Key Features of G-Force™ Diamonds

Uniform Crystals, Optimally Spaced



We mentioned earlier the goal of the G-Force diamond instrument manufacturing process was to create a more uniform layer of diamonds, while optimally spacing the crystals to create a faster, smoother, longer-lasting diamond. Brazing makes all of this possible, but the special processing creates the uniform layer and the optimally spaced crystals, which separate G-Force diamond instruments from all others. This increased speed and smooth "ride" are immediately evident to a dentist trying G-Force diamonds for the first time.

UNIFORM LAYER OF DIAMOND CRYSTALS: Both electroplated and standard brazed diamond instruments can suffer from high clusters and high crystals that can adversely affect performance. Since diamond instruments are rotating at very high speeds during use, a high crystal will prevent lower crystals both in front of and behind the high crystal from ever sharing in the cutting burden. So in the circumferential section where a high crystal or high cluster of crystals exists, only the outermost few crystal tips are doing any cutting. The clinician can feel this in the form of instrument vibration, bouncing, skipping, or an overall "rough feel" of the diamond when preparing a crown. Once the high outer crystals become dull, the instrument slows considerably, even though the lower surrounding crystals may still be perfectly sharp (Figure 6a, b and c).

Fig 6a: Electroplated coarse grit "A"	Fig. 6b: Electroplated coarse grit "B"
	Three leading premium diamonds showing high crystals which can adversely affect cutting speed and instrument life.
Fig. 6c: Brazed coarse grit

These high crystals are not a rare occurrence and can be found on virtually all diamonds to a greater or lesser degree - electroplated or brazed. However, not with G-Force diamonds.

G-Force diamonds minimize high spots in three primary ways:

1. Uniform Crystal Size
2. A Single Layer of Diamond Crystals
3. Brazing

1. Uniform Crystal Size:Most instruments use diamond crystals which can vary greatly in their aspect ratio. The aspect ratio is essentially the length-towidth ratio of the crystal. So a crystal that is 140µm x 100µm has an aspect ratio of 1.4:1. When these diamond crystals are attached to the blank, they may be on their sides or standing on their ends. If most of the crystals are on their sides at 100µm, and one of the crystals is standing on its end at 140µm, the one standing on end will be sitting 40% higher than the surrounding crystals. This is not ideal since the surrounding crystals at 100µm will not be sharing in the cutting burden. This problem is compounded as crystal size increases. The larger the crystal size, the more variance in aspect ratio.

G-Force selects synthetic diamonds that have a much lower variation in their aspect ratio while still maintaining sharp edges for cutting. So if the crystals are lying on their sides or standing on their ends, the result is virtually the same - the crystals extend nearly the same distance from the blank, and the height of the outer edges of the crystal layer is very consistent.

Instruments that utilize coarse and extra-coarse diamonds often cut fast at first, but can slow down quickly because only the few highest crystals are actually doing the work. Once those few higher crystals are dull, the diamond cutting speed drops considerably.

Even though the medium-sized diamond crystals on G-Force instruments are slightly smaller than the crystals typically found on other gross reduction instruments, more of the G-Force crystals are actually involved in the cutting. So the instruments cut faster. And, since more of the diamonds are sharing the cutting load, they don't wear out as fast, resulting in the potential for many more efficient and fast crown preparations from each G-Force diamond.

Fig. 8a: Premium brazed diamond instrument	Fig. 8b: Premium G-Force diamond instrument
Figures 8a shows a very large variation in the aspect ratios of its crystals, along with two high crystals along the top edge that will interfere with the ability of the surrounding crystals to participate in cutting. 8b shows the very uniform crystals used on the G-Force diamond, resulting in a very level cutting layer.

2. A Single Layer of Crystals: Electroplated diamonds have a combination of submerged and exposed diamonds which create high and low spots on the instrument. Similarly, brazed diamonds can end up with high and low spots as well if the diamonds are positioned too tightly together. When crystals are packed tightly together, some of the crystals can be pushed up higher than the others, creating a high cluster (Figure 9a, b).

Fig. 9a	Fig. 9b
Premium brazed diamond instruments showing crystals that have been pushed higher than the surrounding crystals.

G-Force crystals are applied in a single layer that creates spacing between crystals. So although some crystals may be adjacent to one another, they are not pushed higher than the others, leaving a single, uniform layer of diamond crystals. Again, this means nearly all the crystals share in the cutting burden, resulting in faster, smoother cuts. (Further benefits of this spacing will be explained later).

3. Brazing: As mentioned earlier, although brazing is not the total answer to a better diamond, it makes the new process possible. The above described uniform layer of optimally spaced crystals is not possible using currently known electroplating techniques. The low brazing layer of our process allows the crystals to bond at the same level to the instrument blank, without some of the crystals becoming submerged the way electroplated diamonds can. Brazing also leaves more of the diamond particle exposed for better abrasive properties. (Figure 10a, b)

Fig 10a: G-Force diamonds are brazed in a single layer where all of the crystals are bonded to the instrument shank at the same level.	Fig 10b: Premium non-brazed diamond crystals are often submerged.

Optimal Crystal Spacing.

Have you ever noticed that a bow saw used for cutting trees has a section of teeth, then a space, and then another section of teeth? This space exposes the full edge of the saw tooth while also aiding in debris removal. This can also be seen on circular saw blades (Figures 11a, b)

Fig. 11a: Crosscut saw blade	Fig 11 b: Combination blade

Which saw blade do you suppose cuts faster? Both blades have similar-sized teeth, but the combination blade on the right has space between the clusters of teeth, allowing it to cut faster. Combination saw blades are designed to provide a fast cut with a smooth finish - similar to G-Force diamonds.

The same principle can be applied to dental diamonds. Remember that a dental diamond is rotating at very high speeds. On an instrument with very closely packed crystals, cutting debris can get in the way and prevent the crystals from properly contacting the tooth. But an instrument with more space between the diamond crystals allows room for the debris to be efficiently removed while exposing more crystal edges for cutting.

Fig 12a: Schematic of a diamond with tightly spaced crystals	Fig 12b: G-Force diamond cross-section
Similar to the circular saw analogy, G-Force diamonds provide spacing between crystals to increase cutting speed, while providing a smooth surface finish.

This is why you see diamonds with spiral grooves in them. Some manufacturers explain this to be a water channel for cooler cutting. The author would argue that it is the interruption of the diamond layer that forces the crystals along the spiral line to engage the tooth more directly-and for a longer period of time-than with non-spiral instruments. Unfortunately, this only exposes the crystals along the spiral edge. So while some increases in speed can be experienced with a spiral diamond, the majority of crystals are still inhibited from cutting by surrounding crystals that vary in height (Figure 13a).

Fig 13a. Premium electroplated super-coarse spiral diamond showing exposed crystals along the edge of the spiral groove.	Fig 13b. Premium electroplated super-coarse spiral diamond after a single crown preparation. Note several crystals that were dislodged along the edge of the spiral.

Additionally, the crystals on the edges of a spiral cut diamond take the brunt of the cutting burden and are prone to shearing off (Figure 13b).

However, imagine a diamond instrument that created spacing throughout the entire head of the instrument. One where the burden of the cutting was shared not only along one edge of diamonds (as on spiral cut instruments), but across the entire abrasive head of the instrument. This is the essence of the optimized spacing of crystals of G-Force diamonds:

- Space that exposes more abrasive edges of more crystals
- Space that aids in debris removal and reduces clogging
- Space that improves water flow to keep the instrument cool

Figures 14a and 14b show a G-Force diamond at two different magnifications, showing the spacing pattern and how more edges of the crystals are exposed.

Fig.14a: G-Force diamond at 50x	Fig. 14b: G-Force diamond at 400x
G-Force's optimized spacing exposes the abrasive edges of more crystals, while reducing clogging and improving debris removal.

Instrument Quality.

Fig. 15a: Premium electroplated coarse-grit diamond

One might assume most diamond instruments would exhibit similar high quality. And the diamond crystals being used would be of nearly the same type and quality. But closer inspection of some instruments reveals quality can vary widely, and diamond crystal shape can profoundly and negatively affect cutting performance. In a recent in-house cutting test of premium brands, one instrument performed extremely slowly. A high-magnification photo of an unused instrument from the same batch showed a problem with the shape and quality of the diamond crystals being used.

Fig 15b: Premium G-Force medium-grit diamond

G-Force uses premium materials and high-quality manufactured diamond crystals in order to maintain superior product quality, and exacting consistency in diamond crystal size, crystal aspect ratios, and crystal friability (a measure of the crystal's resistance to shearing). So premium quality is consistent from instrument to instrument, and each instrument cuts as fast and smooth as the next. So you know what to expect with every G-Force and can count on the quality of performance with every tooth preparation.

Magnification of the diamond shown in Fig. 15a reveals diamond crystals with very rounded edges, significantly hindering its performance. The G-Force diamond shown in Fig. 15b uses manufactured crystals with consistent abrasive qualities.