefore, the use of intrathecal midazolam in a dose not exceeding 2 mg can be used as an effective additive for spinal anesthesia.