A dramatic scene...

It depends on what's being said, how important each word is, and how your characters are reacting and responding. Good dialog, even if there's a large amount of it, can really fly by when reading if it's done well. For a dramatic scene, your characters have to be reacting and responding properly.

That said, don't add dialog just to pad the scene. I don't wanna sound trite - but use just as much dialog as you need to convey the scene and the drama necessary

Dialogue is what propels my story along, so I don't try to limit it as long as something's still happening storywise. What I try to do is break up the dialogue with action so I don't have two talking heads on a blank page.

Sometimes less is more, true. Depends on the writing style as well. Sometimes a single line can carry a knockout punch.

Sometimes less is more, and also silence is golden, especially in tense situations.

Remember that tense dialog can be more about what's NOT being said, than what is actually spoken. Ever been in a conversation where something is so completely avoided that it's actually louder than what is being said? Same thing.

It can also seem to be about one thing, when it's obvious to the reader/audience they're talking about something else completely. Remember the exchange at the end of the movie Serenity, where Mal seems to be asking Zoey about the ship, but you just know he's asking about Zoey:

"Think she'll hold together?"

"She's tore up plenty, but she'll fly true."

"Make sure everything's secure. Could be bumpy."

"Always is."

I just make sure, during rewrite, that every statement made is necessary and that nothing is repeated (unless the character has an annoying tendency to repeat himself, in which case I'll have another character hit him upside the head).

To me, editing dialog is the same as editing text, except that adverbs and similar weakening words can stay, because people normally use them in speech. But any sentence that's superfluous or repetitious has to go.

OK, if both characters feel safe enough to quietly discuss something, there aren't going to be many fireworks. So, without knowing the details, here are some possibilities to ratchet up the intensity:

- Time constraints: The characters need to hash something out now and don't have time to play nice.

- Third party: Someone else blurts out the main problem so the characters are forced to deal with it, or someone interrupts them with what should be an innocent question but which reveals the true issue.

- Outside action: Are they sitting in a restaurant, or hanging by ropes off the edge of a cliff? Is the setting safe or not? Does the intensity come from what they're saying or where they are?

Hope this helps.

Were either of them involved in the crime in question? In any case, just being at a crime scene should throw them off balance. If one of them is guilty, that should affect the dynamic. It'll affect the reader even more if the reader knows at this point who's guilty.

I assume this is 3rd person limited POV? Who is the POV character? The man or the woman? If it's the man, you can show him controlling his anger through internal monologue or have him misinterpreting her intent. If it's the woman, maybe she's confused at how he's reacting to her and lashes out.

The scene is more than simply the dialogue. The same words can come across in many different tones based on where they're said. Consider putting the same photograph in a gold embossed frame vs. tacking it on the wall with pins. If the intensity is missing, maybe it's not the words they're saying. Look at the whole picture of the scene. Is something missing?

Another thing to consider is subtext. Tension can increase by having the character say one thing but mean another (easily indicated from the POV character's viewpoint), or have the body language not match the words. If the man is trying to control anger, he'll be sending off mixed signals.

I think the type of details that the POV character notices will show a LOT about the emotion in the scene, and you might not need so much details.