Failure torque of ceramic neck titanium implant.

STATEMENT OF PROBLEM: Dental implants are typically made of titanium. However, with the current systems on the market, the implant neck often shows through the gingival tissues as a black or dark gray line and/or as a grayish discoloration of the peri-implant soft tissue. PURPOSE: The purpose of this in vitro study was to test a new implant design. The key component of this design is the ceramic shell that covers the polished collar of the tissue-level titanium implant and masks its dark color to mimic natural dentition. The main purpose was to determine the maximum torque for fracturing the ceramic shell and compare it with clinical implant insertion torque value. MATERIAL AND METHODS: Type 4 commercially pure titanium endosseous implants of 3 different diameters (3.3, 4.1, and 4.8 mm) were used. Porcelain was applied in 0.5-mm thickness to the polished collar of each implant. An axial-torsional universal testing machine was used to twist the implants until failure. The data (n=10) were statistically analyzed by ANOVA and the Tukey honest significant difference test (α=.05). The maximum torque for each diameter group was also compared with the optimum clinical implant insertion torque value of 35 Ncm (control) using a 1-sample t test. RESULTS: None of the tested groups had a fractured ceramic shell. Instead, the implant carriers fractured at the maximum torque levels. Therefore, the fracture of the implant carriers was selected as the maximum (failure) torque value. A statistical difference was found for the failure torque between the 3.3-mm diameter and the other 2 diameters (P<.001) although no statistical differences were found between the 4.1-mm and 4.8-mm diameters (P=.106). A statistically significant difference was found between the failure torque of any one of the tested groups and the clinical insertion torque (P<.001). CONCLUSIONS: The ceramic shells did not fracture. Instead, the implant carriers fractured at certain torque levels. These levels were sufficiently higher than the clinical torque values.

Color masking measurement for ceramic coating of titanium used for dental implants.

STATEMENT OF PROBLEM: Poor implant placement or thin gingival tissue and progressive bone resorption may lead to the dark metal color showing through the peri-implant soft tissue. Whether the dark color can be adequately masked is unclear. PURPOSE: The purpose of this in vitro study was to test the color masking effect of porcelain applied on titanium used in fabricating the polished collar of tissue level implants. MATERIAL AND METHODS: Type 4 commercially pure titanium disks and 5 porcelain dentin shades (A2, A3, B2, C2, and D3) were used. Ten titanium disk specimens per porcelain shade were airborne-particle abraded and ultrasonically cleaned. Porcelain was condensed directly on the specimens, fired, and finished (1200 grit SiC paper). The color (L*a*b* values) of the polished specimens was measured with a reflective spectrophotometer. The specimens were then ground and polished in 0.1 mm increments. Color was measured and ΔE values were calculated at each increment until the thickness at which the ΔE was greater than 3.3 was identified. The data (n=10) were statistically analyzed by ANOVA and the Tukey multiple-comparison test (α=.05). RESULTS: For ceramic thicknesses greater or equal to 0.5 mm for the A2, A3, B2, and C2 shades, the ΔE was less than 3.3. This value was 0.4 mm for the D3 shade. CONCLUSIONS: The minimum ceramic thickness required to mask the underlying titanium color is 0.5 mm for all shades except D3, which only needs 0.4 mm. L* decreased with thickness increase. Redness and yellowness increased with thickness increase.

A new premixed self-etch adhesive for bonding orthodontic brackets.

OBJECTIVE: To determine if a new premixed self-etch adhesive can be used to successfully bond orthodontic brackets to enamel. MATERIALS AND METHODS: Forty human molars were cleaned, mounted, and randomly divided into two groups. In group 1, 20 teeth were conditioned using the self-etching primer Transbond Plus (3M Unitek, Monrovia, Calif). In group 2, 20 teeth were conditioned using a new premixed self-etching adhesive, AdheSE One (Ivoclar Vivadent Inc, Amherst, NY). Both groups were bonded using brackets precoated with a composite adhesive. The teeth were debonded within half an hour following initial bonding using a universal testing machine. After debonding, the enamel surface was examined under 10x magnifications to determine the amount of residual adhesive remaining on the tooth. A Student's t-test was used to compare the shear bond strength (SBS) of the two groups, and the Chi-square test was used to compare the adhesive remnant index (ARI) scores for the two adhesive systems. RESULTS: The mean SBS of the brackets bonded to the teeth using AdhesSE One was 3.6 +/- 1.3 MPa and was significantly lower (t = 2.80, P = .01) than the SBS of the brackets bonded using Transbond Plus (x = 5.9 +/- 3.2 MPa). The comparisons of the ARI scores between the two groups (chi2 = 19.26) indicated that bracket failure mode was also significantly different (P < .001), with more adhesive remaining on the teeth bonded using Transbond Plus. CONCLUSIONS: The SBS of the new premixed self-etching adhesive needs to be increased for it to be successfully used for bonding orthodontic brackets.

Evaluation of a new nano-filled restorative material for bonding orthodontic brackets.

AIM: To compare the shear bond strength of a nano-hybrid restorative material, Grandio (Voco, Cuxhaven, Germany), to that of a traditional adhesive material (Transbond XT; 3M Unitek, Monrovia, CA, USA) when bonding orthodontic brackets. MATERIAL AND METHODS: Forty teeth were randomly divided into 2 groups: 20 teeth were bonded with the Transbond adhesive system and the other 20 teeth with the Grandio restorative system, following manufacturer's instructions. Student t test was used to compare the shear bond strength of the 2 systems. Significance was predetermined at P 5 .05. RESULTS: The t test comparisons (t = 0.55) of the shear bond strength between the 2 adhesives indicated the absence of a significant (P = .585) difference. The mean shear bond strength for Grandio was 4.1 +/- 2.6 MPa and that for Transbond XT was 4.6 +/- 3.2 MPa. During debonding, 3 of 20 brackets (15%) bonded with Grandio failed without registering any force on the Zwick recording. None of the brackets bonded with Transbond XT had a similar failure mode. CONCLUSIONS: The newly introduced nano-filled composite materials can potentially be used to bond orthodontic brackets to teeth if its consistency can be more flowable to readily adhere to the bracket base.

Early shear bond strength of a one-step self-adhesive on orthodontic brackets.

OBJECTIVE: The purpose of this study was to determine whether a self-adhesive universal cement, RelyX Unicem (3M ESPE, Seefeld, Germany), can be used successfully to bond orthodontic brackets to enamel. MATERIALS AND METHODS: Forty human molars were cleaned, mounted, and randomly divided into two groups: 20 orthodontic brackets were bonded to teeth using RelyX Unicem, and 20 brackets were bonded using the Transbond XT (3M Unitex, Monrovia, Calif) adhesive system. The teeth were debonded within 30 minutes after initial bonding using a universal testing machine. After debonding, the enamel surface was examined under 10x magnification to determine the amount of residual adhesive remaining on the tooth. Student's t-test was used to compare the shear bond strength (SBS) of the two groups, and the chi-square test was used to compare the Adhesive Remnant Index (ARI) scores for the two adhesive systems. RESULTS: The mean SBS of the brackets bonded using the RelyX Unicem was 3.7 +/- 2.1 MPa and was significantly lower (t = 2.07, P = .048) than the SBS of the brackets bonded with the Transbond system (x = 5.97 +/- 4.2 MPa). The comparisons of the ARI scores between the two groups (chi(2) = 17.4) indicated that bracket failure mode was significantly different (P = .002) with more adhesive remaining on the teeth bonded with Transbond XT. CONCLUSIONS: The SBS of the self-adhesive universal cement needs to be increased for it to be successfully used for bonding orthodontic brackets.

Core buildup repair using a clear matrix: a case report and clinical technique.

The fracture of core buildup material is common in dental practice. This article describes a core buildup repair technique utilizing a custom matrix. This technique enables the dentist to reestablish the original contour and alignment of the broken core buildup and assures excellent crown fit in a short amount of time with a predictably successful outcome.

Comparison of shear bond strength of two self-etch primer/adhesive systems.

Orthodontic brackets adhesive systems use three different agents, an enamel conditioner, a primer solution, and an adhesive resin. A unique characteristic of some new bonding systems is that they combine the conditioning, priming, and adhesive agents into a single application. The purpose of this study was to assess and compare the effects of using one-step and two-step self-etch primer/adhesive systems on the shear bond strength of orthodontic brackets. The brackets were bonded to extracted human molars according to one of two protocols. Group I (control): a two-step self-etch acidic primer/adhesive system was used, Transbond Plus was applied to the enamel surface as suggested by the manufacturer. The brackets were bonded with Transbond XT and light cured for 20 seconds. Group II: a one-step self-etch, self-adhesive resin cement system, Maxcem, was applied directly to the bracket. The self-etch primer/adhesive is made of two components that mix automatically during application. The brackets were then light cured for 20 seconds. The mean shear bond strength of the two-step acid-etch primer/adhesive was 5.9 +/- 2.7 Mpa and the mean for the one-step system was 3.1 +/- 1.7 MPa. The in vitro findings of this study indicated that the shear bond strengths (t = 3.79) of the two adhesive systems were significantly different (P = .001). One-step adhesive systems could potentially be advantageous for orthodontic purposes if their bond strength can be improved.

The effect of tooth bleaching on the shear bond strength of orthodontic brackets.

INTRODUCTION: The purpose of this study was to determine the effect of enamel bleaching on the shear bond strength of orthodontic brackets bonded with a composite adhesive. METHODS: Two protocols were used on 60 human molars. In the at-home bleaching group (n = 30), Opalescence bleaching agent (Ultradent, South Jordan, Utah), which contains 10% carbamide peroxide, was brushed onto the teeth daily for 14 days and left for 6 hours each day. Teeth in the in-office group (n = 30) were treated with Zoom! (Discus Dental, Culver City, Calif), which contains 25% hydrogen peroxide gel, and then exposed to a light source for 20 minutes; these teeth were treated twice. After bleaching, the specimens were randomly divided into equal subgroups and stored in artificial saliva at 37 degrees C for 7 or 14 days before bonding. Shear bond strength testing was performed on all teeth. The Kruskal-Wallis test for nonparametric means was used to determine whether significant differences existed between the various subgroups and an unbleached control group. RESULTS: The mean shear bond strength for the control group was 5.6 +/- 1.8 MPa. Means for the at-home groups were 5.2 +/- 3.6 MPa and 7.2 +/- 3.2 MPa for the 7- and 14-day waiting periods, respectively. Means for the in-office groups were 5.1 +/- 5.3 MPa and 6.6 +/- 2.6 MPa for the 7- and 14-day waiting periods, respectively. The Kruskal-Wallis test (X(2) = 8.089) indicated no significant differences between the 5 subgroups (P = .088). CONCLUSIONS: The results showed that in-office and at-home bleaching did not affect the shear bond strength of orthodontic brackets to enamel.

The effect of porcelain surface conditioning on bonding orthodontic brackets.

The purpose of this study was to evaluate the effects of a new self-etching primer/ adhesive used to enhance the shear strength of orthodontic brackets bonded to porcelain surfaces. Forty-five porcelain maxillary central incisor teeth were used in the study. The teeth were divided randomly into three groups: group I (control), the porcelain teeth were etched with 37% phosphoric acid followed by a sealant and the brackets were bonded with a composite adhesive; group II, the porcelain teeth were microetched and hydrofluoric acid and silane applied and metal brackets were then bonded with the composite adhesive; and group III, the porcelain teeth were etched with phosphoric acid and a self-etching primer/adhesive applied before bonding. Brackets precoated with the adhesive were used on all three groups of teeth. All teeth were stored for 24 hours at 37 degrees C before debonding. The results of the analysis of variance (F = 10.7) indicated that there was a significant difference (P = .001) between the three groups. The mean shear bond strengths of conventional bonding using a 37% phosphoric acid and sealant was 4.4 +/- 2.7 MPa, whereas that of microetching followed by the application of hydrofluoric acid and silane was 11.2 +/- 4.7 MPa, and for the new self-etching primer/adhesive it was 10.3 +/- 5.3 MPa. The last two groups had the highest bond strength values and were not significantly different from each other.

Conservative inlay fixed partial denture: a clinical and laboratory technique.

Fiber-reinforced composite (FRC) fixed partial dentures (FPDs) offer a clinical alternative for the restoration of single missing teeth and short-span posterior and anterior FPDs. This treatment modality is conservative and cost-efficient. The continuous improvement of adhesives and resin-based composite systems makes this type of restoration successful with good esthetic and functional results. This article reports the case of a patient who received an FRC FPD as a treatment modality and illustrates the clinical procedure as well as a new laboratory technique utilizing a clear matrix for the fabrication of the prosthesis.

Comparison of bonding time and shear bond strength between a conventional and a new integrated bonding system.

Conventional adhesive systems use 3 different agents, an enamel conditioner, a primer solution, and an adhesive resin during the bonding of orthodontic brackets to enamel. A characteristic of some new bonding systems is that they combine the conditioning and priming agents into a single application as well as precoat the bracket with the adhesive in an attempt to save time during the bonding procedure. This study compared the total bonding time and shear bond strength (SBS) of 2 bracket-bonding systems: (1) an integrated system that incorporates a self-etching primer and precoated brackets and (2) a conventional system in which the etchant and primer are applied separately and the adhesive applied to the bracket by the clinician. The results of the SBS and the total bonding time comparisons (t = 3.451) of the 2 adhesive systems showed a significant difference (P = .0001). The mean SBS was 9.4+/-3.7 MPa for the new bonding system and 6.2+/-4.4 MPa for the conventional system. The mean total bonding time was 36.5 s/tooth for the new system and 46.7 s/tooth for the conventional system. The clinician has to decide whether the increase in bond strength, the decrease in the total bonding time, and the steps saved during the bonding procedure with the new bonding system balance the increased cost incurred.

Bonding orthodontic brackets to porcelain using different adhesives/enamel conditioners: a comparative study.

AIM: To evaluate the use of new adhesive/primer materials, including an experimental self-etch primer and a cyanocrylate adhesive, to enhance the shear strength of orthodontic brackets bonded to porcelain surfaces. MATERIAL AND METHODS: Sixty porcelain maxillary central incisor teeth were used. The teeth were randomly divided into four groups: group 1, teeth were etched with 37% phosphoric acid and the brackets were bonded with a composite adhesive; group 2, teeth were microetched, hydrofluoric acid and silane applied, and then the brackets were bonded with a composite adhesive; group 3, an acid-etch primer was used, then the brackets were bonded with the same composite adhesive as in the first 2 groups; group 4, teeth were etched with 35% phosphoric acid and the brackets were bonded with the cyanoacrylate adhesive. RESULTS: The analysis of variance comparing the groups tested (F = 9.446) indicated that there was a significant difference between the 4 groups. The cyanoacrylate adhesive had the lowest shear bond strength (mean = 1.7 +/- 2.1 MPa), followed by the conventional bonding using a 37% phosphoric acid etch and composite (mean = 2.1 +/- 1.2 MPa). The use of Transbond after microetching, with the application of hydrofluoric acid and silane, provided the highest shear bond strength (mean = 5.5 +/- 2.7 MPa). Transbond used with the acid etch-primer had a lower bond strength (mean = 3.8 +/- 2.5 MPa), but was not significantly different from the microetch/hydrofluoric acid/silane group. CONCLUSION: The results indicated that the use of a phosphoric acid etch with either a cyanoacrylate or composite adhesive to bond orthodontic brackets to porcelain surfaces produced significantly lower shear bond strength. Self-etch primers produced higher but less consistent shear bond strength for bonding orthodontic brackets. The most reliable bonding procedure to porcelain surfaces is through microetching with the use of hydrofluoric acid and a silane coupler before bonding, but this also produces the greatest damage to the porcelain surface.

The use of Ormocer as an alternative material for bonding orthodontic brackets.

As new adhesives, composite resins, and bonding techniques were introduced, orthodontists adopted some of these innovations and added them to their armamentarium. The purpose of this study was to compare the shear bond strength (SBS) of two adhesive materials; one with an organically modified ceramic matrix, Admira (Voco, Cuxhaven, Germany) and another that contains the traditional Bis GMA matrix namely Transbond XT (3M Unitek, Monrovia, Calif). The new materials have a lower wear rate and are more biocompatible than traditional composites. Forty molar teeth were randomly divided into two groups: 20 teeth bonded with the Transbond adhesive system and the other 20 teeth with the Admira bonding system. Student's t-test was used to compare the SBS of the two adhesives. Significance was predetermined at P < or = .05. The results of the t-test comparisons (t = 0.489) of the SBS indicated that there was no significant (P = .628) difference between the two adhesives tested. The mean SBS for Admira was 5.1 +/- 3.3 MPa and that for Transbond XT was 4.6 +/- 3.2 MPa. It was concluded that the new material, Ormocer, which is an organically modified ceramic restorative material can potentially have orthodontic applications if available in a more flowable paste. These new materials are more biocompatible and have lower wear rate including bonding orthodontic brackets to teeth.

Waterline disinfectant effect on the shear bond strength of orthodontic brackets.

The purpose of this study was to determine whether the use of an iodine compound for disinfecting the waterlines in dental units has an effect on the shear bond strength of orthodontic brackets bonded to enamel. Forty molar teeth were divided randomly into two groups- group 1 control: twenty teeth were etched for 15 seconds with 35% phosphoric acid, washed with a distilled water spray for 10 seconds, stored in distilled water for 5 minutes, dried to a chalky white appearance, and the sealant applied to the etched surface; group 2 experimental: twenty teeth were etched for 15 seconds with 35% phosphoric acid and washed for 10 seconds with water containing iodine. The teeth were stored for five minutes in the iodinated water, dried to a chalky white appearance, and the sealant applied to the etched surface as in the control group. Precoated brackets were placed on all the teeth and light cured for 20 seconds. All teeth were debonded within 30 minutes from the initial time of bonding. The t-test results (t = 1.74) indicated that there were no significant (P = .09) differences in the shear bond strengths of the teeth that were washed and immersed in the iodine solution and the control group in which distilled water was used. The mean shear bond strengths for the two groups were 6.5 +/- 3.5 MPa and 4.7 +/- 3.1 MPa, respectively.

Effect of water storage on the shear bond strength of a cyanoacrylate adhesive: clinical implications.

AIM: To compare the effects of water storage on the shear bond strength of a cyanoacrylate adhesive system at three time intervals: (1) within 30 minutes after bonding the bracket to the tooth; (2) 24 hours from the time of bonding; and (3) after 30 days of storage in water at 37 degrees C. METHODS: Sixty freshly extracted human molars were collected and stored in a solution of 0.1% (weight/volume) thymol. The teeth were cleansed and polished, then randomly separated into three groups: group 1, cyanoacrylate adhesive debonded within 30 minutes from initial bonding; group 2, cyanoacrylate adhesive debonded after 24 hours immersion in deionized water at 37 degrees C; group 3, cyanoacrylate adhesive debonded after 30 days immersion in deionized water at 37 degrees C. RESULTS: Analysis of variance (F = 11.94) comparing the experimental groups indicated the presence of significant differences between the three groups (P = .0001). The shear bond strengths were significantly greater in the two groups debonded after 30 minutes (mean = 5.8+/-2.4 MPa) and 24 hours (mean = 7.1+/-3.3 MPa) than the group debonded after 30 days of water storage (mean = 2.7+/-2.0 MPa). CONCLUSION: The present findings indicate that the cyanoacrylate adhesive has clinically adequate shear bond strengths at 30 minutes and 24 hours after initial bonding, but that the bond strength decreases by 50% within 30 days. The clinician needs to carefully take the overall properties of the adhesive into consideration.

The effect of variation in mesh-base design on the shear bond strength of orthodontic brackets.

This study compared the shear bond strengths of two metallic orthodontic brackets, one with a single-mesh bracket base and the other with a double-mesh bracket base. The Transbond XT adhesive system was used to bond all brackets to the teeth. Two types of brackets were compared, ie, 20 Ovation metal bracket series, with a double-mesh base (Super-mesh) and an 81.50 gauge (0.126 inch), and 20 Victory series metal brackets that have a miniature single-mesh base. The teeth were bonded and debonded within half an hour from the initial bonding. The enamel surface was examined under 10x magnification to determine how much residual adhesive remained on the tooth. Student's t-test was used to compare the shear bond strength of the two groups. Chi-square test was used to compare the adhesive remnant index (ARI) scores for the two bracket types. The mean shear bond strength for the double-mesh brackets was 5.2 +/- 3.9 MPa and for the single-mesh brackets was 5.8 +/- 2.8 MPa. The t-test comparisons indicated that they were not significantly different from each other (P = .157). The ARI comparisons indicated that both bracket types had similar bracket failure modes and were not significantly different from each other (chi2 = 2.0, P = .5). These results indicated that single- and double-mesh bracket bases have comparable shear bond strength and bracket failure modes.

Evaluation of modifying the bonding protocol of a new acid-etch primer on the shear bond strength of orthodontic brackets.

The purpose of the study was to evaluate the shear bond strength of orthodontic brackets when light curing both the self-etch primer and the adhesive in one step. Fourty eight teeth were bonded with self-etch primer Angel I (3M/ESPE, St Paul, Minn) and divided into three groups. In group I (control), 16 teeth were stored in deionized water for 24 hours before debonding. In group II, 16 teeth were debonded within half-an-hour to simulate when the initial archwires were ligated. In group III, 16 additional teeth were bonded using exactly the same procedure as in groups I and II, but the light cure used for 10 seconds after applying the acid-etch primer was eliminated, and the light cure used for 20 seconds after the precoated bracket was placed over the tooth. This saved at least two minutes of the total time of the bonding procedure. The teeth in this group were also debonded within half-an-hour from the time of initial bonding. The teeth debonded after 24 hours of water storage at 37 degrees C had a mean shear bond strength of 6.0 +/- 3.5 MPa, the group that was debonded within half-an-hour of two light exposures had a mean shear bond strength of 5.9 +/- 2.7 MPa, and the mean for the group with only one light cure exposure was 4.3 +/- 2.6 MPa. Light curing the acid-etch primer together with the adhesive after placing the orthodontic bracket did not significantly diminish the shear bond strength as compared with light curing the acid-etch primer and the adhesive separately.

Comparison of the shear bond strength of 2 self-etch primer/adhesive systems.

Conventional adhesive systems use 3 different agents-an enamel conditioner, a primer solution, and an adhesive resin for bonding orthodontic brackets to enamel. A unique characteristic of some new bonding systems in operative dentistry is that they combine the conditioning and priming agents into a single application. Combining conditioning and priming saves time and should be more cost-effective to the clinician and indirectly to the patient. The purpose of this study was to assess and compare the effects of mix and no-mix self-etch primers/bonding systems on the shear bond strengths of orthodontic brackets. The brackets were bonded to extracted human molars according to the following protocols. In group I, a self-etch acidic primer/adhesive system, Transbond Plus (3M Unitek, Monrovia, Calif), was applied on the enamel surface as suggested by the manufacturer; it has 2 components that must be mixed before use. The brackets were then bonded with Transbond XT and light-cured for 20 seconds. In group II, a no-mix self-etch bracket adhesive system, Ideal 1 (GAG International, Islandia, NY), was applied to the teeth as suggested by the manufacturer. The self-etch primer has 1 component that does not need to be mixed before use. The brackets were then bonded with the adhesive and light-cured for 20 seconds. The in vitro findings indicated that the shear bond strength comparisons (t = 0.681) of the 2 adhesive systems were not significantly different (P =.501). The mean shear bond strength of the 2-component acid etch primer was 5.9 +/- 2.7 MPa, and the mean for the 1-component system was 6.6 +/- 3.2 MPa. The clinician should consider the bond strength and the ease of application of the various components of the bracket bonding systems available on the market.

Evaluation of a new curing light on the shear bond strength of orthodontic brackets.

With the introduction of photosensitive (light-cured) restorative materials in dentistry, various methods were suggested to enhance their polymerization and to shorten the curing time including layering and the use of more powerful light-curing devices. The purpose of this study was to determine the effect of using a new light-curing apparatus that uses a light-emitting diode (LED) on the shear bond strength of an orthodontic adhesive. The new light-curing apparatus used in the study was UltraLume 2 (Ultradent USA, South Jordan, Utah) that has an 8-mm footprint and can simultaneously cure two orthodontic brackets. Forty teeth were etched with 37% phosphoric acid, washed and dried, and sealant applied, and then precoated brackets with the Transbond adhesive (APC II, 3M Unitek, Monrovia, Calif) were placed. The teeth were randomly divided into two groups according to the curing light used. In group I (control), 20 brackets were cured using an Ortholux (3M Unitek) halogen curing light for 20 seconds. In group II, 20 brackets were cured using the new LED light for 20 seconds. The findings indicated no significant (P = .343) differences in the shear bond strength between the Ortholux halogen light (5.1 +/- 2.5 MPa) and the UltraLume 2 LED light when the two groups were compared using Student's t-test (t = -0.961). In conclusion, the advantages of the new unit include the ability to cure two brackets at a time and a smaller light-emitting apparatus for the clinician to handle.