Material and methods

62 patients – 39 women and 23 men – participated in the 1-year study. When the study began, the patients were aged between 23 and 71 (average: 47 years) and attended the Odontology Unit in Gothenburg as patients. They all required class II fillings in the lateral tooth area either because of primary caries or to replace existing amalgam fillings with secondary caries and micro fractures. Over the period January-June 2004 a total of 108 class II fillings was carried out using the composite material Latitude (AB Ardent, Sweden). There was no restriction on II cavities in terms or size or proximity to the enamel-cement border. The number of fillings varied between 1 and 7 per patient (table 1). The distribution of fillings in the dentition is shown in table 2.
The cavities were prepared using adhesive bonding procedure. In teeth with primary caries the preparation was carried out in accordance with the principles of dental-substance preserving minimally invasive treatment. The fillings were carried out in accordance with the manufacturer’s instructions. After drying and application of a matrix band, the cavity was etched with 37% phosphoric acid gel for 15-20 seconds using the total-etch principle and then flushed with water for 15-20 seconds. Two layers of Achieve (AB Ardent) adhesive material were applied and photo-hardened. Latitude was applied and every layer photo-hardened for 60 seconds. The fillings were polished to an even, shiny surface with a hard metal finishing burr and Sof-Lex disks. Polishing strips were used for proximal polishing as required.
Two observers examined each filling independently of one another and classified them in accordance with the US Public Health Service (USPHS) system, which is based on Ryge’s criteria (Ryge and Snyder 1973). These criteria (table 3) use an A-D scale, where A (Alfa) and B (Bravo) indicate “clinically acceptable” while C (Charlie) and D (Delta) indicate “not clinically acceptable”. This evaluation was performed at the baseline and after 6 and 12 months. The number of fillings examined after 12 months was 107 fillings (one patient no longer wished to participate in the study).

Results and discussion

The results of the evaluation of the fillings after 6 and 12 months are shown in tables 4 and 5. Between the baseline and 6-month inspection, few changes occurred in the parameters examined. At the 12-month inspection, one of fillings exhibited a fracture. Fractures are a common cause of failure in resin-based composite materials (Brunthaler et al., 2003). Table 5 shows that 9 approximal filling surfaces had no neighboring tooth. The remaining 133 had Alfa or Bravo values at the time of the baseline. At the 6-month inspection, one MO filling had no contact with the neighboring tooth. No secondary caries attack was recorded at the time of the 6-month or 12-month inspection. However, the short observational period of the study plays a part in the development of caries damage since studies have shown that secondary caries correlates directly with a longer period of observation (Brunthaler et al., 2003). The colour of the fillings at the time of baseline was assessed as falling within the Bravo criterion in 5 cases. In all other cases the colour of the filling did not differ appreciably from that of the adjoining tooth or neighboring teeth. Latitude showed excellent colour matching and shine and in many cases it was difficult to distinguish the filling from the tooth. The clean ability of the material was also considered good. Summarizing all the Alfa and Bravo assessments, the clinical acceptability level was 99% after 6 months and 98% after 12 months. However, the high success rate must be viewed against the background of the short follow-up time since the length of the period of observation correlates positively with the frequency of failure (Brunthaler et al., 2003), but at the same time means that Latitude stands up very well to comparison with newly published long-term studies.
To summaries, it may be stated that the quality assessment that we carried out showed that Latitude worked well as a restorative filling material in posterior cavities. The study will continue for 3 years in order to analyze whether Latitude continues to meet the requirements made of modern composite materials.

References

Brunthaler A, König F, Lucas T, Sperr W, Schedle A. 2003. Longevity of direct resin composite restorations in posterior teeth. Clin Oral Invest 7:63-70.

Ryge G, Snyder M. 1973. Evaluating the clinical quality of restorations. J Am Dent Assoc 87:369-377.

Table 1. The number of Latitude fillings carried out per patient 

Number of fillings per patient total number
1 2 3 4 5 6 7 patients fillings

Students 28 5 33 38

Lecturers 11 7 5 3 1 1 1 29 70

Total 39 12 5 3 1 1 1 62 108

Table 2. Class II-fillings carried out

Upper Lower mo/ total
jaw jaw do mod number
_____ 
premolars 31 40 47 24 71 (66%)

molars 21 16 32 5 37 (34%)

52 56 79 29 108
______________________________________ 

Table 3. Individual evaluation using Ryge criteria

Category Score Criteria

Anatomical A Form of the restoration is optimum, reproduces contours, cusp, plan, form, hollows and functional occlusal and approximal contacts.

B Slightly over or under-contoured. Somewhat loose contact. Some form of slight deviation from normal and/or functional anatomy.

C Anatomical form over or under contoured. Some form of deviation from normal and/or functional anatomy. The restoration needs to be revised or replaced within a reasonable time.

D Restoration partially or totally absent. Traumatic occlusion. Restoration causes pain in tooth or adjoining tissues.

Surface roughness A Smooth surface

B Somewhat rough surface or small pits, can be finished out. A single porosity on the occlusal surface may be tolerated.

C Deep pits, uneven grooves that cannot be finished out.
D Fractured or flaking surface.

Colour of A No difference in colour between restoration and adjoining tooth and/or neighboring teeth
restoration B Slight difference in colour, within the normal colour scale for teeth, shadow or translucency.
C Manifest difference in colour, not within the normal colour scale for teeth.
D Pronounced difference in colour between restoration and tooth. Aesthetically unacceptable colour, shadowing or translucency. 

Marginal A No visible sign of ditching along the margin.

joint B Visible signs of ditching along the margin. Insignificant and easy to level out.

C Somewhat deeper ditching. Exposed dentine. Treatment necessary within a reasonable time.

D Restoration mobile, fractured or partly absent; treatment as soon as possible.

Marginal A No discoloration.
discoloration B Slight discoloration that can be ignored or polished out.
C Significant marginal discoloration that cannot be polished out.
D Severe marginal discoloration. Very marked and adverse circumstances may be suspected, e.g. marginal micro-leakage, caries or risk of pulp involvement. Treatment as soon as possible.

Interproximal A Hard contact. Difficult to pass dental floss between restoration and neighboring
contacts tooth.
B Slight contact. Relatively easy to pass dental floss between restoration and neighboring tooth.
C No contact between restoration and neighboring tooth.

Caries A No evidence of caries in connection with restoration.
B Initial caries in connection with restoration.
C Caries on margin of restoration. Treatment within reasonable time.

Table 4. Number of fillings examined using USPHS criteria.
Result at baseline and after 6 and 12 months.

Baseline 6 months 12 months
(n=108) (n=108) (n=107) 

Anatomical form 98% A, 2% B 98% A, 2% B 99% A, 1% B

Surface roughness 100% A 100% A 100%A 

Colour 95% A, 5% B 95% A, 5% B 97% A, 3%B

Marginal joint 97% A, 3% B 97% A, 3% B 97% A, 2% B, 1% D

Marginal 98% A, 2% B 98% A, 2% B 98% A, 2% B
Discoloration

Secondary caries 100% A 100% A 100% A 

Survival 100% A 100% A 100% A

Table 5. Approximal contacts

Baseline (n=142) 6 months (n=142) 12 months (n=141) 

ab- present score ab- present score ab- present score 
sent A B C sent A B C sent A B C

mo/do 2 80 77 3 2 80 76 3 1 2 79 72 6 1

mod 7 53 51 2 7 53 51 2 7 53 51 2