Lojic+ – a 60% silver non gamma 2 platinum spherical alloy
- Smales R. J., Gerke D. C., Clinical Behavior over Three Years of GS-80 and Lojic+ Amalgam Alloys, Aust. Dent. J. 1994;39(6):344-347.
- Lojic Plus, The Dental Advisor, Volume 4, No. 5 September/October 1994.
- Smales R J, Rupinskas L., Valiant-PhD and Lojic N amalgam alloys: four-year clinical results. Australian Dental Journal 1991;36(4):293-7.
- Brown I. H., Miller D. R., Alloy Particle Shape and Sensitivity of High Copper Amalgams to Manipulative Variables. American Journal of Dentistry. 1993;6:248-254.
- Roberts H. W. Lt Col, Coover M Lt Co, Meyer R, Mitchell W, Beasley B, Berridge J., Evaluation of Lojic+ Amalgam. USAF Dental Investigation Service.
- Mahler D. B., Bryant R. W., Microleakage of Amalgam Alloys: An Update. JADA, Vol. 127 September 1996;1351-1356.
- Smales R. J., Rupinskas L., Clinical Behavior of Three Extended Carving Time Amalgams Over 3 Years. Department of Dentistry, University of Adelaide, South Australia.
- de Vries J., de Wat F. A., Eick J D., Polishing dental amalgam restorations. The Journal of Prosthetic Dentistry 1987;58(2):148-152.
Smales R. J., Gerke D. C., Clinical Behavior over Three Years of GS-80 and Lojic+ Amalgam Alloys, Aust. Dent. J. 1994;39(6):344-347.
The clinical performance of GS-80 and Lojic+ amalgam alloys was compared with that of Dispersalloy, Valiant-PhD, Lojic N and Permite amalgam alloys over periods of up to three years. The 114 restorations were placed by one dentist in 23 canine, 418 premolar and 673 molar permanent teeth of 301 adult patients treated in a private practice.
Direct and indirect clinical assessments were made of the restorations for failures (there were no true failures), and of the deterioration of four clinical factors. All restorations were rated as being either good (A) or adequate (B) for each of the four factors which, apart from surface texture, showed some slight but statistically significant clinical deterioration with time, Lojic+ and Permite showed clinically slight but statistically more surface roughness and marginal fracture, while Lojic+ and GS-80 showed more surface tarnishing, than did the other alloys. There were no statistically significant differences between the alloys for marginal staining.
Lojic+ was subjected to assessments of surface texture, tarnishing, marginal staining and marginal fracture. Assessment was done using photographic techniques and the results rated by rank. Lojic+ is reported as being easy to carve and polish giving a smooth finish. The differences in the properties evaluated are reported as being clinically insignificant.
Lojic Plus, The Dental Advisor, Volume 4, No. 5 Septermber/October 1994.
Lojic+ is a non-gamma 2, spherical amalgam with high compressive and tensile strength and low creep. It is available in 1-, 2-, 3- and 5-spill capsules in three setting times- slow, regular and fast (5-spill available in regular-set only). Twenty-two consultants evaluated Lojic+ in over 700 restorations.
Consultants were enthusiastic about the 5-spill size of Lojic+ capsules, especially for large restorations and core build-ups, since it reduced the number of capsules required. Lojic+ mixes homogeneously, is easy to load into the carrier, condenses well, and burnishes and carves nicely. No marginal ridge fractures were reported upon matrix removal. Ninety percent of the consultants felt the amalgamated mass has the right consistency and that the capsule to capsule consistency was excellent.
Lojic+ is highly recommended for amalgam restorations and core build-ups. It received a 91% approval rating.
Smales R J, Rupinskas L., Valiant-PhD and Lojic N amalgam alloys: four-year clinical results. Australian Dental Journal 1991;36(4):293-7.
From 1984 to 1986, 97 similar pairs of Valiant PhD and Lojic N amalgam restorations were placed at random by one dentist in Class II cavities prepared in 105 molar and op premolar permanent teeth of 73 patients treated in private practice. Assessments were made of the different handling properties of the two alloys and the effects of polishing, or otherwise, on the clinical behavior of the restorations. After periods of up to four years, there was only one restoration failure (from bulk fracture) for each alloy although both materials deteriorated over time. Both the polished and the unpolished restorations showed similar deterioration for marginal fracture and staining, and for surface tarnish, and their initially different surface textures became more similar during the study. Statistically, Lojic N restorations showed significantly more surface tarnish, but less marginal fracture than did Valiant PhD restorations, and the tarnishing did not appear to be related to the effects of corrosion.
Lojic and Valiant PhD were clinically evaluated over a 4 year period, Lojic is reported as being easier to pick up and faster to condense and its capsule system as being easier to use, Lojic was observed to show less marginal fracture and similar marginal staining.
Brown I. H., Miller D. R., Alloy Particle Shape and Sensitivity of High Copper Amalgams to Manipulative Variables. American Journal of Dentistry. 1993;6:248-254.
Compressive strength, dimensional change during hardening and residual mercury content of three high copper spherical particle amalgams (Tytin, Lojic and Valiant), two admix amalgams (Dispersalloy and Permite) and a conventional lathe cut amalgam (New True Dentalloy) were determined as a function of condensation pressure and trituration time. The properties of the three amalgams containing non spherical particles were markedly dependent on condensation pressure in the range 3 MPa to 14 MPa. Specimens condensed at 3 MPa showed substantially lower strength, greater expansion during hardening and higher residual mercury contents than did specimens condensed at 14 MPa. The three high copper spherical particle amalgams, on the other hand, were comparatively insensitive to condensation pressure. Variations in trituration between 5 and 12 seconds had little effect on the properties of any of the amalgams. (Am J Dent 1993; 6: 248-254).
Clinical significance: The fully hardened (7 day) compressive strength of Tytin, Lojic and Valiant showed only a slight dependence on condensation pressure. Dispersalloy and Permite were markedly dependent on condensation pressure being between 25-40% lower in compressive strength when lightly condensed.
The physical properties of Permite and Lojic are compared with competitors alloys under various condensing pressures. It is reported that Permite and Lojic are comparable to other alloys of the same type.
Roberts H. W. Lt Col, Coover M Lt Co, Meyer R, Mitchell W, Beasley B, Berridge J., Evaluation of Lojic+ Amalgam. USAF Dental Investigation Service.
To evaluate the clinical handling characteristics and selected physical properties of Lojic+ amalgam restorative material. The results of this evaluation will determine its suitability for use in federal dental service clinics. The Laboratory evaluation consisted of exterior amalgam capsule microscopic evaluation, mercury vapour readings during trituration, residual visible mercury retained in the capsules after trituration and microleakage.
Lojic+ was rated as acceptable for use by the Federal Dental Services with the following comments:
- good clinical handling features;
- easy to activate and open;
- good carving characteristics;
- Lojic+ is rated acceptable for general use in the federal dental services;
- The alloy demonstrated a dispersed-phase type of resistance to condensation which allowed establishment of contours and interproximal contacts.
Mahler D. B., Bryant R. W., Microleakage of Amalgam Alloys: An Update. JADA, Vol. 127 September 1996;1351-1356.
Using an in vitro air pressure test, the authors found a wide variation in the microleakage characteristics of amalgam restorations made from 33 recently manufactured precapsulated alloys. Spherical particle alloys as a group exhibited the highest microleakage values. When the authors changed the mercury / alloy ratios to produce 1 percent more mercury in the capsules by weight, microleakage decreased significantly. Because extensive microleakage of amalgam restorations has been related to increased post-operative sensitivity, the authors suggest that practitioners should be alert to this potential problem.
In this study to provide updated information to manufacturers and practitioners, Lojic demonstrated the lowest value of microleakage of all the spherical alloys tested. This result is consistent with other results documented.
Smales R. J., Rupinskas L.; Clinical Behavior of Three Extended Carving Time Amalgams Over 3 Years; Department of Dentistry, University of Adelaide, South Australia.
For the three ECT amalgam alloys used over three years:
- The two blended alloys were easier to handle than was the spherical alloy.
- The longer working times were useful for large ‘buildups’ and multiple restorations.
- Statistically, Lojic and Permite were better than Valiant-PhD for surface roughness and marginal fracture, the reverse being true for surface tarnishing.
- There were no ‘unsatisfactory’ rating assessments given for any of the materials.
Lojic was compared with Valiant-PhD for surface roughness, marginal fracture, marginal staining and tarnishing. Lojic (& Permite) is reported to perform better than Valiant in all tests except tarnishing. Only a slightly poorer tarnishing resistance is reported.
de Vries J., de Wat F. A., Eick J D., Polishing dental amalgam restorations. The Journal of Prosthetic Dentistry 1987;58(2):148-152.
Unpolished amalgam restorations are rough and therefore conductive to plaque accumulation. Finishing and polishing of amalgam restorations is an important component in the ultimate clinical success of the restorations. Unfortunately many dentists neglect this important step. Amalgam restorations may not be polished because an additional visit is required, certain polishing techniques may generate heat which might damage the pulp, or dentists may not know a method for finishing and polishing. Several polishing techniques have been reported in the literature. In this study we evaluated the surface produced by different polishing techniques on three dental amalgam alloys.
Lojic+, Dispersalloy and Unison amalgams were subjected to nine different polishing techniques and the resulting finish examined. Lojic+ is reported as producing the smoothest finish.
Osborne J. W., Three-year clinical performance of eight amalgam alloys. Am J Dent 1990;3:157-159.
Amalgam remains the most widely used restorative material and has undergone numerous changes in the past 20 years. In 1970, Mahler et al demonstrated that there was a difference in the clinical performance of alloys. They showed that there was a relationship between the mechanical property creep and the rate of fracture at the margins. The metallurgical reason for less fracture at the margins was the elimination of the corrosive, weak gamma-2 phase in amalgam by the addition of copper. Several high copper alloys were developed in the mid-70’s and early 80’s because of the Mahler concept of creep and the fracture of the margins. Later data, however, indicated that laboratory test for creep does not discriminate clinical difference between these new high copper alloys. Several short-term (1-3 years) clinical studies have been reported, but not until recently, the relationship between short-term (1-3 years) fracture at the margins and the long-term success of the alloys was not shown. Clinical studies have demonstrated that early fracture at the margins is a good predictor of amalgam restorations. The 1-year data has been published. The purpose of this report is to present the 3-year clinical data on eight amalgam alloys.
Permite, Lojic and six other alloys were clinically assessed for marginal fracture and surface tarnish after three years. Permite and Lojic are reported as performing better than Tytin for marginal fracture. Permite and Lojic have a lower rate of fracture.
Ellender G., Feik S., Gaviria C., The biocompatability testing of some dental amalgams in vivo. Australian Dental Journal 1990;35(6):497-504.
The biological responses to some dental amalgams were determined in vivo and compared with those of dental porcelain. The technique of implantation employed in the study addressed some of the vagaries of the recommended standard Practices for Biological Evaluation of Dental Materials (RSP) and considered both cellular responses (inflammation, infiltration and fibrogenic cell activity) and the organizational status of the resultant encapsulation. The implantation sites for both the experimental and control were biogeometrically similar unlike those currently recommended in RSP. At the end of the test period, all the dental amalgams tested caused minor responses reflected by the formation of thin capsules with an acceptable matrix organization. The Australian manufactured dental amalgams – Permite, Lojic, F400, New Ultrafine and GS80 all produced even capsules with quiescent cells. By one hundred days, the capsule around Dispersalloy, although generally well formed, showed some areas of cellular activity and matrix variability. The biological responses to all the dental amalgams examined were mild and considered to be acceptable for clinical usage. The matrix organization of enveloping capsules must be considered in the determination of the biocompatibility of a dental restorative material.
Lojic along with 4 other SDI alloys was studied for biocompatibility. Cellular response (inflammation, infiltration & fibrogenic cell activity) and organizational status of the resulting encapsulation was considered. Lojic is described as producing even capsules with quiescent cells and performed better than the control alloy, Dispersalloy. The biological response of Lojic is reported as being mild and considered to be acceptable for clinical usage.